The thermal behaviour of a building is often underestimated or neglected during its construction and operation stages. In recent years, the heat flux meter (HFM) method has been commonly used to determine the U-value, a key parameter for assessing the thermal quality of the building envelope in steady-state conditions. However, this non-invasive test takes at least 72 h to execute, the accuracy is
14–28%, and it is not reliable for non-homogeneous building elements. An alternative technique is based on infrared thermography (IRT). Although it is generally used for qualitative analysis, quantitative internal IRT methods may also be adopted for in-situ measurement of the U-value. This research presents
a method for determining in-situ U-values using quantitative internal IRT with a deviation of 1–2% for single-leaf walls and 3–4% for multi-leaf walls. It takes 2–3 h and can be used to provide information about the building envelope for the future refurbishment of existing buildings or to check the thermal behaviour of new building façades according to their design parameters.
Most existing commercial building energy management systems (BEMS) are reactive rule-based. This means that an action is produced when an event occurs. In consequence, these systems cannot predict future scenarios and anticipate events to optimize building operation. This paper presents the procedure of implementing a predictive control strategy in a commercial BEMS for boilers in buildings, and describes the results achieved. The proposed control is based on a neural network that turns on the boiler each day at the optimum time, according to the surrounding environment, to achieve thermal comfort levels at the beginning of the working day. The control strategy presented in this paper is compared with the current control strategy implemented in BEMS that is based on scheduled on/off control. The control strategy was tested during one heating season and a set of key performance indicators were used to assess the benefits of the proposed control strategy. The results showed that the implementation of predictive control in a BEMS for building boilers can reduce the energy required to heat the building by around 20% without compromising the user’s comfort.
Forcada, N.; Gangolells, M.; Casals, M.; Macarulla, M. Journal of construction engineering and management (ASCE) Vol. 143, num. 8, p. 04017032/1-04017032/9 DOI: 10.1061/(ASCE)CO.1943-7862.0001324 Data de publicació: 2017-08 Article en revista
Rework adversely impacts the performance of building projects. In this study, data were analyzed from 788 construction incidents in 40 Spanish building projects to determine the influence of project and managerial characteristics on rework costs. Finally, regression analysis was used to understand the relationship between the contributing factors, and to determine a model for rework prediction.Interestingly, the rework prediction model showed that only the original contract value (OCV) and the project location in relation to the company’s headquarters contribute to the regression model. The Project type, the Type of organization, the Type of contract and the original contract duration (OCD) which represents the magnitude and complexity of a project, were represented by the OCV. This model for rework prediction based on original project conditions enables strategies to be put in place prior to the start of construction, to minimize uncertainties and reduce the impact on project cost and schedule, and thus improve productivity.
Predictive control is the strategy that has the greatest reported benefits when it is implemented in a building energy management system. Predictive control requires low-order models to assess different scenarios and determine which strategy should be implemented to achieve a good compromise between comfort, energy consumption and energy cost. Usually, a deterministic approach is used to create low-order models to estimate the indoor CO2 concentration using the differential equation of the tracer-gas mass balance. However, the use of stochastic differential equations based on the tracer-gas mass balance is not common. The objective of this paper is to assess the potential of creating predictive models for a specific room using for the first time a stochastic grey-box modelling approach to estimate future CO2 concentrations. First of all, a set of stochastic differential equations are defined. Then, the model parameters are estimated using a maximum likelihood method. Different models are defined, and tested using a set of statistical methods. The approach used combines physical knowledge and information embedded in the monitored data to identify a suitable parametrization for a simple model that is more accurate than commonly used deterministic approaches. As a consequence, predictive control can be easily implemented in energy management systems.
In this paper a model for the dynamic simulation of fans used in mechanical air supply systems is described. Thanks to this model, the behavior of fans subject to control by variable frequency drives (VFD) can be predicted, which includes power absorbed by the fan and expected ventilation rates. Hence, it can help design energy control systems for buildings. The proposed model was based on the Modelica language and was developed from the dynamic phasor domain representation, because this representation is a trade-off between the basic non transient representation, that is computationally efficient but cannot describe fan dynamics, and the dynamic time domain model, that is the most representative one but computationally very demanding. A comparison among these models showed that, within fan frequency variations typical of ventilation systems in buildings, the phasor domain model is as representative as the more complex dynamic time domain model in terms of prediction of the dynamic behavior, that is neglected by the basic non transient model. Moreover, the new phasor domain model was validated against measured data relative to a fan installed in a subway station in Barcelona. Thanks to this model, energy consumption of dynamically driven fans can be estimated at the simulation stage, at the expense of a reasonable computational effort.
In recent years, a growing concern has been how to determine the actual thermal behaviour of façades in their operational stage, in order to establish appropriate energy-saving measures. This paper aims at comparing standardized methods for obtaining the actual thermal transmittance of existing buildings’ façades, specifically the average method and the dynamic method defined by ISO 9869-1:2014, to verify which best fits theoretical values. The paper also aims to promote the use of the dynamic method, and facilitate its implementation. Differences between the theoretical U-value and the measured U-value obtained using the average and dynamic methods were calculated in three case studies, and then compared. The results showed that differences between the theoretical and the measured U-value were lower when the dynamic method was used. Particularly, when testing conditions were not optimal, the use of the dynamic method significantly improved the fit with the theoretical value. Moreover, measurements of the U-value using the dynamic method with a sufficiently large dataset showed a better fit to the theoretical U-value than the results of other dynamic methods proposed by authors. Further research should consider the optimum size of the dataset to obtain a measured U-value that is correctly adjusted to the theoretical U-value.
Buildings in Europe are responsible of 40% of the final energy consumption. With the aim to
accomplish the European 20/20/20 targets, buildings play an important role. Moreover, public buildings
should exemplify the best practices in terms of energy efficiency. In this context this paper describes an
energy management system for buildings developed in the GESTENSIS project. The system is composed by 5
modules that give tools to building managers to optimize the energy consumption. The building managers
have a set of metrics to understand how their building is working and to know if the building performance is
decreasing. The system also supports building managers in their daily building operation, optimizing the
different types of spaces (corridors, lecture rooms and PC rooms). The system also helps building managers
to carry out maintenance activities. It is expected to reduce 15.26 % of the gas consumption and 37.59 % of
the electricity consumption.
Casals, M.; Gangolells, M.; Macarulla, M.; Fuertes, A.; Jones, R.; Pahl, S.; Ruiz, M. European Conference on Product and Process Modelling p. 573-577 Data de presentació: 2016-09-07 Presentació treball a congrés
Housing represents about 29% of the total energy consumption in Europe and contributes with
around 20% of emissions (European Commission 2013). Social housing represents about 12% of the total European
housing stock and therefore is a significant target for energy efficiency measures by governments of
EU member states. This paper is aimed at exploring how an innovative serious game could contribute to energy
consumption and carbon emissions reduction in social housing by increasing the social tenants’ understanding
and engagement in energy efficiency. The proposed solution is being developed under the auspices
of the EnerGAware project (Energy Game for Awareness of energy efficiency in social housing communities),
funded by the European Commission under the Horizon 2020 programme.
Le Guilly, T.; Skou, A.; Olsen, P.; Madsen, P.; M. Albano; Ferreira, L.; Pinho, L.; Casals, M.; Macarulla, M.; Gangolells, M. IEEE International Conference on Emerging Technologies and Factory Automation p. 1-8 DOI: 10.1109/ETFA.2016.7733715 Data de presentació: 2016-09-06 Presentació treball a congrés
This paper presents how the ICT infrastructure
developed in the European ENCOURAGE project, centered
around a message oriented middleware, enabled energy savings
in buildings and households. The components of the middleware,
as well as the supervisory control strategy, are overviewed, to
support the presentation of the results and how they could be
achieved. The main results are presented on three of the pilots of
the project, a first one consisting of a single household, a second
one of a residential neighborhood, and a third one in a university
Inspections generate large amounts of information that have to be recorded and
Although different strategies to implement new technologies to improve the inspection
process are being developed, the industry and the municipalities still relies on paper
based techniques. Therefore, problems such as potential loss of information,
misunderstandings, and unclear instruction among different parties often occur.
This paper presents a mobile application for improving the inspection process (Pick&Go).
The application is based on a methodology that uses images and tags as a unique entry
point. Pick&Go was then validated in Terrassa’s City Council to record accessibility
information in the commercial buildings of Terrassa.
Results demonstrate that mobile and well-implemented technology can help
governments save money and be more efficient. The use of this application simplified
and reduced the time needed to record accessibility information while the standardized
information helped them obtaining consistent data to aid the development of learning
techniques. The tracked information can also be used to inform citizens about the
assessment of the commercial building accessibility in the city.
Lighting systems are usually one of the largest electrical end-uses in underground metro stations. Taking into account that budget restrictions in publicly owned companies hinder energy efficiency retrofit projects that require high initial investments, affordable energy saving strategies are needed. This paper presents a low-cost approach for reducing lighting electricity use in underground stations, without affecting passengers' comfort or the metro operator's service. For this purpose, an adaptive lighting strategy of dimming the illuminance levels of artificial light sources has been developed. Dimming controls are based on the occupancy of the station, and the preventive maintenance and cleaning cycles of the luminaires. The stations' monthly occupancy patterns are defined through the k-means clustering technique. To illustrate its effectiveness, the method was applied to 115 underground stations of the Barcelona metro network. The results revealed overall electricity savings of 255.47 MW h on a biannual basis, which represents 36.22% of the stations' baseline lighting consumption. Individual energy savings were found to range from 25 to 87.5 MW h/year in the stations of the Barcelona metro network, depending on the number and profile of station users. The research findings will undoubtedly be useful for the future energy efficiency project plans of worldwide metro operators and managers of other underground spaces.
Casals, M.; Gangolells, M.; Forcada, N.; Macarulla, M.; Giretti, A.; Vaccarini, M. Applied energy Vol. 166, p. 150-164 DOI: 10.1016/j.apenergy.2016.01.029 Data de publicació: 2016-03-15 Article en revista
Several previous research initiatives have highlighted the role of Information and Communication Technologies (ICT) as key enablers for decreasing energy usage in buildings. However, few advances have been achieved in underground public spaces. This paper introduces a novel intelligent energy management system for underground stations. The system implements artificial intelligence solutions for autonomous building system control, based on advanced control algorithms that can learn from previous operations and situations. The robustness needed to operate in public spaces is achieved through a seamlessly integrated monitoring grid with self-diagnosis mechanisms. A middleware platform integrates existing devices, subsystems and newly deployed sensor-actuator networks. Results obtained during the implementation of the system in a prototype underground station showed potential yearly energy savings ranging between 74,336 and 87,339 kW h. The highest energy savings potential was found in the ventilation subsystem (30.6% +/- 2.0%), followed by the lighting system (24.1% +/- 1.9%) and escalators (8.5% +/- 1.9%).
Smart building systems are opening up new markets, nevertheless the implementation of these novel technologies still lacks suitable and proven whole engineering solutions in complex buildings. This paper presents a detailed approach for the ventilation control of an underground space, as an example of application of the developed solution to a very harsh environment but also highly demanding in terms of energy consumption. The underground spaces are characterized by a particular thermal behavior, because of the continuous and huge thermal exchange they have with the outside, via the openings and the ground surrounding the majority of the building. The main objective of the developed methodology is to reduce energy consumption of ventilation control while maintaining acceptable comfort levels: succeeding in achieving this twofold goal in a real station and the generalization of the approach are the most relevant contributions of the paper. The developed solution is based on a Model-based Predictive Control algorithm used together with a proper monitoring platform. The model predictive control is based on a Bayesian environmental prediction model, which works in cooperation with a weather forecast web service, schedule-based predictions about trains and external fans and an occupancy detection system to appraise the real amount of people. The prediction model develops scenarios useful to allow the controller acting in advance in order to adapt the system to the current and future conditions of use, taking profit of the knowledge of the real ventilation demand. Finally, the proposed control architecture is applied to the Passeig de Gràcia metro station in Barcelona as a case study, validating the usefulness of the proposed approach and obtaining more than 30% of energy savings in the ventilation system, while maintaining the pre-existing comfort levels. The saving percentage values estimated by simulation are confirmed by the direct measures continuously taken on site through energy-meters.
Gangolells, M.; Casals, M.; Forcada, N.; Macarulla, M.; Giretti, A. Renewable and sustainable energy reviews Vol. 55, p. 662-667 DOI: 10.1016/j.rser.2015.11.006 Data de publicació: 2016-03-01 Article en revista
Although energy management systems are expected to result in decreased energy consumption, it is important not to overlook the energy used until commissioning (including raw materials acquisition, manufacturing and transportation) and during the usage phase (including operation and maintenance). This paper examines the energy performance of an intelligent energy management system for underground metro stations. The results show that the energy management system has high energy performance in terms of energy payback time and energy return factor, due to its low cumulative energy demand and its potential for energy savings. When we assumed that the lifespan of energy management systems may vary between 5 and 10 years, their cumulative energy demand was found to range between 505,316 and 852,493 MJp eq. In all cases, the operating energy was found to far outweigh the embodied energy (68-81%). The energy management system was implemented in a pilot underground station and was found to provide an energy saving of 13.2±1.1% of the total energy consumption of the pilot station. The energy payback time of the energy management system for underground stations was found to range between 40 and 55 days. Consequently, the system pays back between 33 and 91 times the energy invested in it. The results of this research provide valuable information for stakeholders in the energy management systems industry, as they contribute to ascertaining the sustainability of products.
Although inspections occur during construction or at handover, customers do not normally participate. This situation creates a gap between the quality perceived by both contractors and customers. An analysis of 52 552 handover defects in 2179 flats in Spain is presented which identified their nature, the building element and trade where these defects are located. These results are compared with previous studies that analysed defects detected during the construction stage and those that remain after handing over the building to the client. The research reveals that structural defects are resolved during construction due to existing quality standards. However, other aesthetic and functional defects remain and/or arise at handover. Some defects are not resolved until customers complain after they first occupy the dwelling. Many functional defects arise due to the lack of involvement of end users in the early project stages.
This is an Accepted Manuscript of an article published by Taylor & Francis Group in Building research and information on 20/05/2015, available online: http://www.tandfonline.com/doi/abs/10.1080/09613218.2015.1039284
Gaspar, K.; Casals, M.; Gangolells, M. Journal of performance of constructed facilities Vol. 30, num. 1, p. 04014187- DOI: 10.1061/(ASCE)CF.1943-5509.0000693 Data de publicació: 2016-02 Article en revista
Façades play an important role in buildings’ energy demand, and their state of conservation obviously influences thermal performance. The energy performance gap in existing residential buildings due to façade conservation status has not been analyzed in depth. In order to facilitate the systematic analysis of this influence, a system for classifying façades and their corresponding anomalies was developed for the first time. The classification system includes 23 types of façades and eight types of anomalies. It was verified by a panel of experts, and a case study was carried out with a sample of 154 buildings. An analysis of the results showed that the classification system is useful for a future analysis of the energy performance gap in existing residential buildings.
This research contributes to the assessment of on-site fuel consumption and the resulting carbon dioxide emissions due to earthworks-related processes in residential building projects, prior to the start of the construction phase. Several studies have been carried out on this subject, and have demonstrated the considerable environmental impact of earthworks activities in terms of fuel consumption. However, no methods have been proposed to estimate on-site fuel consumption during the planning stage. This paper presents a quantitative method to predict fuel consumption before the construction phase. The calculations were based on information contained in construction project documents and the definition of equipment load factors. Load factors were characterized for the typical equipment that is used in earthworks in residential building projects (excavators, loaders and compactors), taking into considering the type of soil, the type of surface and the duration of use. We also analyzed transport fuel consumption, because of its high impact in terms of pollution. The proposed method was then applied to a case study that illustrated its practical use and benefits. The predictive method can be used as an assessment tool for residential construction projects, to measure the environmental impact in terms of on-site fuel consumption. Consequently, it provides a significant basis for future methods to compare construction projects.
Gangolells, M.; Casals, M.; Forcada, N.; Macarulla, M.; Cuerva, E. Journal of cleaner production Vol. 112, num. 5, p. 3895-3904 DOI: 10.1016/j.jclepro.2015.05.105 Data de publicació: 2016-01-20 Article en revista
Energy performance certificate databases are a key tool for mapping national building stock and thus fostering greater overall energy efficiency. This paper presents an insight into the energy performance of residential and tertiary sector buildings in Spain, through an analysis of the first 129,635 energy performance certificates issued for existing buildings, collected by the Catalan Institute of Energy. Most of the residential buildings or building units that were studied were “E” class (53.6%). Single-family houses were found to use more energy on average (248.0 kWhp/m2) than individual dwellings (183.2 kWhp/m2). Tertiary sector buildings were found to have slightly better energy performance (26.4% of buildings were rated “D class”), with an average energy consumption of 317.8 kWhp/m2. Modern buildings consume less energy, as they must meet the higher energy performance requirements stated in thermal building regulations. Residential buildings or building units located in hotter climate zones consume slightly less energy than those located in colder zones, mainly because heating accounts for a high percentage of overall energy expenditure (70–75% in residential buildings). A significant proportion of the energy consumed in tertiary sector buildings is for lighting (37.2%). This research defines the current energy consumption baseline of existing buildings in Spain. The results can help to prioritize energy conservation efforts according to building type, construction period, climate zone and specific end-uses. They may also help public authorities to plan future energy policies, and construction practitioners to identify market segments and business strategies.
The main objective of the EnerGAware project is to achieve a 15-30% energy consumption and emissions reduction in a social housing pilot and increase the social tenants’ understanding and engagement in energy efficiency.
The EnerGAware project will develop and test, in publically owned social housing, a serious game that will be linked to the actual energy consumption (smart meter data) of the game user’s home and embedded in social media and networking tools. The solution fits within all three ICT areas suggested in the topic EE-11 scope: gaming, social networking and personalised data driven applications.
The EnerGAware solution will provide an innovative IT ecosystem in which users can design their own virtual home and Avatar and learn about the potential energy savings from installing energy-efficiency measures and changing user behaviour, whilst maintaining the comfort of their Avatar. The user will need to learn to balance the energy consumption, comfort and financial cost of their actions. Energy savings achieved both virtually in the game, calculated by building performance simulation, and in reality, in the users’ actual homes, measured through smart meter data, will enable progression in the serious game. The social media features will provide users a platform to share data of their achievements, compete with each other, give energy advice, as well as, join together to form virtual energy communities.
The EnerGAware solution will be developed and deployed with the ‘cleanweb’ philosophy in mind: “Capital light, Quick to market and Quick to scale”, therefore the EnerGAware project will aim to go beyond just testing in a social housing pilot, but will seek commercial exploitation of the solution at the end of the project, through our industrial partners, in particular EDF Energy, a global energy provider, with 38 million European energy customers.
This paper presents for the first time the results of a life cycle assessment study for an intelligent energy management system. We considered material acquisition, manufacturing, transportation, assembly, operation and maintenance stages. The results show that the assembly phase had an environmental impact of 897 Eco-indicator 99 points that was mainly due to the monitoring subsystem (87.80%). When the analysis was extended to cover the use phase, the environmental impact ranged from 1963 (useful life of 5 years) to 3029 Eco-indicator 99 points (useful life of 10 years). The environmental impact of the use stage was found to represent 54–70% of the total, whereas the assembly stage represented 46–30%. The maintenance phase contributed to a very small extent to the total environmental impact (less than 0.5%). In any case, the impact on resources was the largest (about 51%), whereas the human health damage category amounted to approximately 35% and the ecosystem quality damage category represented about 14% of the total impact.
In this paper, the implementation of effective waste management practices in construction projects and sites is analyzed, using data from a survey answered by 74 Spanish construction companies based in Catalonia. Most commonly implemented practices were found to be on-site cleanliness and order, correct storage of raw materials, and prioritization of the nearest authorized waste managers. The least widespread practices were the use of a mobile crusher on site, the creation of individualized drawings for each construction site, and the dissemination of the contents of the waste management plan to all workers, to help them to meet its requirements. Waste regulations for construction and demolition, and the corresponding construction waste management facilities, were designed before the recession in the Spanish construction sector. Current waste generation rates are still below predicted levels, and the infrastructure was designed for five times more waste generation. Even so, the percentage of reused and recycled waste currently amounts to 43%. Survey respondents highlighted various instruments and measures that would make the management of construction and demolition waste more sustainable. Most of the opportunities identified by construction firms are within the scope of government and related to a combined system of bonus and penalties and the establishment of environmental awareness and training programmes for all the stakeholders. Within the scope of authorized waste managers, firms suggested improvements such as the standardization of fees, a reduction of the time until the issue of waste management certificates, a higher number of inspections, and a change in the current model of a few large construction waste management facilities. This research is useful to better understand the current status of construction and demolition waste management in construction projects and sites. Thus, the results of this research will guide policy makers and relevant stakeholders such as contractors, clients, architects and engineers to achieve the EU target of recovering 70% of construction and demolition waste in 2020. In this sense, reliable information can help governments and professional associations to set future C&D waste management regulations, training programmes and dissemination tools, inspections, etc.
This paper outlines the decision support system that is being developing for the performance
and financial analysis of the SEAM4US system, concerned with the implementation of an Intelligent
Energy Management system for Underground Stations. A critical aspect for the design and
implementation of advanced sustainable solutions for the energy saving in complex buildings is the
assessment of the effectiveness of the approach in terms of both the amount of the energy saving and of
the cost benefits. The required dynamic analysis of the building behaviours under different operational
conditions makes it difficult to figure out the relevant operational scenarios. The paper describes a
scenario analysis tool that simulates the operation of an underground station in different climatic
conditions and with different system technology arrangements. The paper provides cost benefit
analysis under different operational scenarios and proposes suitable business models for the overall
Underground transportation systems are big energy consumers, and have significant impacts
on energy consumption at a regional scale. One third of a network’s energy is required for operating
the subsystems of metro stations and surroundings, such as ventilation, vertical transportation
and lightning. Although a relatively small percentage of energy can be saved with an optimal management
of these subsystems, a large energy saving in absolute terms can be obtained. The objective
of SEAM4US project is to develop advanced technologies for optimal and scalable control of metro
stations that will generate at least 5% saving in non-traction electricity consumption in one year. The
SEAM4US system, and the demonstrating pilot running on the Passeig de Gràcia Metro station in
Barcelona, represent a significant contribution and drive to the opening of new markets by developing
and prototyping new ICT-intensive approaches to energy saving for underground spaces, generally,
and, more specifically, for the metro station market. This paper describes the solution approach of the
intelligent energy management system at Passeig De Gràcia metro station of Barcelona and the expected
Defects are a non-value adding activity seriously affecting the performance and productivity in construction projects that spend unnecessary cost, time materials and manpower. Non-quality represent the 4% of the contract value of the new dwelling or renovation and produce other adverse consequences such as
temporal deviations, affectations in project sustainability as well as safety and reduction ofproject performance.
Developing tools that bring awareness ofthe potential quality risks can help organizations improve their quality performance. Moreover, there are significantly growing evidence linking BIM benefits to decision-making tools.
This paper presents the implementation of a quantitative methodology to forecast potential quality risks into a 40 model (BIM-QRC). BIM-QRC proposes 40 multiple views related to the needs of each practitioner. The methodology ranks the significance of all quality risks of a construction project and is able to compare several
design options in terms of quality performance. While the existing methodology is useful to get consciousness
ofthe quality risks of a project, the adaptive visualisation of different business views improves the understanding
and comprehension of the quality performance of a project and facilitates decision making for both designers and contractors.
The main objective ofthis paper is to study the resilience of current Spanish residential building stock to climate change impacts. Results showed that 72% of current residential building stock in Spain is not
performing properly according to current climate conditions. During the 1981 - 201 O period, mean annual degree days based at l 5ºC diminished in 74% of Spanish provincial capitals, with an average rate decrease of 10.1 % in relation to the 1950-1979 period. Significant accelerating positive trends in cooling degree days and important
decreases in heating degree days were found in the twenty-first century. Strategies and measures to support climate change adaptation of existing and future built environments through building codes and standards have also been explored.
Underground transportation systems are big energy consumers and have significant impacts on energy consumption at a regional scale. The literature has revealed that the energy consumption for non-traction purposes may be of the same magnitude as the energy used to move rolling stock, and in some cases even greater. However, most of the research conducted so far has focused on the energy demand of rolling stock. This paper investigates the electricity consumption of an underground metro station using data from on-site surveys and measurements. With an average consumption of 217.64 kWh/m(2)/year, the breakdown revealed that the lighting system dominated the underground station's energy consumption (37%). Illuminated advertising signs were found to be responsible for 14% of the total energy consumption, and ventilation accounted for another 14%. The rest of the energy consumption was attributed to systems such as mobile phone signal antenna (12%), the vertical transportation system (8%) and small power devices (5%). Accurate information on energy consumption for non-traction usage is useful for future implementation of energy conservation measures in underground stations, which could result in a reduction of operating costs in the long run.
The building industry is noted for its repeated building defects causing cost increases and time delays during construction. In Spain, despite the Ley de Ordenación de la Edificación (Building Regulation Act), which establishes a general framework to promote overall building quality, construction defects in residential buildings remain a pervasive problem. An analysis of 3647 construction defects is presented which identified the location within the building, subcontractors and building element in 68 residential building developments undertaken by two large Spanish contractors. The research reveals that the most common defects that arise during construction are related to the stability of the structure and inappropriate installation of roofs and facades. These technical faults are caused by poor workmanship rather than by the quality of the materials or products used. By comparing these results with a previous study on defects after handover, it can be concluded that while the nature of defects during construction is basically technical, at handover it is aesthetic or technical.
The EU-funded project called SEAM4US (Sustainable Energy mAnageMent for Underground Stations) is targeted to define advanced control systems for cost-effective management of subway stations, which will be applied to the pilot "Passeig de Gracia" station of the metro network in Barcelona (Spain). To this aim, the environmental conditions of the station must be monitored in real-time. In particular, this paper focuses on the challenge of air flows estimation because this is one of the most critical yet tough variables to be monitored: expensive and intrusive measurement methodologies cannot be used extensively. So a novel methodology, based on the use of ordinary measurement probes and analytical methods and capable of identifying in real-time the intensity and dynamics of ventilation that is taking place, will be suggested. The information deriving from real-time measurements and analyses will be used to dynamically adjust the mechanical ventilation burden, that is currently relying on the station's air supply system, thanks to the adoption of intelligent control systems. Our study is based on both a measurement survey carried out in the aforementioned station and numeric analyses.
The EU-funded project called SEAM4US (Sustainable Energy mAnageMent for Underground Stations) is targeted to define advanced control systems for cost-effective management of subway stations, which will be applied to the pilot
Currently, the European building sector is responsible for more than 40% of the energy consumed and many studies have demonstrated the relevance of its greenhouse gas emissions. According to several research authors, a limited attention has been directed towards the environmental impact of the construction phase, mainly because of the lack of data or because the analysis is complicated. Other researches reviewed the environmental implications of construction site energy use and electricity generation based on the analysis of energy costs at national level and concluded that the true significance on on-site construction energy consumption was higher than understood.
This dissertation contributes to assess in advance the construction site energy consumption of those processes related to earthworks and concrete structure activities.
After the literature review, this research investigates the construction site consumption agents and their classification parameters in terms of specific consumption, load factors, engine efficiency and emission factors. A database of the main construction site equipment is worked out to homogenize the technical information related to the machine operation parameters. Then, in order to calculate equipment’s energy consumption, a predictive model is developed, analyzing electric and diesel consumption features. Load factors are further investigated in case of excavators and tower cranes because of their importance in terms of energy consumption.
The further step of the methodology consists on the prediction of the construction activities energy consumption, analyzing equipment productivity and developing 12 case studies related to the earthworks and concrete structures activities. For each of the identified activities, energy consumption and related carbon dioxide emission of 1 m3 of element realized or of 1 m3 of excavated soil are calculated. Confirming some previous studies, the analysis underlines that earthworks and diaphragm walls are the construction activities that have the greatest impact in term of gasoline consumption and consequent carbon dioxide emission.
This dissertation documents the verification and validation of the developed methodology in two real construction sites of new residential buildings. The on-site energy monitoring through meters allowed the collection of real data used to verify the developed methodology. The validation ensures that theories and assumptions underlying the conceptual methodology are correct and reasonable. The two case studies also illustrate the practical use of the developed methodology.
At a design level, this research proposes several indicators that can be used in different typologically comparable projects. Indicators are useful for designers or clients that have to compare different
design alternatives of residential construction projects and determine which one is more “sustainable” from the point of view of its on-site energy consumption.
Finally, this dissertation concludes by outlining the main contributions of this research. Further possible developments of this research, some of them already started, are commented on and proposed as future work.
The research findings fill a gap in the body of knowledge by presenting an effective way to evaluate the significance of on-site environmental impacts of municipal engineering works prior to the construction stage. First, 42 on-site environmental impacts of municipal engineering works were identified by means of a process-oriented approach. Then, 46 indicators and their corresponding significance limits were determined on the basis of a statistical analysis of 25 new-build and remodelling municipal engineering projects. In order to ensure the objectivity of the assessment process, direct and indirect indicators were always based on quantitative data from the municipal engineering project documents. Finally, two case studies were analysed and found to illustrate the practical use of the proposed model. The model highlights the significant environmental impacts of a particular municipal engineering project prior to the construction stage. Consequently, preventive actions can be planned and implemented during on-site activities. The results of the model also allow a comparison of proposed municipal engineering projects and alternatives with respect to the overall on-site environmental impact and the absolute importance of a particular environmental aspect. These findings are useful within the framework of the environmental impact assessment process, as they help to improve the identification and evaluation of on-site environmental aspects of municipal engineering works. The findings may also be of use to construction companies that are willing to implement an environmental management system or simply wish to improve on-site environmental performance in municipal engineering projects.
This paper is aimed at describing an intelligent environmental aware energy management system for underground stations, developed under the auspices of the European project Sustainable Energy mAnageMent for Underground Stations (SEAM4US) and implemented in a pilot underground station. With an average consumption of 217.64kWh/m2·year, the breakdown revealed that the lighting system dominates the energy consumption of the station followed by illuminated advertising signs and ventilation. The SEAM4US energy
management system has been designed to provide smart autonomous control ofthe ventilation, lighting and vertical transportation trough the core, monitoring and control subsystems. Several control policies were simulated and expected energy savings were found to range between 11 % and 20% ofthe total energy consumption.
Building sector is contributing to the 36% of the C02 emissions in Europe, and consurning
the 40% of final energy consurnption. In this context this paper presents a new approach developed under the
ENCOURAGE project to carry out the user awareness. The proposed user awareness is based on a set of KPls,
and done at two levels: energy mangers and university campus users. The KPfs are displayed to the energy
managers using a web-platform. With that information energy managers are able to identify actions and control
algorithms to reduce the energy consun1ption. In the other hand, the university campus users awareness it is
done sending messages to the user through the Twitter platform. A set of messages are defined, andan algorithm
decides which messages have to be published in each moment. The aim is to promote good practices in the use
La literatura sosté que les empreses del sector de la construcció poden reduir els costos derivats dels ¿rework¿ implementant sistemes de gestió de qualitat. Els reptes i obstacles més comuns als que s¿enfronten les empreses del sector de la construcció durant la implementació i operació dels sistemes de gestió de la qualitat estan relacionats amb ¿com¿ la informació pot ser enregistrada d¿una manera eficaç, i ¿què¿ es pot fer amb aquesta informació enregistrada. La tesi té com a objectiu millorar el procés d¿enregistrament de defectes en les empreses del sector de la construcció, i proposar mètodes i eines per utilitzar els defectes enregistrats en obra per tal de prevenir i reduir els ¿rework¿ en les empreses del sector de la construcció. La tesi s¿inicia amb el desenvolupament d¿un mètode conceptual per caracteritzar defectes. El model proposat està basat en models preexistents, però tenint en compte el context del sector residencial espanyol. El model es basa en l¿enumeració d¿una sèrie de paràmetres que permeten caracteritzar els defectes. El model final inclou 6 paràmetres, cada un d¿ells inclou un llistat de paraules estandarditzades amb les corresponents definicions.Els llistat de paraules estandarditzades estan basats en estudis previs, però adaptant-los al context espanyol. Cal destacar però que en termes de defectes, no existeixen llistes estandarditzades. Per aquesta raó, aquesta tesi inclou el desenvolupament d¿una taxonomia de defectes pel sector de la construcció espanyol. Aquesta taxonomia consta de 15 categories principals i 19 subcategories. La tesi continua amb el desenvolupament d¿una metodologia per capturar defectes en el sector de la construcció. La metodologia es implementada en una eina informàtica, anomenada MoBuild. El sistema es basa en la captura d¿imatges i en l¿etiquetatge d¿aquestes. D¿aquesta manera la informació es captura de manera estructurada, fet que possibilita el posterior anàlisi estadístic de la informació capturada. La nova estratègia implementada en l¿aplicació MoBuild permet als professionals reduir el temps del procés d¿enregistrament, facilitant la implementació de sistemes de gestió de la qualitat, tals com la ISO 9000 en empreses del sector industrial. La recerca proposa també una metodologia quantitativa per identificar els riscos de qualitat derivats de la construcció d¿edificis residencials durant les etapes de pre-construcció. El punt fort d¿aquesta metodologia rau en el fet que ajuda als dissenyadors a considerar explícitament la qualitat del projecte constructiu durant el procés de disseny. Els dissenyadors poden comparar diferents alternatives de disseny, i quantificar els riscos de qualitat d¿un projecte de construcció sense que les seves aptituds creatives es vegin restringides. La metodologia és especialment valuosa per als dissenyadors amb menys experiència, als quals els hi manquen les habilitats requerides i el coneixement per a reconèixer els riscos de qualitat derivats de la construcció dels seus dissenys. La metodologia també serveix com a eina d¿assessorament per a empreses constructores. Aquestes poden utilitzar la metodologia per a determinar i quantificar els riscos de qualitat derivats dels projectes constructius que aquests duguin a terme. D¿aquestes manera les empreses constructores poden preparar i planificar els seus projectes constructius i optimitzar els seus recursos i activitats.Finalment, aquesta tesi analitza la qualitat percebuda pels usuaris finals dels edificis residencials un cop aquests en comencen a fer ús. La tesi utilitza diferents mètodes estadístics per mostrar la utilitat de les dades de qualitat enregistrades per les empreses del sector de la construcció. L¿objectiu és ressaltar el rol essencial que tenen les dades enregistrades en les activitats d¿una empresa, en particular donant evidències de quins beneficis poden aportar els sistemes de la gestió de la qualitat.
Literature usually suggests that construction organization can reduce the costs derived from rework implementing quality management systems. Most common challenges and obstacles that construction organizations face during the implementation process and use of quality management systems are related to "how" the information can be recorded in an effective way, and "what" can be done with the recorded information.
The aim of this dissertation is to focus on improving the defects recording process in the construction industry, and to propose methods and tools to use defects recorded on-site to prevent and reduce rework in the construction industry.
The dissertation starts with the development of a conceptual model used to characterize defects. The current model is based on previously existing models and their adaptation to the context of the Spanish residential building sector. The model is based on the enumeration of the parameters that allow characterizing defects. The final model includes 6 parameters, with a list of standardized words and their definitions.
The pre-established vocabulary lists are based on existing classification systems proposed by recognised organisations, authors and research reports, but then adapted to the Spanish context. However, in terms of defects, no standardised list exists. For this reason a taxonomy of defects is further developed for the Spanish construction sector. The aforementioned taxonomy consists of 15 main categories and 19 subcategories.
The dissertation continues with the development of a methodology to track defects in the construction industry and its implementation in an IT tool called MoBuild. The obtained tracking system is based on images and tags. The strengths the abovementioned tracking system is to record information in a structured way and enable further statistical analysis of the recorded information. The new approach implemented in the MoBuild application allows practitioners to reduce the time of the recording process, facilitating the implementation of quality management systems, such as ISO 9000 in construction organizations.
Furthermore, research proposes a quantitative methodology for dealing with potential adverse quality risks during the pre-construction stages of residential buildings and other similar types of constructions. The strength of this methodology lies in the fact that it helps designers to explicitly consider on-site quality during the design process. Designers can compare several design alternatives during the design phase, and determine the corresponding overall quality risk levels of a construction project without their creative talents being restricted. The methodology is especially worthwhile for those less-experienced designers who lack the required skills and knowledge to recognize quality risks in developing optimal designs.
The methodology also serves as an assessment tool for construction companies. It can be used to measure the potential quality risks of construction projects and its subsequent construction activities. The suggested methodology also allows construction companies to optimize their on-site performance in the quality domain during the planning and preparation stages.
Finally, this dissertation analyses the quality perceived by the end users during the post-handover stage. Different statistical methods are used to demonstrate the usefulness of the recorded data for the construction organizations. The aim is to highlight the essential role that records play in the operation of a quality company, in particular by providing essential evidence of the operation of quality systems.
The aforementioned statistical analysis determines the type of defects detected; the elements affected by defects; the areas where defects are detected; which subcontractors produce defects; the source of the detected defects; the origin of the detected defects and; the influence of the building type and its characteristics in the number of defects detected.
Forcada, N.; Macarulla, M.; Gangolells, M.; Casals, M.; Fuertes, A.; Roca, X. Journal of performance of constructed facilities Vol. 27, num. 6, p. 756-762 DOI: 10.1061/(ASCE)CF.1943-5509.0000368 Data de publicació: 2013-12-01 Article en revista
In Spain, the high levels of inexperienced workers and the long chains of subcontracting contribute to poor quality of dwellings. Although the Ley reguladora de la subcontratación en el Sector de la Construcción (Subcontracting law) has established quality measures, the number of customer complaints is still increasing. In this paper, a total of 2351 post-handover defects derived from four Spanish builders and seven residential developments are classified according to their source and origin. The research reveals that the most common defects identified by customers at post-handover were derived from bad workmanship, and were related to construction errors and omissions. Typical defects were found to include incorrect installation, appearance defects, missing item or task mainly related to finishing and considered to be minor. No defects were caused by poor design as they are mainly detected and resolved during construction, or become apparent after some years of use. This study demonstrates the negative impact of re-doing defective work during the final stages of construction, and provides knowledge to define measures to improve the quality of the finished buildings, such as understanding customer expectations and preferences, training programs for workers, specialization of subcontractors and tighten the external controls prior to handover.
In Spain, the high levels of inexperienced workers and the long chains of subcontracting contribute to the poor quality of dwellings.
Ley reguladora de la subcontratación en el Sector de la Construcción
(subcontracting law) has established quality measures, the
number of customer complaints is still increasing. In this paper, a total of 2,351 posthandover defects derived from four Spanish builders and
seven residential developments are classi
ed according to their source and origin. The research reveals that the most common defects identi
by customers at posthandover were derived from bad workmanship and were related to construction errors and omissions. Typical defects were
defects were caused by poor design because they are mainly detected and resolved during construction or become apparent after some years of
use. This study demonstrates the negative impact of redoing defective work during the
nal stages of construction and provides knowledge to
ne measures to improve the quality of the
nished buildings, such as understanding customer expectations and preferences, training
programs for workers, specialization of subcontractors, and tightening external controls prior to handover.
Macarulla, M.; Forcada, N.; Casals, M.; Gangolells, M.; Fuertes, A.; Roca, X. Journal of construction engineering and management (ASCE) Vol. 139, num. 8, p. 968-976 DOI: 10.1061/(ASCE)CO.1943-7862.0000669 Data de publicació: 2013-08 Article en revista
Defects produce economic and temporal deviations in construction projects. Although learning from past experiences can help reduce defects and their consequences, usually data is not easily available, or is poorly structured and difficult to analyze. Several structured classification systems for defects exist, but regionally specific construction activities make the data unviable for research use. This paper presents the development and the validation of a defects' classification system for the Spanish housing sector. From the analysis of the existing defect classification systems, a first draft was developed to be discussed and improved in a series of workshops done by a panel of experts. Afterwards, the final classification was validated by experts' interviews. The experts evaluated the epistemological adequacy and reusability of the proposed classification system. The results demonstrate the suitability of the classification system. In addition the validation revealed that the classification can be implemented in tracking systems, and it can be used to analyze defects in the Spanish housing sector. Finally, the classification was used in a case study to analyze the real use and it demonstrated the potential uses of the classification.
Fuertes, A.; Casals, M.; Gangolells, M.; Forcada, N.; Macarulla, M.; Roca, X. Journal of cleaner production Vol. 52, p. 425-437 DOI: 10.1016/j.jclepro.2013.02.005 Data de publicació: 2013-08-01 Article en revista
Despite the increasing efforts made by the construction sector to reduce the environmental impact of
their processes, construction sites are still a major source of pollution and adverse impacts on the
environment. This paper aims to improve the understanding of construction-related environmental
impacts by identifying on-site causal factors and associated immediate circumstances during construc-
tion processes for residential building projects. Based on the literature and focus group
ndings, we have
developed a construction-related Environmental Impact Causal Model consisting of a process-oriented
causal network of thirty-nine environmental impacts, forty-
ve causal factors and over two hundred
causal relationships. It is intended to contribute to a reduction in construction-related environmental
impacts on building sites by supporting contractors and other decision-makers in the early identi
of factors that are likely to lead to impacts or to exacerbate their consequences, as well as the later
environmental performance evaluation and control. The causal model is validated by investigating over a
hundred environmental incidents. Finally, possible methods to improve construction-related environ-
mental performance are suggested.
Gangolells, M.; Casals, M.; Forcada, N.; Fuertes, A.; Roca, X. Journal of construction engineering and management (ASCE) Vol. 139, num. 2, p. 138-147 DOI: 10.1061/(ASCE)CO.1943-7862.0000579 Data de publicació: 2013-02 Article en revista
Certifiable management-system standards apply similar management techniques and principles, but each system still tends to have a separate structure in construction companies. Research and practice have demonstrated that management tasks may be duplicated when standards are implemented in parallel. Consequently, integrated management systems are strongly advocated. However, existing literature demonstrates that the integration of planning and control instruments involves a high level of uncertainty. This paper presents an innovative model to enhance the integration of environmental-and health and safety-management systems in construction companies, focusing on the subsystems for identifying, assessing, and operationally controlling environmental aspects and health and safety hazards and using risk as an integrating factor. The findings of this study have direct implications for both designers and contractors because the model helps to explicitly consider on-site environmental impacts and construction-worker safety during the design process and offers on-site guidance to eliminate the remaining impacts and risks or reduce them to acceptable levels. A case study is reported to illustrate the practical use of the proposed model and its benefits.
Certifiable management-system standards apply similar management techniques and principles, but each system still tends to have
a separate structure in construction companies. Research and practice have demonstrated that management tasks may be duplicated when
standards are implemented in parallel. Consequently, integrated management systems are strongly advocated. However, existing literature
demonstrates that the integration of planning and control instruments involves a high level of uncertainty. This paper presents an innovative
model to enhance the integration of environmental- and health and safety
management systems in construction companies, focusing on the
subsystems for identifying, assessing, and operationally controlling environmental aspects and health and safety hazards and using risk as an
integrating factor. The findings of this study have direct implications for both designers and contractors because the model helps to explicitly
consider on-site environmental impacts and construction-worker safety during the design process and offers on-site guidance to eliminate the
remaining impacts and risks or reduce them to acceptable levels. A case study is reported to illustrate the practical use of the proposed model
and its benefits.
Knowledge management (KM) has been studied extensively in recent years. Some consider knowledge to be the most strategically important resource for any company, but the fragmented, project-based and task-oriented nature of construction work makes it more difficult to implement KM in this sector.
This paper presents a survey of perceptions of KM implementation in the Spanish construction sector and compares the results obtained from design and construction firms. Data were collected from the leading civil engineering companies in Spain.
The survey found that the Spanish construction industry is aware of the benefits of KM but that systematic KM is not generally implemented. The findings clearly demonstrate that changes in organizational culture are critical to successful KM. The survey also revealed some distinctions between the KM perception of design firms and that of construction firms.
Article publicat originalment a "Revista ingeniería de construcción", vol. 27, núm. 3, Desembre 2012, p. 103-127. ISSN 0716 - 2952. http://www.ricuc.cl/index.php/ric/article/view/417/pdf
Este artículo tiene como objetivo favorecer la implementación de sistemas integrados de gestión ambiental y de seguridad salud en empresas constructoras, centrándose en el subsistema de control de los impactos ambientales y los riesgos de seguridad y salud en obra.
La gran compatibilidad que presentan los requerimientos vinculados al control operacional establecidos en la normas ISO 14001:2004 y OHSAS 18001:2007 así como las interacciones existentes entre impactos ambientales y riesgos de seguridad y salud (Gangolells et al., 2009, Gangolells et al., 2010) han motivado el desarrollo de una ontología que permite construir un modelo integrado para el control operacional en obras de construcción. La aproximación desarrollada está fuertemente influenciada por la metodología de Noy y McGuiness (2001) y modela los conceptos clave y las relaciones del dominio de forma estructurada, extensibe, flexible, reutilizable y compartible. Esta aproximación basada en ontologías ha sido implementada mediante Protégé 3.4 beta y correctamente evaluada utilizando cuestiones de competencia, verificaciones internas y entrevistas de validación con expertos. Este artículo desarrolla la primera aproximación que permite representar, compartir, reutilizar y gestionar el conocimiento relacionado con el control operacional integrado en obra de las incidencias medioambientales y de seguridad y salud y sienta las bases para poder superar la mayoría de las barreras que las empresas constructoras deben afrontar durante el proceso de implementación de un sistema de gestión integrada.
The resilíence of the current Spanish residentia[ building stock to increased temperatures is modelled. Homogenized dai[y temperature data recorded at 50 Spanish meteorological stations for the periods 1950-1979 and 1981-2010 were used to investigate anticipated dimate warming on the Spanish residential building stock by means of the degree-day method. Impacts on residential buildings were investigated for three different future time periods (2011-2040, 2041-2070 and 2071-2100) for three representative Spanish provincial capitals. Future dimate change scenarios comprising two statistical downscaling methods, three general circulation mode[s and two carbon emission scenarios were used to project [ocal dimate. Results show that 72% of current residential building stock in Spain is thermally unprotected. In addítion, the energy demand for heating the building sector in Spain is expected to decrease by between 30% (Barcelona, B2 scenario) and 36% (Valencia, A2 scenario) by 2100, while the respective energy demand for cooling could increase by between 107% (Valencia, B2 scenario) and 296% (Madrid, A2 scenario) by 2100. To inerease resilience to higher winter and summer temperatures, strategies for modifying the built environment are needed, particu[arly for the role of building codes and standards.
Forcada, N.; Macarulla, M.; Fuertes, A.; Casals, M.; Gangolells, M.; Roca, X. Journal of performance of constructed facilities Vol. 26, num. 4, p. 433-440 DOI: 10.1061/(ASCE)CF.1943-5509.0000225 Data de publicació: 2012-08 Article en revista
Clients’ lack of involvement in defining quality requirements for dwellings built by developers leads to a perception of poor quality at the time of purchase. The research presented in this paper aims to broaden previous research on defects by analyzing the defects that remain in the post-handover stage, which usually lasts 12 months after the handover period, and identifying the factors that influence the appearance of these defects, determining whether a significant difference exists in the quality of the two main residential building types built by developers: flats and detached houses. It also analyzes and discusses the areas and elements in which the defects were detected. The data were obtained from client complaint forms completed after the handover of 95 dwellings in Spain. The data were then statistically analyzed using a t-test analysis, a Pearson’s parametric correlation, and a chi-square test. The research reveals that clients detect more defects in flats than in detached houses. The lower quality of the materials used in flats and the tighter schedule to which flats are subject may cause these differences.