UK Energy and Industry Minister Kwasi Kwarteng

The super-successful building operational energy performance rating scheme pioneered in Australia has launched in the UK following 18 months of detailed trials to adapt it to the UK environment.

“A unique opportunity to build back better”

At the launch event, Business, Energy and Industry Minister Kwasi Kwarteng called it “a unique opportunity to build back better” and said that “reducing emissions is a key priority in the government’s commitment to net zero emissions by 2050”.

NABERS measures the energy efficiency, water usage, waste management and indoor environment quality of a building or tenancy and its impact on the environment.

The rating scheme for existing buildings will help building owners to accurately target, measure and communicate the energy performance of their buildings, demonstrate whether offices are on a net zero carbon trajectory, and provide investors and occupiers with the confidence that the buildings they own and occupy are aligned with their climate change ambitions.

Kwarteng said that applying NABERS to the commercial real estate sector is vital. “I hope that the approach can be adopted by the market, increasing transparency to drive efficiency so that investors and occupants can understand and increase their awareness.”

A Design for Performance process will target the design stage of a new office development or refurbishment.

There has been intense cooperation between the UK and Australia leading to this point. 

“We can’t solve climate change without working together. This shows what successful international collaboration looks like,” said Kwarteng.

The UK’s Better Buildings Partnership, which has led this initiative, has coordinated 25 firms representing £300 billion (AUD$544.4 billion) a year of investments to pilot NABERS UK.

Sarah Ratcliffe, BBP’s CEO, said the program would contribute significant evidence of UK action on climate change leading up to COP26, which the country is hosting in November next year (postponed from this year due to the pandemic).

The performance gap – the ratio between the actual energy use and that which was modelled at the design stage – in commercial buildings in the UK. Astonishingly, no buildings achieve their predicted energy consumption level

“Nobody knows how commercial buildings perform in use. The performance gap exists but we have had no idea how to address it,” Ratcliffe said. “The market needs performance measurement based on outcomes if we are truly to understand how. At the moment they blame each other for poor performance and so we have had stalemate on action. NABERS will end that stalemate. 

“The method requires a rigorous approach to boundaries and verification. Accountability is critical. Building energy performance is dependent on both the owners and occupiers. It has transformed the market in Australia but we had to prove that it would work here.”

Unlike in Australia, NABERS will be confined to commercial office buildings with two schemes, one for existing and one for new buildings.

Performance will be rated on 12 months’ operational data.

Star rating system

Christopher Botten, program manager at Better Buildings Partnership, described the six performance levels. “The Australian rating scale launched with 3 stars being average performance for the office building stock. NABERS UK has been calibrated so 3 stars is average for the current UK commercial office stock. 

“A 3 star Australian building and a 3 star UK building are comparable in the sense that the rating scale has been developed based on data from each geography. Offices in Australia have improved so much over time that the average for the office stock is approximately 4.5 stars now,” Botten said.

He said the star ratings “are based on normalised consumption by floor area of the office, climate and hours of use so they can actually be compared”.

He added that 14 projects are now going through the designed for performance process, and “it’s encouraging we are aware of at least ten more wanting to sign up”.

The base building data came from 200 buildings and the BREEAM dataset for new building benchmarks, and is adapted to HVAC configurations and the design process following independent feedback from a review panel of practitioners, steered by Verco and DeltaQ.

The scheme will be administered by BRE, who will coordinate assessor training (expressions of interest welcome).

The Australian experience

Carlos Flores, director of NABERS (Australia), said “[w]e are involved because although we are 17,000 km away, climate change is global. A recent study of new buildings in the UK showed no building achieved their designed performance once in operations, and some were up to 10 times as bad as they were supposed to be. This is not rare. The gap between design and performance varies from sector to sector but it’s not unique to any country.

“In Australia over the past 20 years, 90 per cent of buildings who have undertaken a NABERS Commitment Agreement have met their energy target in operation.”

He described the difference between the two products on offer. “Design for performance of new buildings brings many of the same ingredients to the UK. We’ve had feedback from experience and independent designers in the same sector contributing views into the scheme’s design process.”

Over 15 years the Australia Square building has improved from zero to 5 stars.

The average rate of improvement of NABERS certified buildings in Australia.

Over the last 20 years, Government leasing and especially the introduction of the requirement for disclosure of performance have driven continual efficiency improvements.

“And the value of buildings has improved because the buildings have much longer leases and lower levels of vacancies. It’s given more confidence to investors. We even have forty portfolios now participating in the Sustainable Portfolios Index 2020, where all of the competitors show where they are on the way to net zero.”

How good performance improves the value of buildings, longer leases and fewer vacancies.

“We need to do this over the whole planet,” concluded Flores.

Australia’s sustainable portfolio index 2020: the top 10 of 40 portfolios. This publicly available information shows how well each portfolio is performing

The full team

Shamir Ghumra, head of building performance services at BRE, said the building science centre was “very excited to be partnering with NABERS to make a transformational impact on the energy efficiency of offices”.

Abigail Dean from Nuveen, Nils Rage from Landsec, Peter Williams from Stanhope and Simon Leckie from Lendlease echoed their excitement and enthusiasm to partake in the scheme, with Rage commenting on how good it was to test design details.

“It’s really important to allow the market to do its job in a way that it hasn’t been able to do so far,” said Dean.

The work has been funded by British Land; Derwent London; Federated Hermes / MEPC; Great Portland Estates; Grosvenor Britain & Ireland; Landsec; Legal & General Investment Management; Lendlease; Nuveen Real Estate; Royal London Asset Management and Stanhope, and backed by industry bodies including the British Council for Offices; British Property Federation; BRE; BSRIA; CIBSE; CREFC Europe; RIBA; RICS; UKGBC and the Usable Buildings Trust. 

The scheme was developed for the UK market with expert input from Verco & DeltaQ.

The government consultation on energy performance disclosure for commercial buildings is expected before the end of the year.

David Thorpe is the author of Passive Solar Architecture Pocket Reference, Energy Management in Buildings and Sustainable Home Refurbishment. He lives in the UK.

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