Energising a stylish listed building apartment conversion in Edinburgh

How we overcame challenges for a unique project in Edinburgh.

Programme

When CALA Homes (East) Ltd embarked on the conversion of the former Boroughmuir High School in Edinburgh into high-end apartments, it created a unique opportunity – and some challenges – for us in bringing gas, electricity and water to the site.

The Grade B listed building, designed by renowned architect John Alexander Carfrae, was one of the first buildings in Edinburgh to utilise a steel frame for architecture when it was constructed between 1911 and 1914.

As expected, due to its age, the building did not comply with current regulatory requirements for the installation of gas and electricity supplies needed to support 104 apartments: 87 in the main school building, nine in an annex to the main building and eight new build apartments adjacent to the main building.

This was also a constrained site with limited road access, so our team had to liaise closely with the local authority on road closures to allow for the construction and installation of a new gas network to service the development.

Despite these challenges, CALA’s landmark conversion of one of Edinburgh’s most iconic school buildings is well advanced, with a show home now open onsite. The development offers a collection of one to four-bedroom contemporary apartments.

Outcome

The project involved us bringing gas supply to site by connecting to an existing low-pressure main from an adjacent road, and running electricity cabling to apartments from an electricity substation. When designing the works, we needed to take account of wide variations in site levels and overcome challenges associated with the building’s unique design and listed building status.

Working closely with RSP Consulting Engineers on behalf of CALA Homes (East) Ltd, we embarked on a multi-phase programme of works that included the design and installation of gas and electricity meter banks in the south and north towers and central areas of the building along with the installation of EV charging points. 

The existing substation had the necessary capacity to support the required power for the site, but complex design work was needed to install the utility meter banks, particularly in the central core of the main building. In total, 16 meters were installed in the south tower, 21 in the north tower and 50 in the central core area of the building. The gas meter banks required installation of a bespoke exterior ventilation system because, as the building is listed, holes couldn’t be drilled through the outside walls.

For the gas supply, we connected to the Scotia Gas Networks main grid via two separate low pressure connections: one from the front of the building feeding the central, north tower and annex, and one from the rear of the building for the south tower.

The anticipated completion date for the whole project is May 2022.