Realising the Potential of Post-occupancy Evaluations

Post Occupancy Evaluation (POE), is the study of how a building performs (in terms of functionality, resource consumption, comfort etc…) and why it performs that way:

• Was it due to the design?
• The way it was constructed or commissioned?
• Are the users able to manage it efficiently?

The aim is to collect detailed performance data (for at least 1 – 3 years of operation following handover) and feedback from users and present it in a useable format. Data and information should then be fed back to designers and project teams to identify lessons learned to promote improved design and construction in the future. The ultimate aim is to identify any areas of improvement and provide solutions that, in turn, enhance a building’s energy efficiency, increase user satisfaction and reduce operating costs. This is increasingly becoming a requirement on construction projects, especially where the client has adopted the soft landings framework.

As reported in an article in the Public Sector Build Journal, POE can also be a hugely informative and effective tool for public sector sites and social housing developments, helping to ensure buildings perform as they are designed to and helping to justify and validate how the public purse is being spent.

A case study in the RIBA Post Occupancy Evaluation: an essential tool for the built environment Report, highlighted  how POE can make buildings greener. Assessing the performance of 188 homes across the UK, research by Innovate UK, revealed that despite all homes being “low energy” and 50 certified Passivhaus, many of the homes were losing heat at the windows and doors. The POE used a range of fabric thermal performance tests and infrared thermal imaging to highlight where the problems were occurring. The tests exposed that there was a need for improved detailing, specification and workmanship. This highlighted that whilst there is the intention of producing “low energy” homes this is not always how the home operates in reality. Without undertaking the study, the homeowners would not understand how much energy their home uses compared to the intention. The POE highlighted the issues to be rectified, and as a result the energy consumption of the buildings was reduced.

This is a great example of a POE identifying systems that are not delivering what they were designed to do. The systems may look good on paper in terms of delivering low energy homes but the reality is if the windows and doors aren’t installed correctly then they will never achieve the low energy results intended. It highlighted the issues to be rectified, and as a result the energy consumption of the buildings was reduced.

Around 80% of environmental impacts are determined by decisions taken at the design stage and a consequence of those decisions can be both waste and pollution.  Design, therefore, plays a crucial role in minimising the environmental impacts (and consequently the costs) of the whole life-cycle of a project from its construction through its operation to the end of its life. For more guidance on Design and other Construction Environmental topics take a look at the CIP Construction Environmental Manual.  Free trials available.