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.
Forcada, N.; Álvarez, A. P.; Love, P.E.D; Edwards, D. J. Journal of infrastructure systems Vol. 23, num. 2, p. 04016034/1-04016034/11 DOI: 10.1061/(ASCE)IS.1943-555X.0000332 Data de publicació: 2017-06 Article en revista
There a paucity of systematic knowledge on the dynamics of rework in urban renewal projects even though such projects frequently exceed budget and schedule. The causal factors of rework and cost impact upon 69 Colombian public projects are examined. The nomenclature of Project, Organization and People (POP) is used to categorize causal variables and develop a generic systemic model of rework causation. Inadequate initial budgets, poor project design (which instigated changes during construction) and the socially inclusivity of contracts in Colombia (which employ local inexperienced people to conduct the required works), were the most significant contributors of rework. The developed model provides decision-makers and stakeholders with insights about the interdependencies and behaviour between key influencing variables in Colombian urban renewal projects and can be used to stimulate learning and process improvements in future projects.
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 the Operation and Maintenance (O&M) phase of an existing building, frequently, different systems are available to manage data about building maintenance. However, current practices do not integrate these systems and still manually process dispersed and unformatted data. The purpose of this paper is to investigate the potential benefits of the integration of data of Building Maintenance Management (BMM) in Building Information Modelling (BIM) in existing buildings. To do so, a questionnaire to evaluate the Facility Management practices in buildings is presented. This questionnaire is then used in the case study of Terrassa Campus at Universitat Politècnica de Catalunya (UPC). Conclusion demonstrated that the integration of BMM in BIM can enable support for maintenance decisions and increase the efficiency of the maintenance process.
Mobile applications and well-implemented technology can help governments increase the efficiency and effectiveness of information analysis and exchange. This paper presents a case study on the implementation of a mobile application to record accessibility information in the commercial buildings of Terrassa. To record and analyze the accessibility of the commercial buildings a taxonomy including general information and accessibility data was created. The analysis results confirmed the only 1% of the recorded commercial buildings fulfilled all accessible parameters. The main problems were in the access steps or ramps and also in the interior furniture. This data can then be implemented in other applications to be used by people with disabilities. Results also 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.
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%).
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
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.
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.
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.
Forcada, N.; Russinyol, G.; Macarulla, M.; Love, P.E.D Journal of civil engineering and management (Spausdinta) Vol. 20, num. 4, p. 445-465 DOI: 10.3846/13923730.2014.893917 Data de publicació: 2014-07-04 Article en revista
There is limited systematic knowledge available about the dynamics of rework in highway projects, despite the fact that they frequently exceed budget and schedule by more than 10%. A case study of a Spanish highway project, which experienced a significant cost overrun as a result of rework, is examined and the causal factors that contributed to its occurrence are determined. Through observation and subsequent analysis of interviews and documentation a high degree of interdependency existed between perceived causes of rework. This resulted in the nomenclature of Project, Organization and People to be adopted and used to develop the rework generic systemic model. Scope changes, high complexity, poor skill levels and unexpected underground services were found to be the most significant causes of rework. The developed model provides managers with insights about the interdependencies and behaviour between key influencing variables in highway projects and can be used to stimulate learning and process improvements in future highway projects.
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.
Love, P.E.D.; Edwards, D. J.; Irani, Z.; Forcada, N. Journal of civil engineering and management (Spausdinta) Vol. 20, num. 3, p. 315-329 DOI: 10.3846/13923730.2013.802725 Data de publicació: 2014-06-01 Article en revista
There is growing demand for cost effective and reliable floating production systems to maximize marginal and new deepwater fields worldwide. Floating Production Storage and Offloading (FPSO) vessels are considered to be the most economical and viable options to meet this demand. Yet, FPSO projects are prone to significant cost and schedule growth. On average, FPSOs have been reported to experience a 20% cost growth and are delayed by six months. Overruns and delays represent uncertainties for owners, contractors and financial institutions. In-depth interviews with twenty-three practitioners about their experiences with FPSO projects revealed that rework arising from design and construction errors were major contributors to cost and schedule growth. Key latent conditions contributing to rework are classified according to people, organization and project. Using retrospective sensemaking an examination of the determinant histories in a new build and conversion FPSO that experienced rework was undertaken. The sharing of experience(s) is deemed pivotal for reducing rework in future projects, particularly through the use of communities of practice that are able to stimulate situated learning to take place. A reduction in rework will not only reduce cost and schedule growth, improve operational performance and augment safety.
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.
Forcada, N.; Macarulla, M.; Love, P.E.D Journal of construction engineering and management (ASCE) Vol. 139, num. 4, p. 372-378 DOI: 10.1061/(ASCE)CO.1943-7862.0000603 Data de publicació: 2013-04 Article en revista
In Spain, the Ley de Ordenación de la Edificación (Building Regulation Act) has established compulsory warranties to ensure that buildings meet basic requirements with regard to functionality, general safety and structure, fireproofing, and use and habitability. Despite the requirements of this regulatory body, defects in newly built dwellings remain a pervasive problem, which has resulted in a plethora of complaints to the Instituto Nacional del Consumo (National Institute for Consumers’ Protection), which deals with consumer protection in Spain. In this paper, a total of 2,351 post-handover defects derived from four Spanish builders and seven residential developments are classified according to their location, subcontract, and element. The research reveals that the most common defects identified by customers at handover were incomplete tile grouting and incorrect fixtures and fittings in toilets. In addition, failure to apply second coats of paint to walls was deemed a problematic issue. Typical surface/appearance defects were found to include floor or wall unevenness, stains, mess, and small cracks and marks, primarily caused by lack of protection. In areas where fixtures, fittings, and finishes were of a similar nature, such as the kitchen and bathroom, defect types also arose. Determining the location, subcontract, and element where defects occur in residential buildings can provide invaluable knowledge about areas where builders are likely to make errors or mistakes or take deliberate shortcuts during construction. Thus, emphasis on quality control and supervision of subcontract trades, especially in the identified areas, and during the final stages of residential construction, are critical to ensure that defects are reduced.
In Spain, the Ley de Ordenación de la Edificación (Building Regulation Act) has established compulsory warranties to ensure that
buildings meet basic requirements with regard to functionality, general safety and structure, fireproofing, and use and habitability. Despite the
requirements of this regulatory body, defects in newly built dwellings remain a pervasive problem, which has resulted in a plethora of
complaints to the
Instituto Nacional del Consumo
(National Institute for Consumers
Protection), which deals with consumer protection
in Spain. In this paper, a total of 2,351 post-handover defects derived from four Spanish builders and seven residential developments
are classified according to their location, subcontract, and element. The research reveals that the most common defects identified by
customers at handover were incomplete tile grouting and incorrect fixtures and fittings in toilets. In addition, failure to apply second coats
of paint to walls was deemed a problematic issue. Typical surface/appearance defects were found to include floor or wall unevenness, stains,
mess, and small cracks and marks, primarily caused by lack of protection. In areas where fixtures, fittings, and finishes were of a similar
nature, such as the kitchen and bathroom, defect types also arose. Determining the location, subcontract, and element where defects occur in
residential buildings can provide invaluable knowledge about areas where builders are likely to make errors or mistakes or take deliberate
shortcuts during construction. Thus, emphasis on quality control and supervision of subcontract trades, especially in the identified areas, and
during the final stages of residential construction, are critical to ensure that defects are reduced.
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.
Although effective communication is identified as a key indicator of project performan
communication aspects on contractors’ evaluation are not yet included. This paper aims to
review the most relevant contributions on the specific literature in order to design a survey to
test for the parameters that affect effective communication among
Construction Agents (CA),
i.e. PM’s, builder, designer and other professionals participants, during the construction
process of the project. The survey will be based on the experience and perceptions of the
corresponding professionals in Spain. The availa
bility of these par
ameters is crucial and it
basic information for
procedures and tools for the evaluation and
selection management of CAs.
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.
Underground transportation systems are big energy consumers (e.g. 63,1 millions of kWh / year), and have significant impacts on energy consumption at a regional scale. One third of the networks' 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 is to develop advanced technologies for optimal and scalable control of metro stations that will produce a 5% saving in non-traction electricity consumption in one year, which is equivalent to the electricity consumed in more than 700 households. The project's main outcomes will be the creation of systems for optimized integrated energy management, and the development of a decision support system to drive mid-term investments. SEAM4US will integrate additional energy metering and sensor-actuator networks with the existing systems (e.g. surveillance, passenger information and train scheduling), by means of middleware as abstraction layer, to acquire grounded user, environmental and scheduling data. The data set will update and enable a set of adaptive energy consumption and environmental models to proactively and optimally control the metro stations. The consortium consists of a large metro network operator, TMB; a major player in energy-efficient system management sector, COFELY; building and environmental physics and construction experts UNIVPM and UPC, respectively; R&D experts in middleware, FhG FIT and VTT; R&D experts in user and agent-based scheduling modeling, ALMENDE and UNIK; system integrator, CNET.
Gangolells, M.; Casals, M.; Gasso, S.; Forcada, N.; Roca, X.; Fuertes, A. Building and environment Vol. 46, num. 5, p. 1023-1037 DOI: 10.1016/j.buildenv.2010.11.004 Data de publicació: 2011-05-02 Article en revista
The most common challenges and obstacles encountered by construction organizations during the process of implementing and using environmental management systems are related to the inherent peculiarities of the construction sector. Several studies have shown that one of the issues involving the greatest level of uncertainty is the identification and assessment of environmental impacts. In order to improve the identification of the significance of environmental impacts of construction projects and sites, which will lead to greater efficiency and robustness in environmental management systems, this paper extends the systematic approach for identifying and assessing potential adverse environmental impacts at the pre-construction stage presented in Gangolells et al. (2009) by introducing the assessment of the concerns of interested parties. By considering concerns amongst internal and external interested parties, one can assess the significance of environmental impacts taking into account not only the severity of the impacts but also local perceptions and international challenges, thereby ensuring that the determination of the impacts’ significance is appropriate to the particular socioeconomic and biophysical environments surrounding construction sites. In order to quantitatively measure concerns among internal and external interested parties for each of the 37 environmental impacts related to a construction project, we developed corresponding indicators and assessment scales with the help of a panel of experts. A series of χ2 tests conducted over 76 new-start construction projects clearly revealed that the severity of environmental impacts is not correlated with the concerns of interested parties. The development of a formal quantitative method and the subsequent definition of a threshold make it possible to obtain advance knowledge of the significance – and, therefore, the acceptability – of each potential environmental impact for a particular construction project. A total score for each construction project alternative is also obtained, so the improved methodology provides a consistent basis for comparing construction companies and construction sites. Finally, two case studies are presented in order to demonstrate the benefits of the improved methodology.