Performance-based building and innovation: balancing client and industry needs

One reason for the interest in performance-based building is that it is commonly advocated as a powerful way of enhancing innovation performance by articulating building performance outcomes, and by offering relevant procurement actors the discretion to innovate to meet these performance requirements more effectively and/or efficiently. The paper argues that the current approach to performance-based building assumes that relevant actors have the capacity, ability and motivation to innovate from a business perspective. It is proposed that the prevailing conceptualization of PBB is too restrictive and should be broadened explicitly to accommodate the required business logic that must be in place before actors will innovate. The relevant performance-based building and innovation literature is synthesized to support the assertion. The paper concludes with an innovation-focused definition of performance-based building.     

High-performance weather-protective flashings

Typical problem areas associated with weather-protective flashing are identified, based on a comprehensive investigation of building damage cases in Norway. A total of 175 assignment reports associated with damaged flashing for the period between 1963 and 2001 are analysed. The investigation clearly shows that certain faults and deficiencies are recurring items. Windowsill/weatherboard flashings comprise as much as 41% of the building damage cases associated with weather-protective flashing. Damage in connection with parapet flashing comprises 27% of all cases included in this investigation. With few exceptions, instances of damage are located in Norway's coastal areas. Existing flashing solutions in the Norwegian Building Research Institute's Building Research Design Sheets have been further developed, based on the results from the analysis. Improved high-performance flashing solutions are presented for a number of typical problem areas. An illustrated summary of problems frequently encountered with different flashing variants is also presented. Finally, recommended best-practice flashing solutions for a number of typical problem areas are provided. The results will be implemented in the Building Research Design Sheets, and will also be used as a basis for the carrying out of new field studies and laboratory investigations.     

Durability and the factor method of ISO 15686-1

Interest in the service life of buildings and components and the future need for maintenance is growing, and the methodology for service life planning is starting to appear in standards. The standard ISO 15686 prescribes a factor methodology for deciding about the expected service life of a component with a prescribed probability of earlier failure. The methodology is based on extensive knowledge about materials and building technology, and examples of the use of this methodology on building components are of value for the discussion on service life planning. Results from a condition survey of timber windows are used to define the service life and effect of the factor method in the Standard. Wood is a very variable material, and for wooden windows maintenance plays a key role in the durability of the component. In this instance, condition assessment is, therefore, not sufficient to estimate the service life. Information about former maintenance and refurbishment is also needed. The results from a condition assessment and the house owner's answers to a questionnaire are combined to evaluate the estimated service life of the windows. The factors for the standardized method for estimating service life with a given confidence limit are shown to have a wide range in values that give considerable uncertainty to the practical use of the standardized methodology. For example, it is shown that the estimated service life with an 80% confidence limit is much lower than the average service life. Thus, the question is posed whether there is any meaning in estimating the lower limit of service life.     

Concise exterior lighting simulation methodology

A methodology is proposed which integrates advanced photogrammetric and computer-aided design (CAD) software with lighting simulation tools. The methodology consists of preparing a CAD model from digital photographs and then using lighting simulation packages to carry out the lighting analysis and produce a photo-realistic image. The latter can serve as a decision tool to the lighting designer. The methodology was specifically adapted for illumination studies of buildings of historical and/or architectural importance. The methodology was validated quantitatively by comparing simulation results with on-site field luminance measurements. The rendered photo-realistic images produced also compared favourably with photographs indicating the reliability and effectiveness of the overall simulation procedure.     

Performance-based building regulation: current situation and future needs

Although performance-based building regulations are in use or under development in numerous countries worldwide, there remain significant challenges in adequately identifying and defining performance, in understanding and addressing diverse societal expectations, and in establishing robust performance-based regulatory systems. These challenges become intensified as the building construction market becomes increasingly global, with the resulting expectation that building regulatory instruments remain valid across borders and do not create barriers to trade, while at the same time address local and national needs without compromising local cultural and societal norms. Many of these issues are just now beginning to be explored, and there is significant opportunity and need for future research and development in these areas.     

Service life planning and performance requirements

Service life planning comprises a model for the determination of a reasonable expected service life for buildings and components, and it establishes a routine for the assessment of design alternatives. A design option is considered reasonable when it meets or exceeds performance requirements over time that have been drawn up specifically for the specific project. Due to this assessment reference, there is a very evident link to the concept of performance-based building. Any stakeholder involved in the value chain or in the design process of the building, as well as regulators and building users, can express performance requirements. Identified requirements, both in relevance and in quality, will vary with the stakeholder and his/her perspective of interest. As building sector manufacturers develop most products with reference to standards rather than with reference to specific requirements, there is no direct link from user requirements to the product design. Instead, the building designer has the responsibility to ensure performance requirements are met by the performance of products integrated into the design. As these design decisions also have to be made at the material and component level, a performance-based building would benefit from an established rationale that enables the communication of performance requirements across the relevant system levels in the relevant design processes. A path for the connection of the established concepts of service life planning and performance-based building is presented. The aim is to identify key elements that need to be developed for the successful linkage of performance-based building with service life planning.     

Safety design practices in residential buildings in Saudi Arabia

A survey of current safety practices in the design of residential buildings in Saudi Arabia identified deficiencies in governance and design procedures. A systematic safety compliance checklist was developed to address these deficiencies incorporating existing local safety instructions and international safety codes and standards. Checklist use is intended to ensure compliance with minimal safety requirements in the design of residential buildings.     

Quantification methods of technical building performance

A building performance assessment toolkit was developed for use by large corporate owners and building portfolio managers in the US. A variety of technical performance aspects are addressed such as energy, lighting, thermal comfort, maintenance and indoor air quality. Every assessment is based on a normative and objective Performance Indicator (PI). For easy data capture and calculation of PIs, the toolkit was implemented in a web hosted form, enabling facility managers and staff to collect the data during a walk-through enabled by PDA-based data entry. The current set of performance indicators is discussed and the results of the first benchmarks, most notably the energy benchmarks, are reported.     

Modelling of enhanced passive and conventional cooling systems

This study modelled a recently completed typical steel-framed speculative office development in the UK. It investigated the comparative performance of the building for various servicing regimes. These included natural and mechanical ventilation, two types of active fabric energy storage (FES) system (AirDeck and AirCore), air-conditioning (a conventional all-air system and chilled ceiling with mechanical ventilation), and mixed-mode solutions combining some of the above approaches. The assessment covered both summer and winter (heating) performance. The main objective was to evaluate overall performance of these systems in terms of thermal comfort and energy use and to compare the findings with more conventional servicing options for the same building. The study demonstrates that active FES can enhance thermal comfort while reducing energy use and emissions. In comparison with conventionally and naturally ventilated systems, the studied FES systems reduced temperature excess hours and peak temperatures, supplied cooler air as a result of overnight cooling, and reduced chiller consumption and boiler ratings as well as emissions. The annual operating costs of these active FES systems increase energy costs by only 13% over that of the naturally ventilated option. The mixed-mode solutions reduce them by over 35% when compared with all-mechanically cooled alternatives.     

Simulation and analysis of airborne cross-contamination routes due to the operation of building drainage and vent systems

Recent concerns about the role of the drainage and vent systems installed in high-rise and other buildings in the possible spread of airborne contamination have highlighted the need for simulations capable of predicting system response when subject to multiple and random events. Such simulations would allow designers to predict the possible contamination routes established as a result of failures of the system, e.g. trap seal loss and/or the influence of dried-out traps. In addition, the simulations proposed would provide diagnostic tools in the event of cross-contamination. Mathematical solutions are used to simulate the system unsteady water and entrained airflows, and the application of these simulations to predict likely contamination routes. The AIRNET simulation is employed to represent the unsteady air and water down-flow conditions in the network, the associated propagation of air pressure transients and trap response. The simulation can provide a design and standards development tool as well as a forensic and diagnostic tool for the investigation of suspected cross-contamination. The simulations confirm that cross-contamination routes result from normal operation and random failure conditions, including system surcharge and trap depletion due to, for example, poor maintenance. It suggests that simulation predictions have an important role in ascertaining potential hazards, as well as a forensic role.     

Key determinants of performance of design-bid-build projects in Singapore

What are the factors affecting the performance of design-bid-build projects? Ten performance metrics and 60 factors are identified that project team members can use to measure and manage the success levels of construction projects in four broad categories: cost, time, quality and administrative burden. A survey and correlation analysis of 65 design-bid-build projects in Singapore is used to suggest the factors that affect each performance metric significantly. Contractor characteristics are the key determinants affecting the highest number of performance metrics. The most significant variable is the contractor's past record for completing projects on budget and to an acceptable level of quality. Based on this evidence, it is recommended that clients and consultants pay closer attention to a wider array of characteristics (not just the initial price) involving contractor selection. Another key determinant is the project character with the most important variable being the percentage of repetitive elements.     

Residential building damage and natural perils: Australian examples and issues

The most important natural perils in Australia are tropical cyclones, earthquakes, bushfires, thunderstorms, floods, landslides and tsunamis. However, as far as residential buildings are concerned, the correct relative order of importance depends on the frames of reference used. Certainly, meteorological perils are more significant than geological hazards. Residential building damage produced by the most important natural hazards is assessed. Governance is shown to be poorly related to actual risk. Tropical cyclone wind-loading codes are amongst the best in the world, but the more limited potential for storm surge damage is largely ignored. While land-use regulations are strong in some states, almost no attention has been paid to appropriate building materials for flood-prone properties. Hail is probably the most important peril along the populated south-eastern seaboard, but no regulations govern roofing materials. Other issues relating to the present understanding of damage to buildings are raised.     

Cardboard as a construction material: a case study

A small cardboard building with a 25-year intended lifetime was developed as a live innovation project to explore and resolve the practical problems surrounding the design, fabrication and construction, costs, and use of an alternative building material. The primary aim to reduce environmental impacts was based on developing the potential of a recycled material as the main structural and cladding component that could be further recycled at the end of its working life. This case study of a small school building presents both the research and development undertaken by the project team and the practical implications of realizing this as a building for a client.     

Indoor environment quality contracts in building projects

The scientific literature is replete with examples that indicate that poor indoor conditions at workplaces reduce work performance and increase short-term sick leave. To address good indoor environment quality (IEQ), strategic and practical design decisions are needed in the early phase of the building process to ensure successful implementation. However, current procurement practices are hampered by fragmentation, long subcontract chains and vague performance requirements. A preliminary study is undertaken that focuses on developing a method of contracting that enables the attainment and verification of the desired IEQ. Using a review of international research and practices, existing commissioning methods and contract procedures are identified for their attention to IEQ. A contract procedure is proposed that fosters agreement on indoor environment between building owners and tenants, and which directs a building project to give users the guarantee of indoor condition. To make a pre-lease contract agreement that includes IEQ, the factors having an influence on the IEQ chain must be included in all building contracts such as those of design, purchase, and operation and maintenance. Thus, the requirements of IEQ require their incorporation into every phase of the building project. The main elements in these contracts, in addition to the requirements of IEQ, are those verifying quality, bonuses and sanctions.

La littérature scientifique est riche en exemples qui montrent que la médiocrité des conditions intérieures sur le lieu de travail réduit les performances opérationnelles et augmente les absences de courte durée pour raisons de santé. Pour obtenir un environnement intérieur de bonne qualité (IEQ), il faut, dès le début du processus de construction, prendre des décisions d'ordre stratégique et pratique en vue d'une mise en ?uvre réussie. Or, la fragmentation, les longues chaînes de contrats de sous-traitance et le manque de précision des impératifs de performance sont autant d'obstacles aux pratiques d'approvisionnement actuelles. Une étude préliminaire est entreprise qui porte, pour l'essentiel, sur le développement d'un mode de réalisation permettant de satisfaire et de vérifier la qualité de l'environnement intérieur recherchée. S'appuyant sur une analyse des pratiques et de la recherche au niveau international, l'auteur recense les méthodes de mise en service et les procédures contractuelles existantes en fonction de l'intérêt porté à l'IEQ. Il est proposé une procédure contractuelle qui encourage les accords en matière d'environnement intérieur entre propriétaires de bâtiments et occupants et qui prescrit un projet de construction offrant aux utilisateurs la garantie d'un environnement intérieur satisfaisant. Pour conclure une convention contractuelle, préalablement au bail de location, qui prévoit l'IEQ, il faut inclure les facteurs ayant une influence sur la chaîne IEQ dans tous les contrats de bâtiments, comme la conception, l'approvisionnement, l'exploitation et la maintenance. Les exigences en matière d'IEQ nécessitent donc qu'elles soient intégrées à toutes les phases d'un projet de bâtiment. Les principaux éléments dans ces contrats, outre les exigences d'IEQ, sont ceux qui vérifient la qualité, les primes et les sanctions.     

Translating Singapore architects' environmental awareness into decision making

Construction activity is known to have a major impact on the environment. Construction is a major consumer of a wide range of naturally occurring and synthesized resources. The extraction, processing and utilization of these resources can have various negative impacts on the environment. With increased awareness and knowledge of these impacts, efforts are being made to avoid these adverse effects. Among these is the selection and specification of appropriate materials. This paper studies the level of environmental awareness and knowledge of architects in Singapore when selecting and specifying materials during the design stage. Responses to a questionnaire indicate that the architects are aware of the environmental impacts of building materials, and knowledgeable about possible measures which could help avoid the problems. However, they are not adopting green design approaches. Key policy directions for government, professional bodies, educators and clients are made to enable Singapore architects to apply their knowledge of environmental issues in their design decisions.     

Architects need environmental feedback

The role of environmental feedback within architects' offices is examined as a fundamental ingredient of sustainability. Three case study buildings are examined using a feedback exercise encompassing the whole building process from early key design decisions to occupation. Results show that sometimes design decisions are taken for aesthetic reasons without certainty on their environmental impact. Improvements are possible especially in energy consumption, glare, the usability of controls, the communication of strategies and comfort conditions. The architects report the feedback lessons relevant for their work. A systematic approach to project feedback is proposed with emphasis in feeding forward to new projects and recording decision-making. To close the information loop, briefs need explicitly to mention performance targets for energy use, management expectations, control requirements and to promote feedback itself.     

Rethinking urban capacity: identifying and appraising vacant buildings

Policies related to urban development and regeneration have prompted a need for greater levels of information concerning vacant land and property. A need is identified to create efficient use (and reuse) of existing real estate. Drawing on information primarily collected for property taxation, a methodology is presented to create comprehensive data sets relating to vacant non-domestic buildings to help identify the type, size and location of long-term vacant property. The case is made for this methodology to be extended and for improved access to comprehensive data to enable scarce real estate resources to be used in a more sustainable manner.     

Construction business system in China: an institutional transformation perspective

During the transformational period from a planned economic system to a market-oriented one, China's construction business system is in an intermediate stage of development. The developing business system has played an increasingly important part in regulating the relations between various actors in the building sector, but the disordered situation in the construction market has fully revealed the shortcomings of the system. Using international experience and practice for reference, China is making efforts to promote the construction business system with Chinese characteristics. The institutional change involves reforms in legislation, property rights, price mechanism and the investment system. The crucial issue lies in deregulation, but this is difficult to realize for a government-led reform. Only if government's control and intervention are decreased enough can the construction market and related professional bodies play their proper roles so that the development platform of China's construction industry can be gradually perfected.     

Dutch performance-based approach to building regulations and public procurement

Along with the publication of the first set of performance-based regulations in 1991, the Netherlands Governmental Building Agency (GBA) introduced innovative performance-based procurement and tendering. A structurally different performance-based regulation document was published in 2001. A continuous research effort paralleled these developments, leading recently to the Policy Document on Building Regulations 2002-06 and the approval of a new national programme called Process and System Innovation in Building (PSIB). Actual and future developments are strongly influenced by the turmoil following the recent disclosure of the wide use of outlawed settlement of calculation cost and project 'rights' by the Dutch contractors. In addition, some blatant cases of fraudulent contract administration were revealed. By the end of 2003, key stakeholders within both the government and industry were in agreement that there was a need for radical change of the economic and social performance of the building and construction sector. The PSIB programme, in combination with a strong deregulation initiative, will be the major driver for the application of the performance approach in the sector.     

Quality and coordination: internationalizing Swedish building research

The structure of Swedish research finance was radically changed in 2001, and the present goals of research policy are that Sweden is to be a leading research nation, where research with a high scientific quality is conducted. However, the process of internationalizing Swedish building research leads to an issue of how international standards for scientific quality are applied and how Swedish researcher participation in industry initiatives and European framework programmes is supported. This issue is discussed against a background of a national system where research funding is indirectly and strongly linked to university teaching, which also means that research institutes are comparatively unimportant. International expansion of large firms in the construction industry has led to an increasing engagement with university research. However, the current process intended to guarantee high scientific quality in projects with national funding is inflexible and not fully compatible with what is required for industry and European research cooperation.