Many well-designed buildings fail to live up to their environmental credentials when the tenants move in. Richenda Wilson reports on reducing the gap
Few buildings perform as efficiently and effectively as they are designed to. And not just by an inconsequential margin; often by a factor of two or three when it comes to energy use.
In fact, the “greenest” buildings on paper tend to be the biggest disappointments in practice, according to Roderic Bunn, building performance analyst at BSRIA – the Building Services Research and Information Association. “In theory you can design a low-energy building, but in reality they are anything but,” he says.
Added complications
Bunn worked with Adrian Leaman and Bill Bordass in the 1990s on the PROBE studies, which examined occupied buildings to see how well they were functioning. The research found there had been too little improvement over the years – despite the increasing urgency brought about by greater awareness of climate change and resource depletion.
Technological fixes have proliferated since the PROBE studies, but many of these have served to make buildings more complicated and more challenging to run efficiently. “Unmanageable complication is the enemy of good performance,” says Bordass. “Many of the cures are worse than the disease and have just created new problems.”
Bordass and Leaman later helped to set up the Usable Buildings Trust (usablebuildings.co.uk), which aims to bring “honest information about building performance into the public domain”, says Leaman. They find that many new buildings disappoint, not only in energy terms but also have higher than expected running costs and disappointing levels of occupant satisfaction.
One reason why energy use often differs so widely from predicted figures is that compliance calculations look only at fixed building services, assessing energy used by regulated sources, including heating, cooling, ventilation and lighting. However, they need not account for likely consumption from appliances plugged into sockets or from any IT – although admittedly this is harder to predict. If a building contains a data centre, for example, electricity bills can be high.
Consider VillageGreen, furniture maker Herman Miller’s new open plan, naturally ventilated head office in Chippenham, the design of which was rated excellent by the BREEAM building assessment scheme. But when a BSRIA energy assessor visited two years after the building opened, he found it was using twice as much electricity as recommended in the ECON19 good practice benchmark for that type of office building. The discrepancy is largely due to VillageGreen’s data centre and permanently lit showroom.
On display
Display energy certificates (DECs), which have been compulsory for large public buildings in the UK since 2008, are designed to promote the improvement of the energy performance of buildings, and increase transparency about efficiency.
“The DEC is a good tool because it takes into account real energy consumption rather than theoretical performance,” says Katharine Deas, managing director of Low Carbon Workplace. “However, it is limited in that the occupancy of the building is only partly considered in the calculations, meaning that sparsely occupied buildings often perform better.”
More realistic predictions will help to reduce the gap between anticipated and actual performance, giving a truer picture of whether the building is functioning as it should. This clearly offers advantages to design professionals and building users, but other factors can militate against this. For example, when planning authorities stipulate a requirement to produce a certain proportion of energy from renewables, it can disincentivise project teams from producing higher forecasts of energy consumption.
Architecture practice Aedas is working with RIBA and CIBSE on Carbon Buzz (carbonbuzz.org), an initiative that aims to provide a reliable platform to exchange information about predicted versus real energy use. It encourages building professionals to take more account of unregulated loads to make more accurate predictions and then to report back on how buildings are doing to share best practice.
Evaluating performance
Building performance evaluation (BPE), also known as post-occupancy evaluation (POE), is the key to establishing whether buildings are working as they should. BSRIA suggests evaluations should contain the following three elements:
- a forensic walkthrough – an inspection to check the building’s operation and identify whether there are any emerging problems or wasteful operational practices;
- an energy survey – a breakdown of the energy used in a building by type of consumption, such as heating, air conditioning, lighting; and
- an assessment of occupant satisfaction – surveys and interviews of building users and occupiers.
BPE can be very illuminating. Bordass says they often find building controls are poor and tuned incorrectly; design intent is seldom communicated well to users and managers, implicitly or explicitly; and the interfaces to control systems are poor.
“Operators and occupiers are not properly informed to take advantage of the design of the base build,” agrees Deas. “Also, skills gaps in the technical building management community mean that complex, low-carbon buildings are often without sufficiently skilled operatives.”
Bordass believes a large part of the problem is that everybody – designers, builders, clients and the government – tend to see handover as the end of the process, rather than the beginning of the building’s life.
“Handover and walk-away is systemically embedded in standard procedures and contracts, so follow-through and feedback are not part of the standard offering. We need to close the feedback loop between construction, property owners and users,” he explains.
He says good intentions can fall by the wayside during design development, construction and commissioning for a myriad of reasons. There may be changes in client requirements, fabric or services, for example, or substitutions, problems with build quality or delays.
After completion, there may be fit-out changes and clashes, no fine-tuning or training, unintended outcomes, undetected waste, control problems, poor user interfaces and unexpected night loads, all causing a lot of avoidable waste.
Most problems stem from the fact that there are gaps between responsibilities, and there is not enough communication between developers, engineers, landlords and tenants. “It’s not an architectural problem, an engineering problem, a management problem or a client problem,” says Leaman. “It’s all of these things.
“Evaluation has been resisted by the architectural profession rather than embraced,” he adds. “They say they are interested, but it’s rare for them to go back into a building and study it.”
“People often don’t want to talk about this and they don’t want inconvenient problems,” says Jon Ackroyd at architectural practice Architype, which implements BPE on numerous projects. “But if we’re really serious about driving down energy consumption then we need to be going back in and understanding those buildings. There are a lot of really interesting lessons to be learned, no matter how uncomfortable they might be.
“Historically people have been reluctant to share, but organisations are getting much better at partnering.”
However, it is often difficult to determine exactly whose liability it is when problems arise, says Ackroyd. “Project professional indemnity is already a reality on larger projects. It covers a project rather than individual companies having their own insurance, so you don’t sue each other and are more likely to share responsibility. I do think that at least a basic level of BPE should become mandatory – it’s an important tool to ensure we achieve the goals we’re setting.”
The Usable Buildings Trust is less enthusiastic about making such initiatives compulsory, believing that legislation often encourages people to do the minimum they need to in order to comply with regulations.
A new professionalism
Bordass suggests the industry as a whole needs a new professionalism. Many construction-related institutions already require their members to understand and practise sustainable development. As part of this, the building professional’s role needs to be redefined to engage with outcomes.
“We need to make much more immediate and effective links between research, practice and policymaking,” he says. “And we need a learning curve, not a blaming curve.”
The trust is a prime mover behind “soft landings”, an initiative now championed by BSRIA. It aims to help designers and builders to engage with outcomes and to follow through for three years beyond practical completion, ensuring that occupiers understand how to best use their building to improve operational performance and to provide valuable feedback to project teams. It dovetails with energy performance certification, building logbooks, green leases and corporate social responsibility.
The five-stage programme starts with encouraging constructive dialogue between the designer, constructor and client at the inception stage. Stage two brings together the project team to review comparable projects and detail how the building will work for managers and users. As buildings often evolve during design, the soft landings team can anticipate this and consider how to respond to the client’s calls for adaptations.
During stage three (pre-handover), the initiative enables operators to spend more time understanding interfaces and systems before occupation. In stage four (initial aftercare), there is continuing involvement by the client, design and building team to explore lessons learned and occupant satisfaction in the critical early months of occupation. The fifth stage involves extended after-care and POE for three years after occupation.
The costs for the early stages are relatively insignificant and extra work during the three-year aftercare period should pay for itself by adding value to the building, reducing rework and lowering energy bills.
Soft landings needs high-level support from all partners associated with the project and works best if there is a champion assigned to the project throughout. Its aim is not to apportion blame for defects, but neither does it advocate offering financial incentives for success.
As BSRIA explains: “Soft landings is about identifying things that cannot be classified as defects and which may, in any case, lurk just below the radar of defects and snagging teams – such as shortfalls in performance, in controllability, in manageability and in dealing with unintended consequences of system operation. Quite often, all that’s needed are clear explanations and better user guidance.”
In practice
Hampshire County Council has been using the principles enshrined in soft landings for many years. When the council refurbished Elizabeth II Court in Winchester, it stripped back the 1960s concrete office block to its core and created a building that uses half the energy of its predecessor, while housing almost double the number of staff.
“We were involved with the design team and the Carbon Trust from early feasibility studies through design and execution on site,” explains Steve Hall, senior engineering manager at the council, adding that energy use is on target after a bit of fine-tuning.
User satisfaction is a major part of the project for him: “It was very important to keep everyone involved. It is not the occupiers’ day job to run and manage the building, but they need to know who to go to discuss issues about the building and the new flexible working arrangements. There’s no point having a building that’s energy efficient if everyone inside is grumbling. It’s important to keep on top of the trivial issues that can become major irritants.”
Phase one of the project was seen as a learning phase to inform decisions about phase two – and other refurbishment and building projects in Hampshire.
Architects Architype used the principles of soft landings at the Willows campus, an educational facility in Wolverhampton, working closely with the users, including primary headteacher Sue Vaughan.
She says that BPE has helped to identify technical issues, such as freezers overheating through inadequate ventilation, as well as informative user-focused activities, including a set of posters to encourage staff and pupils to reduce energy use. Two years after occupation, Vaughan says: “We are still having termly meetings and still picking up issues.”
Ackroyd at Architype adds: “The way procurement works doesn’t always lend itself to using BPE or soft landings. With the economic downturn, there is a lot of pressure to reduce costs. It all depends on how enlightened the procurer is and whether they appreciate that, ultimately, it will save them money.
“Such approaches help architects to learn from our projects and we are finding it gives us a competitive edge when bidding for new work.”
