An office fit out achieving a 50 per cent reduction in embodied carbon

This was a challenge our project team relished. It took a collaborative and concerted effort between designers, mechanical and electrical engineers, furniture specialists, and commercial, site delivery and environmental teams in partnership with an engaged and passionate client.

A fundamental requirement for the project was that every individual involved needed to adopt a circular way of thinking with a strong focus on reusing existing materials. It was also critical that they all had the right knowledge to make the best environmental decisions.

How we reduced embodied carbon emissions

The plan was straightforward in that this project should actually reduce carbon emissions rather than rely on off-setting schemes. In order to achieve this, we needed to pull many strands together.

Overbury used the tool CarboniCa to assess and report on the carbon impact of the products they selected. By measuring the embodied carbon content, they were able to switch to alternative lower impact materials wherever possible. This provided clear and traceable evidence on the emissions reduction.

The team’s preference for selecting materials and products with Environmental Product Declarations (EPDs) meant that emissions for 23 products were transparent and accurate. The remainder used the RIC’s benchmark data.

Value engineering was an important consideration within the overall fit out process. Decisions were not made solely for financial reasons, but taken alongside the carbon impact.

Reducing onsite waste was essential in lowering carbon emissions and the whole supply chain needed to play its part. We insisted on a waste minimisation plan from every subcontractor and used as many take-back schemes as possible.

Designing for minimal environmental impact

An important design aspect was to reduce the number of internal walls and partitions. Instead we used furniture or folding walls which are more agile and allow for future growth. Where partitions were needed to divide meeting rooms, we selected demountable glass as it’s easy to re-use. A big saving came from retaining and re-integrating over 70 per cent of the ceiling tiles in the new fit out, avoiding 4.6 tonnes of CO2E emissions.

The design only used paint on the walls and EPD comparisons ensured that only those with the lowest embodied carbon were used. We also chose carpets with the lowest embodied carbon whose manufacturers have take-back schemes, and we kept vinyl floor finishes to a minimum. Using timber instead of thin layers of screed and by retaining sections of the raised access flooring for reuse we made significant reductions in emissions.

Originally we had a steel design for the staircase which accounted for 40 per cent of the embodied carbon of the overall project. With the help of CarboniCa, it was redesigned in timber with glass balustrades and limited supporting steel. This reduced the original emissions by 90 per cent and it now contributes less than 5 per cent of the total fit out carbon emissions.

Innovative up-cycling and reupholstering of over 50 per cent of the existing office furniture achieved the desired quality for the project as well as reducing carbon emissions by over 52 per cent.

The final carbon countdown

The aim of ARUP’s Edinburgh project was to achieve a high-quality fit out with a minimal impact from embodied carbon.

The original designs could have resulted in an embodied carbon figure of 89.47 tonnes CO2E Cradle to Gate. However the teams were determined to understand the issues and rigorously apply environmental thinking and methods to the project. Countless marginal and some more significant gains meant the fit out’s embodied carbon was reduced by 49.73%.

ARUP’s new office is a great example of how a determined team can come together and create a winning solution for employees as well as the environment.