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Fit-out environmental assessment tool: SkaNovember 2011

The sustainability of fit-out projects can be assessed using the Ska benchmarking and environmental assessment tool. Sarah Birchall explains how it works.

The origin of Ska goes back to 2005, when the developer Skansen set up a research project with the Royal Institution of Chartered Surveyors (RICS) and consultant AECOM to measure the environmental effects of an office fit-out.

The RICS recognised that tools such as BREEAM/LEED are too large and complex for fit-out projects, and in any case only consider the characteristics of the base building. A system designed purely to assess retrofits led to the Ska method.

Example of how the scoring works in Ska

Ska, a simple abbreviation of Skansen, provides a means of assessing the refurbishment of existing buildings to ensure the retrofit is carried out in an environmentally considerate way. The process is different to that of other environmental assessment methods, such as BREEAM or LEED, as it solely focuses on the fit-out.

"We're calling Ska a second generation environmental assessment method as we learnt from the previous generation of methodologies and changed some fundamental principles" said AECOM's David Cheshire. "For example, the whole assessment is on-line from initial review through to obtaining the electronic certificate. It's free to access and use, with only a £50 fee for certification, and it can be started and completed very quickly and simply to match the short timescales of a fit-out project."

One of the key features of Ska is its flexibility. The assessment topics depend on the nature of the retrofit, as opposed to a rating system where the categories are fixed, and where non-compliance with any particular criterion would automatically generate a negative score.

Ska therefore enables a design team to select the topics that are relevant and which they are able to influence through product selection or improvement of a process.

Ska was initially developed to specifically measure and compare the environmental performance of UK fit-outs. Recent developments have increased the scope of Ska, allowing it to be used for pilot projects of other building types and projects, and also outside of the UK. While this is restricted to informal assessments, future development will lead to certification.

Tailored versions of Ska are being planned. For example, Ska's development team is developing Ska Retail to satisfy demand from the retail sector.

Ska's inner workings

Ska has been designed with three assessment stages: design, handover and occupancy. Although assessment can be carried out on all stages, only the handover and occupancy stage assessments can be formally certified.

Introducing Ska early in a project is key to a sustainable fit-out. The design stage assessment is also important, as fit-out contractors cannot be expected to implement environmentally suitable solutions if these are not included as part of the design.

Ska covers 104 good practice measures. A good practice measure is defined as "a single element of the fit-out process that represents best practice from an environmental perspective." The good practice measures are categorised into eight sustainability issues, including energy use and carbon dioxide emissions, water, waste, materials, pollution, well-being, transport, and other.

The first step in assessing a project is the scoping stage. The assessor will sit down with the design team and establish what the particular fit-out will involve. Only the elements identified will be included in the assessment. This flexible scoping also allows for changes throughout the project.

For the assessment to take place there must be at least 20 measures in scope. From experience the RICS has found that 50-60 good practice measures will be in scope for the average fit-out.

Ska ranks the environmental effect of each good practice measure differently by giving each measure a ranking (from 1-104) relative to the other existing measures. A ranking of one has the largest environmental benefit, and a score of 104 the lowest benefit. Threshold measures are the number of good practice measures that have to be achieved for a particular target rating.

The system also uses a concept known as gateway measures. The gateway measures are aimed at ensuring that a high rating cannot be achieved without carrying out the most effective measures. It also prevents the teams from getting a good score by just targeting the easiest measures. This is designed to incentivise people to install things that will have the greatest benefit.

There are currently three rating thresholds that can be achieved: Bronze, Silver, and Gold. These are reached by achieving 25 per cent, 50 per cent and 75 per cent respectively. Anything less than 25 per cent will not be rated. An achieved rating will depend on:

  • the number of measures that were in scope (threshold measures)
  • the number of top-ranking measures achieved (the gateway measures).

To obtain a Gold Ska rating, 75 of these must be achieved. In addition to this, any 12 out of the top 15 ranked measures (from the gateway pool) within the scope of the project must also be achieved for a Gold Ska rating to be awarded.

A rating can only be published after a formal assessment by a RICS accredited assessor.

Those who are familiar with other environmental assessment methods such as BREEAM and LEED will find Ska very familiar and intuitive. Each good practice measure has an individual data sheet including detail of the criteria, scoping, and detail to help judge whether a measure has been achieved and the rationale behind the measure and guidance.

Where next

As of May 2011 there were 1216 users of the Ska tool, 126 certified assessors, 193 assessment projects and eight certified assessments.

The RICS and AECOM have set up a training programme whereby assessors can be trained and accredited. This currently involves a two-day training course followed by an exam.

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