Soho Theatre Walthamstow, London

Project Overview

Background

In 2019, the London Borough of Waltham Forest purchased the former MGM / EMD / Granada Cinema, a Grade II listed building on Hoe Street in London. Its plan was to convert the premises into an attractive new 960-seater venue suitable for modern audiences and a range of live performances.

Originally built in the 1930s and known by many names over the ensuing years, the site would be the subject of a £30m refurbishment scheme. This would see the creation of a modern, multi-purpose entertainment venue, to be known as the Soho Theatre Walthamstow. Its owners planned to retain many of its historic architectural features, including the main stage and foyer, but the building would also benefit from a new media suite, modern seating, three new bar areas, a café and new studio spaces.

The building’s façades would also be enhanced, and part of that work would include the installation of an external wall insulation system.

Brief

Energy efficiency and sustainability were important considerations for this project. On the roofs, solar PV panels would be fitted. The iconic front façade would be left largely unchanged but, elsewhere, an EWI system based on non-combustible mineral fibre insulation would be installed. The architect chose a mineral fibre system in order to achieve the highest standards of fire safety in what was expected to be a busy and popular public venue.

The insulation boards would be affixed to the sheathing boards overlying the building’s steel frame. The boards, in turn, would be protected beneath a weather-resistant decorative mineral render.

Design and Specification:

During the planning stage, Permarock technical staff provided the stakeholder team with visualisations, material samples and colour swatches. The associated planning application and Listed Building Consent were approved by the council’s Planning Committee in June 2020. Refurbishment works began shortly thereafter.

In subsequent stages, the Permarock team conducted pull-out tests to determine the appropriateness of the proposed systems and fixings for the substrate. Staff also provided the system installer, Rendserve, with project-specific support throughout.

The chosen EWI system comprised:

EWI systems that combine Permarock Mineral Fibre insulation and Permarock SiliconeUltra K Finish will generally achieve an A2-s1,d0 reaction to fire classification (EN 13501-1:2007 + A1:2009). This makes them suitable for use on buildings of any height, including those with floor levels of 11 or more metres above ground level.

Here, the Permarock Mineral Fibre Dual Density Insulation was supplied as boards measuring 1200 mm x 600 mm, and installed to a thickness of 80 mm. Other thicknesses were used as necessary to achieve certain details. All mineral fibre boards were affixed using both a cement-based adhesive and steel anchors.

Permarock SiliconeUltra K Finish is a highly durable but lightweight render with a 15 mm grain texture. Typically lasting over 30 years, it is water repellent and vapour permeable. It is available in around 500 shades from Permarock’s A1 Colour Range. It also features nano-quartz technology, which enables it to resist the accumulation of surface dirt, and an agent that resists mould, algae and other organic growths. As a result, regular cleaning is not normally necessary to maintain a bright, fresh appearance.

Performance and Sustainability

Permarock Mineral Fibre External Wall Insulation systems have low embodied energy and are BIM Level 2 compliant. They exhibit thermal conductivity of 0.036 W/mK, and have an Ecopoints score of 0.10 (m2). This rating is considered to be ‘excellent’.

The insulation boards are manufactured to EN 13162 and are free from CFCs and HCFCs. They have zero Ozone Depletion Potential and zero Global Warming Potential.

Result:

The 100-week scheme was completed in May 2025 and was widely greeted as a technical success. As a result of the works, the building was removed from the ‘Theatres at Risk’ register.

Moreover, the new venue was welcomed as an important new asset for North East London. The site is now managed by Soho Theatre, a charity, a social enterprise and one of the busiest theatre companies in London.

Discussing the building’s opening, Councillor Ahsan Khan, deputy leader and cabinet member for housing and regeneration said: “We are thrilled that after years of dedicated restoration, the former Granada cinema building reopened its doors as Soho Theatre Walthamstow … The revival of this iconic venue embodies our vision of Waltham Forest as a vibrant neighbourhood where there is culture on every corner. Our investment will create new job opportunities for local people, provide an important boost to the night-time economy, and open up the joy of creating and performing to a new generation. The long-term benefits will make a real difference for everyone that lives, works, or studies in Waltham Forest.”

Project
Retrofit / Public Buildings
Client
London Borough of Waltham Forest
Specifier
Bond Bryan Architects / Willmott Dixon
Substrate
Sheathing Board on Steel Frame
System
Permarock Mineral Fibre External Wall Insulation Systems
Finish
Permarock SiliconeUltra K Finish