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Adjusting to new green realities: retrofit not new build – the new Ska Rating Environmental Assessment Scheme

By Brian Edwards

It is self evident that the future lies in making better use of the existing stock of buildings rather than investing in new. This is the message behind Chris Huhne’s ‘Green Deal’ and part of the hidden agenda of the Big Society. The powerful corporate players in the past that helped pioneer sustainable office design, such as the banks (Barclays), insurance companies (SwissRe) and utility companies (Wessex Water) are no longer in a position to innovate. Finance is subject to tight control with spending refocused on to existing buildings. The challenge is to make the building stock more carbon efficient and in the process to use adapted built capital as the basis for the UK’s economic recovery.

In principle this is a sensible tactic and even one based upon sound ecological practice. In nature there is evolution not revolution and species adapt in order to survive. If buildings and even whole cities were species they would be in a state of perpetual adaptation as they responded to environmental change. Demolition does not occur in nature and neither does waste – everything is evolving with redundant parts recycled through the biological or chemical chain. The Green Deal offers many benefits and job opportunities, especially with its planned extension from homes to businesses.

Nearly 18% of UK carbon emissions are attributed to non domestic buildings. Energy retrofit is an obvious first step to making the building stock more suitable for the low carbon future. The government plans on investing £90bn over 5 years in improving the UK building stock. So the architectural profession should applaud the recent government announcement in these stringent times. However, the tools available and most of the skill base in architecture (particularly sustainable architecture) is invested in the design of new buildings. The trusted environmental assessment methods such as BREEAM, LEED, Code for Sustainable Homes (CSH) and PassivHaus have their basis in new construction not retrofit.

Aware of the problem, there has been the growth recently in the modification of existing assessment tools aimed at refurbishment. They use much the same methodology and bring the same level of business confidence (and marketing) from new build to existing structures. However, although BREEAM and LEED can be adapted to existing buildings and BREEAM has a dedicated version for domestic refurbishment, the introduction of the RICS’s Ska Rating is the first aimed specifically at non-domestic retrofit.

The new Ska Rating is a significant and timely innovation. Like other environmental assessment tools it owes a great deal to BREEAM. The Ska Rating is based upon an assessment template covering seven topics supported by documented and tested standards, and undertaken by trained assessors. Like BREEAM and LEED it costs money for formal accreditation and certification, but the Ska Rating is also designed for more informal self assessment. As such, Ska is useful to architects as a more casual assessment tool during the various stages of a retrofit project.

As with new construction, the use of environmental assessment tools for refurbishment should be prescribed in the project brief (with extra costs accounted for). Undertaking assessment late in the process often raises problems and involves extra costs and maybe client disappointment. Also it is worth being aware that the client wants certification to provide added financial value whilst to the architect the use of such tools allows a project’s environmental credential to be measured at different stages. Such measurement can be set against best practice standards which in the Ska Rating is made available free of charge as part of an online assessment tool.

As with LEED and BREEAM, the formal Ska Rating accreditation achieved is graded, here into gold, silver or bronze. This has the benefit of benchmarking schemes allowing for the sustainability performance of different retrofit projects to be compared against key criteria. These are ‘energy and CO₂, waste, water, pollution, well-being, materials and transport’ with the addition of other topics according to the nature of the project. Linking together ‘energy and CO₂’ is a step forward since energy increasingly comes from renewable sources, meaning that energy is not always the problem but carbon emissions are. Also Ska allows for the embodied energy of materials and construction to be considered under the ‘material’ section and cross referenced to energy profiling of the project as a whole.

The Ska Rating fills a gap in the tools available to help architects achieve sustainability in refurbishment projects. It is well pitched in terms of market realities and by providing a largely free self assessment path, the Ska Rating removes some of the cost and inflexibility inherent in existing environmental assessment schemes. In theory the rating scheme could apply to any type of retrofit project (including schools, hotels and hospitals) although weightings would need to be adjusted.

In this age of austerity we need tools which are generic as well as building type specific. Launched last year, the Ska Rating has received a number of industry awards for excellence and leadership in sustainability.

Professor Brian Edwards teaches and researches at the Royal Danish Academy of Fine Arts, school of Architecture, in Copenhagen and serves on the RIBA Sustainable Futures Group. He is the author of the Rough Guide to Sustainability, Green Buildings Pay and (with David Turrent) Sustainable Housing.