Bridging the building performance gap: what is the worst that can happen?

An edited version of the below blog post has also appeared on the Architects' Journal's website here June 10th 2013.

The Architects’ Journal’s ‘Bridge the Gap’ campaign is a timely and highly commendable attempt to mobilise architects and the wider building industry to address the underperformance of so many of our buildings, and what we can – individually and collectively -  do about this.

Many architects seem unaware that large disparities exist between new buildings’ predicted performance and their actual, real performance.(1-3) This means buildings are more costly to operate than predicted, while also having a greater environmental impact than intended.

So far, a variety of reasons have been identified for this performance gap, such as construction errors and the use of inaccurate modelling tools.(4) Additionally, occupant behaviour itself is known to significantly influence energy demand, for instance through how many rooms are heated, thermostat settings and heating duration, opening of windows and how and – whether or not- building systems are at all used or correctly used.(2, 5-10) 
Many low energy buildings increasingly rely on complex building systems, increasing the opportunity for things to ‘go wrong’. 


Clearly, to achieve the ambitious energy reductions required, it is essential that actual energy reductions meet calculated, predicted reductions.(10)

Let’s also be honest: if a building does not perform as (well as) predicted, we tend to hide this news in embarrassed silence. In fact, a bigger problem exists before we even consider this issue: usually architects do not go back and systematically evaluate the buildings they designed to see how they perform once commissioned and occupied. One reason may be that PII providers do not tend to encourage it (“why go back to evaluate your design when you may find problems and get sued”). But as a profession, architects do not seem to be very interested either in finding out their buildings’ performance, nor do they usually get paid to do this.  In fact, most architects probably do not even know what the predicted energy use is of the building they designed (modelling is usually outsourced to other consultants), let alone  what the actual energy use turns out to be. This culture of pre- and post-construction disengagement needs to change  - drastically.

It is long overdue that the building industry as a whole recognises its underperformance. The ‘design-modelling- construction- in-use’ feedback loop is invaluable as it allows us to obtain building and user feedback to reflect on and learn from our mistakes. This learning process – both individually and – if made public - the whole building industry– can then prevent those same mistakes in future building-design and construction.

The addition of an ‘In Use’ workstage in the new RIBA Plan of Work, which “acknowledges the potential benefits of harnessing the project design information to assist with the successful operation and use of a building” (11) is clearly a step in the right direction.  The concern for buildings’ in use performance is also echoed by the Architects’ Journal’s ‘Bridge the Gap‘ campaign.  This campaign aims to support individual and industry-wide reflection and learning, as opposed to the constant pretence that the performance gap does not exist or the constant burying of underperformance under silence.  In so doing, the campaign also raises a crucial question: what is the architect’s and architectural profession’s role and responsibility in bridging this performance gap?

If we stop pretending that the performance gap does not exist, and if we stop burying underperformance under embarrassed silence,  what is the worst that can happen? I believe that we only have to gain: a reflective and reflexive building industry, learning how to build better and predictable buildings for our clients, its users and the environment. 

And, how bad can that really be?

Notes/references

1.                Leaman A, Stevenson F, Bordass B. Building evaluation: practice and principles. Building Research & Information. 2010;38(5):564-77.
2.                Stevenson F, Leaman, A. (editors). Special issue: Housing Occupancy Feedback: linking behaviours and performance. Building Research & Information. 2010;38(5 Sept-Oct 2010).
3.                Mumovic D, Santamouris, M. . A handbook of Sustainable Building Design & Engineering. An Integrated Approach to energy, health and operational performance. London: Earthscan; 2009.
4.                LeedsMet. AIRTIGHTNESS OF UK HOUSING. LeedsMet; 2009 [cited 2012 April 10th]; Available from: http://www.leedsmet.ac.uk/teaching/vsite/low_carbon_housing/airtightness/housing/index.htm.
5.                Barrett M LR, Oreszczyn T,Steadman P. How to support growrh with less energy. 2006.
6.                Audenaert A, Briffaerts K, Engels L. Practical versus theoretical domestic energy consumption for space heating. Energy Policy. 2011;39(9):5219-27.
7.                Guerra Santin O, Itard, L., Visscher, H. The effect of occupancy and building characteristics on energy use for space and water heating in Dutch residential stock. Energy and Buildings. 2009;41(11):1223-32.
8.                Guerra-Santin O, Itard, L. Occupants' behaviour: determinants and effects on residential heating consumption. Building Research & Information. 2010;38(3):318-38.
9.                Guerra Santin O. Behavioural Patterns and User Profiles related to energy consumption for heating. Energy and Buildings. 2011;43(10):2662-72.
10.              Summerfield A, Oreszcyn, T., Pathan, A., Hong, S. . Occupant Behaviour and energy use. In: Mumovic D, Santamouris, M., editor. A handbook of Sustainable Building Design & Engineering An Integrated Approach to energy, health and operational performance. London: Earthscan; 2009.
11.              RIBA. RIBA 2013 Plan of Work 2013; Available from: http://www.ribaplanofwork.com/PlanOfWork.aspx.