BUILT ENVIRONMENT JOURNAL

Designing energy efficient offices

A pioneering UK scheme is following Australia's example by encouraging buildings that are designed for performance

Author: Sarah Ratcliffe

01 February 2020

The rising tide of concern about climate change is difficult to ignore, whether it is investors divesting from fossil fuel assets, the UK government's commitment to zero carbon, or the sustained effort of organisations such as Extinction Rebellion.

A swathe of commitments by built environment leaders and professional bodies acknowledges the important role that buildings play in mitigating and preparing for climate change. Better Buildings Partnership (BBP) launched its own climate commitment in September with 23 member signatories covering more than £300bn of assets under management.

This commitment acknowledged the scientific imperative to provide net zero carbon buildings by 2050, and to support this effort signatories will be publishing their net zero carbon pathways in 2020. But as the commitments and headlines ebb and flow, it is critical to put into place the mechanisms that will transform the efficiency of our new and existing buildings.

Problems and precedents

BBP, a UK-based collaboration of commercial property owners, has been working for more than a decade to help its members improve the energy performance of their property portfolios.

Although these efforts have helped to highlight and support industry leadership, they have been significantly hampered by a number of important issues.

  • The regulations intended to achieve energy efficiency are failing – they secure energy efficiency in theory but not in practice. Data collected by BBP for its Real Estate Environmental Benchmark suggests there is no correlation between how efficiently an office building uses energy and its energy performance certificate rating.
  • Existing voluntary schemes such as BREEAM examine design intent, but rarely check or verify whether this leads to buildings that perform better.
  • Data on actual operational performance is not easy to obtain, or delineated in a way that ensures appropriate accountability for performance and promotes improvement.
  • Operational performance is not reported either and is therefore invisible to the market, especially investors and occupiers.

This lack of focus on the performance of assets and the UK culture of designing for compliance has led to the well-known gap between designed and in-use performance.

NABERS

Quite rightly, the role of mandatory and voluntary certification schemes as tools to encourage energy efficiency has come under continuing scrutiny. BBP therefore began to look outside the UK for examples of schemes that have successfully transformed the market, and one that we found was the National Australian Built Environment Rating System (NABERS).

Introduced in 1998, NABERS helped to cultivate Australia's culture of designing for performance. The voluntary operational rating scheme benchmarked the energy used by a landlord to service an office building, referred to as a base building rating, and used a simple star scale with six being the best and one the lowest.

As a result of its success and voluntary take-up by the real-estate market, the Australian government introduced the Building Energy Efficiency Disclosure Act in 2010. This legislation made it a legal requirement for all commercial office buildings with a net lettable area of more than 2,000m2 to obtain and disclose a valid NABERS Energy base building or whole building rating at the point of sale or lease.

In 2017, the threshold was lowered to 1,000m2. Now covering 86% of the office sector by floor area, it has transformed the energy performance of such buildings. Since the introduction of the 2010 Act, the average energy intensity of all base building-rated offices has improved by 36%, with the average star rating increasing from 3.3 to 4.4.

Although initially focusing on existing buildings, NABERS has also changed the design approach to new office buildings and major refurbishments through the development of an energy commitment agreement. Established in 2002, this provides a framework for property owners and developers that commits their design teams and contractors to design and construct a new or refurbished office building that achieves a targeted base building rating.

Put simply, Australia has learnt to build or refurbish office buildings of a much better standard than those in the UK, thanks to the transparency of NABERS and the market benefits it brings. There are other schemes that focus on performance in use, such as the US Energy Star, but NABERS differentiates itself on the grounds that the base building rating enables clear accountability for energy use in a building, addressing the perennial challenge of split incentives and landlord and occupier responsibilities.

DfP in the UK

The Design for Performance (DfP) initiative, launched in 2015 and supported by BBP, therefore set out to discover whether NABERS could be replicated in the UK. The industry-funded project involving a range of stakeholders sought to understand the development and application of NABERS in the Australian real-estate market, identifying the elements of the scheme and its commitment agreement framework that have contributed to its success.

An initial feasibility study was followed by an 18-month pilot programme, to test which factors were key to the success of the rating and agreement framework in actual UK developments. The aim was to provide a sound evidence base that would inform how a scheme could be effectively implemented.

A summary report of the research, Design for Performance: A new approach to delivering energy efficient offices in the UK, was published in June and identified seven factors essential to success:

  • an operational performance target and rating system
  • a clear base building definition
  • advanced simulation
  • independent design reviews
  • intensive commissioning and fine tuning
  • highly skilled practitioners
  • strong market drivers.

Accelerated progress

The report concluded that not only is it possible to design for performance in the UK, but that such an approach is desperately needed if the industry is to fulfil the government’s climate change ambitions. Having initiated significant demand for a DfP approach in the UK, the project's executive board gave the go-ahead for BBP to lead the next phase.

Over the past year, progress has accelerated, passing a number of milestones.

  • A memorandum of understanding has been signed between NABERS and BBP so the UK can access to the Australian scheme's infrastructure, tools, guidance and expertise to help develop its programme.
  • Nine major UK office developers have signed up as DfP pioneers, undertaking to include this on at least one project in their respective development pipelines.
  • Eleven partners have committed to advocating DfP to their clients and training them to implement it.
  • DfP principles have been integrated into industry standards including the British Council for Offices’ Guide to Specification 2019, RIBA's Plan of Work sustainability overlay and the BREEAM UK New Construction Update 2018.

DfP has also attracted interest from an advocacy and policy perspective, with BPP's research supporting many recent recommendations on UK commercial buildings' efficiency and the development of green finance services. This critical work should give the government evidence to apply DfP in other sectors, where supportive policies will be vital.

"Not only is it possible to design for performance in the UK, but such an approach is desperately needed if the industry is to fulfil the government's climate change ambitions"

sratcliffe@betterbuildingspartnership.co.uk

Related competencies include: Sustainability

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