Leroy House,
London N1

Projects / Leroy House

A multi‑phase redevelopment delivering refurbishment, rooftop extension and new‑build works at Leroy House.

Location London N1
Client Workspace Group
PQS/Employers Agent Stace LLP
Architect Piercy & Co
Structural Engineer Heyne Tillett Steel
M&E Engineer Hoara Lea

Key Features

Key Features

  • BREEAM Excellent multi‑phase redevelopment
  • Lightweight single‑storey rooftop extension
  • New 4–5 storey reinforced concrete western extension
  • Enabling works including demolition and substructure interventions
  • Targeted structural strengthening to existing frames and cores
  • Mechanical and electrical services upgrade throughout

This innovative BREEAM “Excellent” project transformed the Leroy House site with a bold, multi-phase development. We added a sleek single-storey rooftop extension on top the existing building, while also constructing a modern, new extension at the western end of the site, where a former car park once stood.

Our work began with a comprehensive enabling phase; clearing out old structures, carrying out partial demolitions, and implementing crucial substructure works. We also modernized Leroy House’s interior, upgrading all mechanical and electrical services, as well as replacing the glazing throughout, including windows, doors and terraces on the 3rd and 4th floors.

To minimise the load on the existing foundations, the rooftop extension was designed with a lightweight steel frame and timber joisted infill, while steel braced frames extended the building’s cores. Strengthening works were carefully executed on upper-floor transfer beams and columns, ensuring the integrity of the structure without extensive modifications to the substructure.

The western extension brought something entirely new: a 4-5 storey, reinforced concrete building, designed as an independent structure. Supported by a robust new concrete lift core and shear walls, this addition added a striking new dimension to the Leroy House site.