Knowledge of how our buildings work is crucial to creating better architecture. Without feedback loops informing architects of the performance of their designs, most buildings become prototypes, and the knowledge that could be gained from each building is lost. This is particularly important today as designers of “sustainable” buildings using new and innovative strategies, technologies and systems need to know how effectively these reduce environmental impact while meeting the needs of users and creating comfortable spaces. Yet the sad fact is that historically, few architects have made an effort to get routine feedback on how well their designs perform and meet the needs of occupants, or how successful their design strategies have been. Architects hand over one job (often less profitable than anticipated) and the next project beckons. The users are left to struggle with the completed building, and an opportunity to learn from the project is lost!
In How Buildings Learn, Stewart Brand talks about “blue jeans buildings”–buildings that age honestly and elegantly over time.1 This requires acceptance of buildings as evolving entities where the design and construction phases represent just the start of a long process over the life of the building. A strategy is needed particularly for the first years of occupancy to ensure a smooth transition from construction to operation, and to ensure that the necessary information is available for future change and evolution of the building as needs evolve. Just as important, the strategy should ensure that the designers and contractors get the necessary feedback on the performance of the building so that they can learn the lessons of the project for future benefit. Without this, designers will continue to repeat the same mistakes from the past due to a lack of knowledge about how their buildings function. Sir Andrew Derbyshire has argued that “…the architect who believes that his work is done as soon as the building is finished must be made to look as ridiculous as the scientist who believes that his experiment is complete as soon as he has assembled the apparatus.”2
Post-occupancy evaluation
Post-occupancy evaluation (POE) has been defined as “examination of the effectiveness for human users of occupied design environments”3 and can provide design teams with valuable feedback about their designs. POEs range in complexity from an informal walk-through with some observation and discussion with users, to complex studies involving experts and the use of a variety of survey tools measuring energy, water use and indoor air quality. There is great potential for POEs to act as a design aid with a range of benefits over different timescales. Problems identified during a POE can often be overcome or alleviated by immediate minor modifications and repairs, thereby improving performance and the occupant experience. Users can help identify where problems occur focusing more detailed investigation on the relevant areas of concern. In the medium term, designers and repeat clients can use knowledge gained from one project to improve subsequent projects. Finally, in the longer term, POEs can be used to improve guidance, benchmarking and design education, benefitting design processes and procurement programs.
As a management tool, POEs can address questions related to how a building contributes to business aims, such as efficiency of operation, satisfaction of staff, and productivity. The past decade has seen a growing recognition within business that the physical workplace can provide a platform for organizational change and business innovation. Research has established significant links between the workplace environment, job satisfaction, worker productivity, and thus the corporate bottom line. As a result, a primary driver for POEs in recent years has been to identify whether organizational and workplace goals have been achieved. Some large organizations have implemented feedback systems to improve building function and sometimes to provide information when a building is to be renovated. However, such POE research usually focuses on business goals rather than design feedback. It is also rarely made publicly available and often does not involve the building designer so there is little benefit to the design process. Some design consultancies are now establishing their own feedback mechanisms, but these are usually kept private for reasons of confidentiality and concerns about liability. However, a few initiatives have been made public and provide valuable lessons for the industry.
Probe
The Probe studies4 in the UK were a unique collaboration between researchers, designers, government and a publisher to undertake and publish POE studies of 16 commercial and institutional buildings. They addressed the efficient operation of buildings, generating valuable information about the success or otherwise of a variety of green building strategies, and how users cope with poorly performing buildings (see www.usablebuildings.co.uk for details).
The Probe studies identified some of the strategic lessons that are relevant to all architects, including:
* Clear strategic objectives should be established for the design team, and design proposals should be regularly reviewed against these objectives and the needs of occupants.
* More careful programming and assessment of options and solutions for usability, robustness and manageability is needed.
* Simple designs carried out well are more likely to work–avoid unnecessary complications and pay attention to detail.
* Local user overrides for control systems are important.
* The equivalent of “sea trials” may be needed for complex buildings.
* Don’t procure what you cannot manage–appropriate building management structures are crucial.
* Air leakage derails many servicing strategies.
* There is a need for collaboration and data sharing–in the design team and industry.
Building performance assessment should be an essential part of education.
One of the key findings of the Probe studies was that building managers often do not understand the level of complexity and are unable to manage buildings effectively. Figure 1 illustrates the appropriateness of different design approaches for matching levels of technical complexity with appropriate building management input. The figure suggests that technically complex buildings need more management input to function efficiently and effectively (Type A). Many buildings fall into the trap of being technically complex, and management assumes this means that the building looks after itself and thus provides no additional resources (Type C). Technically simple buildings are more appropriate when building management input is likely to be limited (Type B) but this may be difficult in large projects. This is relevant to design teams when forming initial design strategies for a project, and clients should be aware of the implications of decisions.
The Canadian Context
In Canada, Keen Engineering carried out POE surveys of seven “green” buildings in the Pacific Northwest using a web-based Occupant Satisfaction Survey developed by the Center for the Built Environment (CBE) at the University of California at Berkeley. This covers thermal comfort, indoor air quality, acoustic quality, visual privacy, lighting quality and aspects such as furniture. Some of the key lessons about the technologies used in green buildings include:5
* Energy consumption was consistently lower in the green buildings studied–16% to 55% in energy costs were saved compared to similar British Columbia buildings.
* Occupants preferred the indoor air quality in the green buildings compared to the benchmark group of buildings, presumably reflecting the advantag
es of natural ventilation.
* Occupant satisfaction with lighting was consistently as high, or higher than the benchmark group of buildings.
* More education about green building features may increase occupant satisfaction.
* Even in well-designed buildings, energy consumption depends on how the building is used and managed.
* Specific terms of tenant/owner lease agreements can impact energy consumption.
Next Steps
Both the above studies confirm that where buildings work well, it is often due to good communications within the design team, leading to thoughtful solutions implemented and followed through with attention to detail. It is time architects recognized the importance of feedback and the potential benefits for designers of engaging the supply side and providing better follow-through and customer service. In the UK, the RIBA Practice Committee has recently begun this process of addressing feedback by agreeing to introduce a new stage into the RIBA Plan of Work. In this age when we need to address issues of sustainability and building durability, we also need to remember the role of users in the process of achieving a successful building.
Mark Gorgolewski is a professor in Ryerson University’s Department of Architectural Science.
1 Brand, Stewart. How Buildings Learn: What Happens After They Are Built. Viking: New York, 1994.
2 Derbyshire, Andrew. “Architecture, Science and Feedback” from the Closing the Loop Conference. Windsor, UK, 2004.
3 Zimmerman, A. and M. Martin. “Post-occupancy Evaluation: Benefits and Barriers” in Building Research & Information, Vol. 29, No. 2, 2001.
4 Bordass, R., R. Bunn, R. Cohen, and A. Leaman. “The Probe Project: Technical Lessons From Probe 2” from the CIBSE National Conference. UK, 1999.
5 Hydes, K. et al. “Understanding Our Green Buildings: Seven POEs in British Columbia” from the Closing the Loop Conference. Windsor, UK, 2004.