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.     

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.     

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.     

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.     

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.     

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.     

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.     

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.     

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.     

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.     

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.     

Evolution of energy policy in the Netherlands: past, present and future

In this paper, the past, present and possible future developments of energy policy for the built environment in the Netherlands are described briefly. The focus is on the development of and necessity for introducing new policy instruments for the built environment. Over the years, energy policy has evolved gradually to create a more integrated approach to the energy efficiency of buildings and larger urban districts. However, further evolution might be inevitable due to a shift of the primary driver for 'energy' policy from energy conservation to carbon dioxide reduction. Maximum targets of carbon dioxide emissions are being developed for each sector by 2010 and each sector has the obligation to meet its defined carbon dioxide reduction goal. Severe carbon dioxide reduction goals for the built environment in the Netherlands can only be achieved by means of energy efficiency improvement and fuel substitution, replacing natural gas with lower-carbon fuels. The introduction of lower-carbon fuels raises policy questions on whether to maintain the old infrastructure at great cost or whether investment should be in a new energy infrastructure and how this transition can be managed.     

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.     

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.     

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.     

Developments in tubular daylight guidance systems

Tubular daylight guidance systems are linear devices that channel daylight into the core of a building. They consist of a light transport section with, at the outer end, some device for capturing natural light and, at the inner end, a means of distributing the light within the interior. This technology is examined in terms of performance, cost, design issues and governance (codes) for the different generic types of systems. Gaps in the knowledge on a range of issues, particularly operational human factors, are identified as key determinants delaying the wider implementation of this technology.     

Managing and interpreting uncertainty for climate change risk

Climate change is a significant risk for the built environment because it implies not only warmer weather, but also more extreme weather events, such as storms, droughts and heat waves. Considerable uncertainty about the future also exists, partly because of the response of society's apparent reluctance to mitigate climate change by reducing fossil fuel consumption. An adaptive response to the challenge draws on the literature on climate change, the urban environment, natural hazards and risk analysis. Two concepts - life cycle costs and the avoidance of ruin - provide a useful framework for factoring the uncertainty associated with climate change into a risk analysis for the built environment. Monitoring, prediction, data management and communication are the unglamorous underpinnings of a successful urban risk-management strategy. For cities to develop a significantly improved response capacity, the active support of senior levels of government is essential because cities have neither the legal powers nor the resources to tackle climate change on their own. Ultimately, the biggest challenges are institutional and behavioural.     

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.     

Changes to building research funding in Sweden

Changes to the Swedish research landscape since 2001 are described including the re-organization of research councils, research programmes, the management and allocation of public funding research in Sweden, and the effects on built environment research. The reasons for these changes include the desire for increased integration with European Union research programmes, an increasing emphasis on inter- and multidisciplinary research, and the desire for research to contribute to economic well-being. Despite Sweden's high level of government investment in research, shifting priorities and an increasing number of applicants have resulted in reduced allocations for built environment research. This presents the challenging tasks to define and maintain core research capabilities within the built environment sector as well as to ensure adequate industry engagement with both the creation of the research agenda and the use of research outputs.