The UK’s Better Buildings Partnership (BPP) has published details of the vital elements that have contributed to the success of the hugely transformational Australian NABERS scheme.
Its Design for Performance project has also published details of a pilot program and a road map necessary for the governance structures, market demand and industry skills to deliver a design-for-performance (DfP) approach in the UK.
Eleven more developers including Derwent London and Stanhope have also now joined this nascent British version of the NABERS scheme, which addresses the performance gap between the theoretical design and the actual results from allegedly energy efficient offices.
The BPP says that critical success factors of the design-for-performance approach are setting energy performance targets at project inception, embedding these within the supply chain for delivery, and verifying performance when the building is occupied.
According to Sarah Ratcliffe, the chief executive of the Better Buildings Partnership, the reason efforts to introduce NABERS in the UK have failed in the past is that the regulation to achieve the outcomes is not working.
“Voluntary efforts are never checked to see whether the intent delivers the promised performance,” she says. “Data on actual operational performance is not easily obtainable to ensure appropriate accountability, and is therefore invisible to the market, especially investors and occupiers”.
Australia has had NABERS since 1999. It now covers 86 per cent of the office market and has helped to improve the energy intensity of landlord services by 36 per cent since 2010.
There are clear market benefits, Ratcliffe says. “It has always been a mystery to me why performance in any other industry is measured by outcomes and yet in the real estate sector we seem satisfied to equate performance with intent. This approach is no longer fit for purpose.”
The BPP’s study has taken three years to find out the seven key elements of its success.
- an operational performance targets and rating system
- a clear definition of what constitutes base building energy (used for landlord-supplied services)
- advanced simulation software modelling
- independent design reviews
- intensive commissioning and fine tuning
- highly skilled practitioners
- strong market drivers.
The project will now embark on a new phase to develop a rating scheme with the associated rules, tools and quality assurance processes, and identify market pioneers willing to develop this approach.
It will also be looking at finding training partners to help upskill the industry, and appoint a scheme administrator with a responsibility to oversee and administer the scheme in the UK.
Existing members of the scheme include: DfP Pioneers Grosvenor Britain & Ireland, Great Portland Estates, Landsec, Legal & General, Lendlease, Nuveen Real Estate and The Crown Estate. They were all piloting the new design-for-performance approach on at least one of their new office developments.
More engineering firms have also signed up: AECOM, Arup, Atkins, Built Physics, BuroHappold Engineering, Cundall, Hoare Lea, KJ Tait, Ramboll, TFT and Watkins Payne. They have said that they will advocate DfP to their clients.
How Australia has led the way
In Australia, a post-construction NABERS Energy Base Building rating covers 12 months of data once the building is over three quarters occupied, to validate the achieved operational performance.
By focusing on performance outcome instead of prescriptive design requirements, NABERS has fostered an industry that embraces innovation and is continually pushing the boundaries of base building energy use.
It has stimulated market demand, facilitated progressive policy development and ultimately, delivered better buildings for occupiers and investors, says the report.
The benefit for developers and property owners is an excellent performance standard for the construction of new offices. For investors and lenders its benefit is that the buildings created this way result in higher incomes for them. Green bond issuers can also give robust assurances of returns on investment and carbon savings.
Occupiers benefit from reduced utility costs and the knowledge that the building they are using will live up to its promises.
Building designers and contractors can demonstrate they have skills and experience to deliver such buildings and even property and facility managers find such buildings easier to manage.
A UK scheme will also benefit government targets for reducing carbon emissions.
It’s now commonplace for base building performance targets to be included within contractual arrangements for new office developments. The building industry in Australia routinely delivers against a NABERS Energy 4.5 star target or higher.
Keys to success: Australia versus the UK
Australia: The detailed simulation of heating, ventilation and air conditioning (HVAC) systems in a building has been vital in Australia to test against a range of expected operational conditions. It ensures that plant and systems are correctly sized for the demands placed upon them. This benefit outweighs the additional cost of the modelling.
UK: Does not have the skills to do this yet.
Australia: HVAC modellers enjoy a high status in the design team.
UK: Training will be needed as well as an increase in the level of priority given to modelling.
Australia: Independent design reviews of the actual performance of completed buildings mean that, according to anecdotal feedback from practitioners, their greatest impact has been to educate and upskill the industry by placing a large amount of design advice in front of the design team, which helps to inform the next project.
UK: To replicate this will require a culture change.
Australia: Following the handover of a building to its tenants, a comprehensive fine-tuning program starts that can last for up to two years, partly depending upon how long it takes to reach full occupancy. It ensures that the building reaches its optimum performance.
UK: This almost never happens, and again, will require a culture change.
Australia: It took at least five years for the skillset to be introduced to enable the potential of NABERS to be realised.
UK: The same should be expected, with the carrot dangling in front of the industry being, as in Australia, a competitive market with a large pool of skilled practitioners for developers to choose from.
Australia: The role of government was also important. Australian government agencies were behind it and were major occupiers of such buildings, meaning that commercial property owners had no choice but to rate their properties. Over time, demand strengthened, with other occupiers setting targets and property owners attempting to out-perform each other. The 2010 Building Energy Efficiency Disclosure Act in 2010 encouraged the wider office market by setting the legal requirement for all offices over 2,000 m2 to have a NABERS rating for sale or letting.
UK: The BPP is arguing for a similar requirement.
Pilot study results
Six office developments have piloted this approach in the UK. Three of these reached the final measurement and verification and operational rating stages. They are owned by British Land, Transport for London and the Crown Estate.
There have been seven results from this pilot:
- It’s vital to separate out the energy consumption that the property owner is responsible for (that is, base building), from that which the occupier is responsible for (that is, lighting and IT equipment).
- Sub-metering is necessary to achieve this result which will require changes in UK guidance.
- Simulation modelling software that is up to the job needs to be standardised and mainstreamed
- Technologies usually deployed in the UK are different from those in Australia, and this will require a culture change. Examples include the use of fixed speed pumps, fan coils, fixed chilled hot water supply temperatures for airconditioning, and a lack of independent controls for individual zones within buildings.
- The lack of transparency for operational performance of UK buildings masks management inefficiencies that result in buildings not achieving their full potential. Independent design reviews would reveal this.
- Highly skilled fine-tuning of building controls in the first two years identifies faults that prevent the building from operating in court in accordance with the modelled design intent.
- There is a significant skills gap in the UK for HVAC uncontrolled simulation and post-occupancy fine tuning.
The BPP says a NABERS type scheme is therefore desperately needed in the UK and is calling for an independent committee and a scheme administrator to set it up.
David Thorpe is the author of the books The ‘One Planet’ Life and the new ‘One Planet’ Cities. From October he is teaching an online Post-Graduate Certificate in “One Planet” Governance.