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Architects ‘liable for energy performance’


Architects must take the initative on post-occupancy evaluation or suffer the consequences, writes Laura Mark

Industry figures are warning architects they will become liable for buildings that fail to meet energy performance targets.

Sarah Cary, British Land’s sustainable development executive has said architects have their ‘head in the sand’ and must grasp the implications of energy performance on liability and include post-occupancy evaluation (POE) in their scope of work.

Speaking at the ‘Mind the Gap’ breakfast, part of Open City’s Green Sky Thinking programme, where the AJ launched its ‘Bridge the Gap’ campaign, Cary added: ‘Gone are the days when you are not responsible for the performance for the building two years after occupancy.’

Patrick Walls, from small practice SOUP Architects, added: ‘The client will want to maintain liability to someone if the projected running costs differentiate significantly. Proving liability and its effect to building contracts will become inevitable with duty of care.’

But Simon Allford warned that concerns over liability could stall research into building performance. He said: ‘Who is legally liable to whom, and for what, is a much more complex subject to debate. I hope the potential liabilities do not once again result in money for research and innovation being diverted into fending off unreasonable appointment documents and buildings designed and  benchmarked to the lowest possible common denominator.’

Architectural technologist Kell Jones also warned about the dangers of introducing building performance into contracts. He said: ‘By effectively underwriting the performance of the building post occupancy, architects are taking on risks which should be borne elsewhere. Attempts to make this risk contractual will open a can of worms.’

At the breakfast, hosted at the offices of Feilden Clegg Bradley Studios (FCBS), Cary also spoke of the ‘gaping hole’ in predicted and actual building performance. She added: ‘If [closing the gap] was easy, architects would have done it already.’

Co-speaker Ian Taylor of FCBS also described how the performance gap was exacerbated by a lack of knowledge surrounding the topic. He said: ‘The understanding of how energy is used is often missing’, pointing to problems with metering and its effective use.

Allford agrees: ‘Performance is most greatly affected by a lack of understanding of often overly complex buildings.’

According to Roderic Bunn, a building performance analyst, procurement methods and construction standards are to blame. He said: ‘The performance gap is a consequence – a symptom of a deep malaise in modern construction procurement that seeks to obtain cost savings by fragmenting, via a proliferation of subcontracts, what used to be a relatively seamless process in traditional procurement.

‘That fragmentation leads to credibility gaps between professional and contract packages, through which the initial good intentions plummet.’

Tom Dollard, head of sustainability at Pollard Thomas Edwards Architects agrees. He said: ‘The performance gap will be addressed through re-structuring the procurement of buildings.’

Ian McChesney added: ‘Most lapses in performance tend to be due to poor construction standards. Any tightening of standards must be good for architects who have been marginalised by Design and Build-style procurement processes. If standards are tightened, contractors will be forced to heed the advice of architects on issues of quality – so quality and architecture win out.’

EPR Architects’ Dieter Gockman urged architects to drive forward the wider adoption of post-occupancy. He said: ‘Architects need to take the lead on the sustainable agenda and wrest control back from service engineers and specialist consultants.

‘There is a danger that architects are seen as part of the problem rather than part of the solution. If we are not careful, another facet of architectural service will be hived off to specialist consultants, further undermining our position and ability to lead the design team.’

Architype is one practice already leading the field in post-occupancy. ‘Enlightened clients are already buying into it and are willing to pay for post occupancy monitoring and evaluation,’ said the practice’s Jon Ackroyd. ‘Building User Surveys (BUS) cost about £1,000 and take about two days’ work. A thermal imaging camera costs between £1,000 and £5,000. Our office owns one and it has proved a very useful tool in showing us where there might be issues in a building.’

He added: ‘A reserve of about 1 per cent should be built into the project costs for this kind of monitoring. We add approximately 0.6 per cent to our fee for this service.’

Meanwhile a growing number of experts are calling for improved education in the area of post-occupancy and especially for more people able to interpret and understand the data.

Jones said: ‘There is a shortfall in the number and quality of people who can interpret the data that is coming out of POEs. There is an emerging market for people who understand data and buildings. 

‘Companies which are serious about filling the performance gap need to start to looking to employ people who understand the science and have good data analysis skills.’

Aedas sustainability director Judit Kimpian said professional bodies needed to encourage awareness and education in post-occupancy evaluation: ‘Professional bodies should recognise this way of working as a new standard.’ And future head of Sheffield University Fionn Stevenson called for ‘more joined-up thinking between CIBSE and RIBA’ and that post-occupancy should be embedded in architectural education. ‘The culture has to start at RIBA Part 1 and 2,’ Stevenson said.



Alan Shingler, partner at Sheppard Robson and chair of Sustainable Futures at RIBA

Architects ignore at your peril the actual performance compared the design performance of buildings, but we must also appreciate the difficulties in linking designed energy performance which make certain assumptions regarding the building occupation & how the building is actually used by the tenant. Hence the fundamental difference between EPC’s & DEC’s. The architect is often not appointed or able to gain the necessary data from the end user client.

Few architects would decline an appointment that includes POE & monitoring but this work is rarely embraced by the client & often only undertaken if financed by the practice, through TSB funded work & academic research. I hope the RIBA’s new plan of work will be the catalysts for change in architect’s appointments. This includes 2 separately identified work stages for ‘Handover’ & ‘In Use’ therefore providing a platform for architects to undertake these services and once appointed we must ensure this knowledge is shared with the project team, closing the loop back into the briefing stage & shared with industry on web platforms like Carbon Buzz.

Judit Kimpian, director of sustainable architecture and research at Aedas

There is a growing evidence base that current legislation is not achieving the expected reductions in the actual energy use of buildings and, if anything, can have significant unintended consequences. Large portfolio holders in particular are becoming aware of the commercial risks associated with the Performance Gap as high EPC ratings have been shown to bear little relationship to operational energy use.

At the root of the problem is that to comply with building regulations designers only need to assess a building’s energy consumption potential. This is done using calculations that are not rooted in statistical evidence but evaluate designs under idealised operating circumstances, without ‘value engineering’, rushed contractors, poorly trained building managers or unpredictable occupiers.

What makes matters worse is that the current legislative framework rewards complexity in both systems and controls even though these were shown to present a major risk to operational energy use decades ago already (Bordass, el al). In the on-going TSB BPE programme most building users struggle with Building Management Systems (BMS), which affect maintenance costs and in many cases occupant comfort and productivity. While technological solutions offer a great potential, smart buildings need smart clients, designers, contractors and even smarter end users.

The issue of the performance gap is so fundamental that the RIBA Sustainable Futures Group campaigns for the ‘disclosure’ of data and lessons learned via the RIBA|CIBSE crowdsourcing platform CarbonBuzz and the RIBA Awards have for the first time included energy consumption data as part of the evaluation criteria.

The SFG wants to go further – it aims to incorporate Soft Landings and the feedback from buildings in operation in the RIBA Plan of Works so that architects can verify that investment in energy efficiency measures have brought about the expected benefits. What a revelation that will be…

Savvier clients, whose business models are based on the whole life cost of their estate, are setting measured energy use targets instead of opting for BREEAM or other sustainability ratings, which still rely on compliance metrics to plan for low-energy operation.

Many architects, including Aedas, Feilden Clegg Bradley, Sheppard Robson, Architype and Bere architects view the focus on operational energy use as an opportunity – after all designs that take into account long term occupancy patterns and adaptability are bound to be more robust and resilient to changes in climate and demographics. These practices argue that in their traditional role of ‘integrators’ architects are perfectly placed to balance the long-term needs of occupants, investors and the broader urban context.

Can architects be sued if a building consumes a lot of energy in use? That seems unlikely for now. However new procurement models targeting operational energy use are emerging, which will reward those with a track record in achieving better value for their clients. With post occupancy evaluations soon to be incorporated into the procurement of all public projects the benefits of low energy and maintenance costs as well as happier occupants are going to become more pronounced, which is bound to make a compelling case for closing the performance gap.

Festus Moffat, director of John Robertson Architects

There is currently a misunderstanding with regard to EPCs being some sort of prediction tool for energy performance, whereas they are, in fact, largely a Part L compliance tool. Results vary wildly depending on the level of software used to calculate the EPC so it should be no surprise that this is not reflected in the actual performance or DEC.  I think it unlikely however that the architecture and fabric performance are the main reasons for the discrepancy between the two measures.

Much better energy in use prediction tools are needed and British Land, for who we recently completed the refurbishment of 199 Bishopsgate, has again been leading the way in this by developing models that will explain to tenants before they enter into a lease the likely level of their energy bills. 

Jerry Tate, principal of Jerry Tate Architects

If architects took ownership of building performance this would be a massive positive for the profession in the long term. The performance gap often comes from badly designed calculation methods (like SAP although it is improving) and poor on site workmanship, to counter this we really need better publicly available post-occupancy data for precedents. In the US they are putting together a national database of building performance which will be incredibly useful for that region.

Peter Morris of Peter Morris Architect

Part of the problem seems to be that the architectural profession considers such surveys are below them, so up springs new consultancy companies which adds costs to the client and lacks continuity. Predicted Energy Surveys should be consider at the start of the design process. Very often they are carried out at the end of the project and are very generic. Architects need to show they can do this work, rather than lose out to other consultants. 

Another problem is we need more post occupation surveys carried out to build up a better understanding of the problems some buildings might encounter, unfortunately this is expensive and not considered a necessity by many clients. How does the Architectural Education system deal with such topics? They don’t. Our universities should be leading the field in post occupancy surveys. 

During a recession I would not encourage financial penalties, or more regulations, but I would prefer to see more encouragement, to make it a more desirable aspiration for society. Maybe a letter of ‘well done’ from Michael Gove. Or name and shaming in the national press - an energy performance league.

Ivan Redi of Ortlos

British Land is very commercial developer with lot of resources. For such companies the check of achieved performance after few years should be mandatory. But for smaller architectural studios it is not easy not only because of scope and scale of their work, but because the actual performance is dependable on many factors beyond the design – here are the building contractors and others involved in realization process more responsible then an architect. The suggestion would put unnecessary additional pressure on smaller studios which are already overwhelmed by too many requirements. This sounds like unfair PR by bigger companies increasing pressure on the smaller ones under cover of energy efficiency. So in my opinion the contractors and buildings companies are those who are liable in this case.

Alfred Munkenbeck of Munkenbeck+Partners Architects

There is no way to measure actual performance in residential buildings as long as you provide openable doors and windows.  An open window loses far more heat than any insulated wall or roof… If people can open their windows, they will.  The government should back off a bit on new homes and concern themselves with leaky existing ones.  

Endlessly ramping up new building performance has gone beyond the point of diminishing returns in a mild climate such as the UK.  Remember, it is so warm here that few people had central heating at all before the 1960’s… a jumper was considered adequate.  

Alan Crawford of Crawford Partnership

I attended a CPD seminar last night on CE Marking for construction products, which is another European standard that will regulate quality of materials specified in projects. The point being that as architects we make every endeavour to keep up to date with regulations and policies that govern both the design and construction of any project.

As architects we are always striving to attain the highest standards of design and construction, and these often need to be balanced against client budgetary aspirations, but not in the sacrifice of mandatory building regulations standards.

Energy performance gaps can only be monitored by comparative analysis between predictive energy performance and actual ‘in use’ data feedback, which is often not readily available, however, even on a domestic scale, energy monitoring systems are becoming much more readily available, as could be seen at the recent ECObuild Exhibition. The majority of architects already work with environmental design engineers to obtain design input to ensure highest standards of energy performance can be achieved, but this again comes at an additional price for the client in an already expensive pre construction process.

Not sure therefore why the ‘buck’ should stop with the architect in this debate!

Anna Surgenor of UK-GBC

As energy prices go up and tenants increasingly look to understand future costs associated with tenanted space, they will start to ask what the actual predicted energy is likely to be for that space.

Proactive landlords who are leading in sustainability are starting to communicate this information and this will raise the bar for future tenanted space as we start to make energy performance more visible for existing commercial buildings.

Architects are in a key position to influence building performance at the design stage and communicate the benefits to clients and future tenants.

The benefits of POE need to be communicated to clients and tenants – particularly those around energy and cost savings but also more generally about the benefits it will bring to reducing future void periods and lease-ability.

We need leading organisations to make their actual energy performance visible and clear so that customers can start to compare options. The rest of the industry will then follow. Future European legislation may also play its part.

Getting landlords and tenants to communicate it will help and, in turn, encouraging tenants to demand this from their landlords. We need to develop a robust DECs methodology which provides accurate benchmarks and get Government to regulate the display of actual performance of a building, not the predicted or partial performance of the building with no people using it. It’s very important especially as buildings offer the biggest cost effective carbon abatement opportunity. There are huge energy savings to be had by very small investment.

Sarah Lewis of bere:architects
When it comes to bridging the performance gap we invest a lot of time with the contractors we work with to provide training in air tightness and cold bridging techniques and we work closely with the M&E sub-contractors to ensure the systems are all installed, insulated and commissioned correctly.  In addition we feel it is very important to disseminate our monitoring and performance results and to this end we regularly participate in or hold events to share our findings and experiences.

As architects we feel that monitoring is an essential part of evaluating our completed projects and learning what elements are working well, where any issues are arising and how we can further improve our buildings in the future. Our monitoring is also part of our soft-landings approach which we adopt on all of our projects, in soft-landings you spend time post completion with the building occupants to help make sure they are getting the most out of the building and to help fine tune any areas which are not performing optimally.  This process helps to prevent any small issues with the building escalating into major problems for the building occupants which, if left unchecked, could affect not only the buildings performance but its success at meeting the expectations and needs of the users.  Finally, as Passive House architects we feel lucky to have the PHPP which is the tool Passive House designers use to design Passive House’s and very accurately predict the final energy demand of the buildings. The PHPP has a proven track record for accuracy and has lived up to this reputation with all of our completed and monitored Passive House projects to date.

John Christophers, Associated Architects
There are a number of things we need to do to bridge the energy performance gap.

Of course there is a baseline to bring all building design and construction into line with best practice over issues like airtightness, thermal bridging, etc.  After a few zero carbon buildings, we have found that tiny details like the cold bridging of a lock cylinder or the second line airtightness sealing at a window hinge really do make a difference – we need to get obsessive to get these things right. Fabric first: every stitch of it.

Then there is the issue that any predictive model of building occupation and environment can only be an approximation. So as we begin to understand more clearly their margin of error,  the ‘gap’ should reduce.

Then there are controls.  It would be great if we made buildings with environmental control as intuitive as riding a bicycle: it happens almost without you being aware of it.  Part of this is about designers understanding the mindsets of different users at different times of day and year and simplifying a sometimes bewildering array of control options.  The psychology of acceptable comfort levels varies hugely.

All these factors should add up to a more sophisticated understanding of how very low energy buildings - and how human beings - perform, and therefore reduce the gap. 

Andrew Goodman of Good Architecture

Both designers and construction workforce need to increase their understanding of construction detailing to ensure construction achieves design performance. Building Regulations needs to ditch current carbon compliance methodologies and adopt energy modelling methodologies with proven, accurate prediction of building preformance, e.g PHPP. Make it a requirement of Building Regulations to verify/ demonstrate that construction work has been carried out in accordance with design.

Fran Bradshaw, Anne Thorne Architects:

Bridge the energy performance gap;-  go for  Passivhaus! Use PHPP, choose your design and construct team carefully, soft landings, work closely with building occupiers, commission correctly, monitor and adjust if necessary. Energy use;- remember people are all different, and don’t preach. Make it easy to be economical (see above). Good building management reaching design team as well as the other way round!

 Kirsten Henson, director of KLH Sustainability

How do we bridge the building energy performance gap?

  1. Design assumptions must reflect in-use performance of buildings.
  2. Include unregulated loads in modelling and compliance regulations.
  3. More accurate modelling of system controls
  4. To use Integrated building technologies with control strategies
  5. Use of smart metering to monitor energy usage
  6. Communicating the design intent on-site and during post occupancy (soft-landings)
  7. Better designer/client communication
  8. Better understanding of occupant behaviour
  9. Considering variations in occupancy hours.

What needs to be done to make sure actual energy usage of buildings lives up to design expectations?

  1. Regular monitoring and feedback – included within design teams initial design proposals and fees.  As an expensive add-on it is never likely to be done, there must be a business interest for designers to commit to this level of understanding of building performance.
  2. Ensure conscious use of the building by occupants – SIMPLE building user guides, not sections of the Operational Manual reconfigured as a Building  User Manual
  3. Education and training on the operation of the building for the occupants and facility management team.  Ensure all new users and changes to FM teams are addressed
  4. Provide prospective occupiers with a clearer indication of the likely range of energy use, carbon dioxide emissions and costs of running their new building.
  5. Better control & management of services
  6. Comprehensive use of BIM to ensure future upgrades and refurbs do not impact building performance.








Readers' comments (3)

  • Kevan Shaw

    As a lighting Design practice KSLD have been proactive in seeking Post Occupancy Evaluation specifically for lighting aspects and human performance and satisfaction rather than focussing on energy use alone. We have come up against brick walls with building owners just not prepared to have their new schemes assessed. There is also a massive reluctance for building owners or occupiers to pay for Post Occupancy Evaluation. Given the current state of the market and downward pressure on fees this is a significant piece of work if it is to be meaningful and cannot be funded by design practices out of their revenue.

    In respect of our work we have several instances where our carefully considered designs and control schemes have been defeated by building occupants and facilities management organisations through laziness or demanding unnecessary lighting levels and times switched on. Once a building and its services are handed over it is unrealistic for the design team to bear full liability for performance, this has to be directed towards the operators.

    Post Occupancy Evaluation is a vital part of the design process. This is the feedback that helps us improve and learn from design. Relying as we do now on anecdotal evidence for the most part is not really adequate. On energy issues we are forced to incorporate lots of separate energy monitoring and metering but there seems to be a major lack of incentive for the data available from these to be properly collected and analysed.

    Kevan Shaw C.Eng, MILP

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  • BPE is about improving DESIGN ittself (not just the design process) as well as performance - we must never forget that. Too often we focus on the outcomes rather than the underlying usability issues when we talk about BPE. The above dialogue rarely mentions the word design improvement in connection with performance illustrating the massive cognitive disconnect we still have in the industry, which begins with our initial training in schools of architecture. RIBA need to take a lead here and seriously investigate how we can bring teaching of BPE into RIBA validation criteria, so that it is not looked down as 'something that engineers do after we build the building'. Apologies to all those already converted, but there are a huge number out there who do not believe POE has serious benefits for design - really!

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  • Spending money on Post Occupancy reviews of projects built under current building practices is like closing the door after the horse has bolted? Take a look at the DEC data for over 40,000 public buildings if you want to see just how badly our buildings are performing http://www.cse.org.uk/pages/
    resources/opendata#display_energy_certificate_data . The problem with Building Regulation compliant buildings and any of the environmental assessments you care to choose is that they do not do much for the energy performance of the building. They are solely focused on CO2 and reward the use of renewables so that on paper you can offset poorly performing buildings by the use of bio-mass, PVs, etc. etc. It is not just about construction quality but also how we design, attention to thermal bridging, air quality, air tightness, orientation and form factor (i.e. building physics). The methodology is already out there it's called Passivhaus and using the PHPP delivers extermely accurate energy predictions.

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