Winner 2017

Award for
The Award for Small Projects (of under £1 million)

Project Description

The structure of this mezzanine in a Victorian pump house building is entirely formed with 1.2m x 0.7m cast iron plates that interlock to form both the floor and balustrade. The pieces are sand cast using ductile iron with the pattern modelled in Rhino and CNC cut from timber, due to the repetition cast iron was an efficient and cost effective solution. The form represents the flow of load and stress through the pieces and is optimised for weight and strength while maintaining a very thin depth.

Judge’s comments

The Pump House is a historic workshop constructed in 1903 by the London Hydraulic Power Company. The renovation of the internal space included the addition of a mezzanine floor entirely formed by interlocking 1.2m x 0.7m cast iron panels, bolted together to form both the floor and balustrade.

The Pump House involved ingenious use of cast iron, which has many advantages over steel, as a cheaper raw material that can be cast into endlessly complicated shapes. Working closely with a local foundry and contractor, the engineers used a single mould to cast the panels, reducing manufacturing time and cost.

Project overview

Structural Designer

  • Webb Yates Engineers

Client Name

  • Private


  • London, UK


  • Fabric Space

Principal Contractor

  • Clean Lines Construction

Year Submitted

  • 2017

Submitted By

  • Webb Yates Engineers