Windsor House

Demolition and rebuild on a constrained site

Based near beautiful Green Park in Central London, a new build steel framed commercial office building development providing 24,000 square feet of office space with a new double basement.

On St James’s Street in SW1A, this development included demolishing the original building, and erecting a new one which included a new double basement level; adjacent to a London Underground interchange tunnel and several roads.

Walsh worked closely with the contractors Galliford Try to devise an efficient buildable solution using a steel frame structure. The tight central London site had significant constraints including the existing basement substation that had to remain live until a new facility had been constructed on the site.

We were also tasked with developing this area into a double basement. This required Approval In Principle (AIP) and several further approvals such as Party Wall Awards, three separate roads and a London Underground tunnel.

During the project it became apparent that the required lettable area in the basements was constrained by a variety of boundary conditions. To solve these challenges without compromising the plans, we worked closely with Galliford Try’s temporary works engineers and successfully achieved everything in the original plans without delay.

  • Lothbury Investment Management
  • EPR
  • Galliford Try
Completion Date2015
  • London
  • Westminster

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Taking Sustainability Seriously

Sustainability is in our DNA and we have our own ambitious goals to achieve Net Zero as a business and with our designs. With innovative in-house monitoring tools, Walsh clients have seen on average reductions of 10-20% total embodied carbon, with some of our flagship work achieving 60-70% reductions compared with baseline figures.