For nearly three years stone and conservation specialists Stonewest have been working on the renovation of the Church of St Martin-in-the-Fields off Trafalgar Square in London (see "return of the white church' below). As part of the project Stonewest also carried out repairs and renovation to the John Nash North Range, which houses the vicarage, church offices and The Connection at St Martin’s, which helps homeless people.

The work here also included a new roof using Heather Blue slate tiles from Welsh//Slate’s Penrhyn Quarry and Blue Grey slates from the company’s Ffestiniog Quarry, installed by roofing contractors NDM. The roof has been built up on a metal frame using existing trusses and close boarding. This approach has allowed the roof to be insulated and provides a ventilation chamber behind the slates to create a diffusion zone.