Sanya Polescuk Architects completes the ‘wrap’ of a historic London mews house
The practice has created a live-work space which successfully marries old with new
Sanya Polescuk Architects have submitted this project into the AJ Small Projects Awards. The 2 phase retrofit of a Victorian house in Belsize Park, London has transformed the building into a live-work environment, winning a commendation in NLA’s Don’t Move, Improve! Awards.
Formerly a coach and stables mews house, the project is situated within a conservation area, which led to some interesting challenges. By retaining the original features of the former Victorian mews, the architects have paid respect to the historic value of the structure whilst meeting the needs of modern thermal efficiency standards.
After removing the domestic additions of recent years, a single open horseshoe shaped workspace was created on the ground floor with independent access from the mews.
The existing structure of the house is load bearing solid brick walls, typical of buildings of this age. A single timber beam spans ten metres across and is propped up only by one cast-iron column. This allowed them to create an open span area containing the circulation and studio space.
To increase thermal performance and reduce the building’s carbon footprint, the structure has been ‘wrapped’ with insulation.
The ground floor studio area was insulated with breathable wood fibre insulation to the walls and floor, allowing the existing fabric and insulation to breathe together.
The first floor maisonette living space has been internally sealed with PIR insulation on the walls and roof. The fabric breathes through a ventilated cavity between the existing building fabric and the insulation.
Windows can often be a problem when retrofitting in conservation areas, with planners often requiring original timber sash windows to be kept despite their inefficiencies. For this project Sanya Polescuk Architects worked with the existing windows, adding secondary glazing at ground floor level, and at first floor the original sash windows were overhauled, draft proofed and new Histoglass double glazing installed.
The maisonette living areas of the retrofit follow Code for Sustainable Homes guidelines, achieving Level 4.
The success of this retrofit project lies in its sympathetic marrying of old and new. The character and style of the original coach and stable mews has been kept through the careful retention of historical details such as the wall tiles and cobblestone floors. Where elements have had to be changed to fulfil requirements of a modern live-work environment, a nod to the past has been kept, for instance, the outline of the original stairs to the hayloft has been painted white on the wall, leaving a shadow of the building’s past existence.
Contract period phase 1 March – July 2011
Contract period phase 2 January – August 2012
Gross internal floor area: 185m²
Form of contract Traditional JCT Minor Works
Total cost £240,000
Annual predicted CO2 emissions 25.8kgCO2/m²
Air tightness levels 9.56m³/hr/m²
Predicted energy demands for studio and flat gas: 10,756kWh/year, electricity: 2,340kWh/year
Environmental targets Code for Sustainable Homes Level 4
Wall U-values 0.20W/m²K
Floor U-values 0.20W/m²K
Roof U-values pitched slate: 0.13W/m²K, lead dormer: 0.15W/m²K
Glazing U-values original timber sashes with new Histoglass: 1.9W/m²K, new timber framed casements: 1.1W/m²K, new aluminium roof light: 1.0W/m²K
Renewables solar thermal hot water
Architect Sanya Polescuk Architects
Structural engineer Michael Chester & Partners
Main contractor A&I Contstruction
Testing Air Pressure Testing
Key suppliers Steico Natural Building Products, Celotex, Enviko Renewable Energy Solutions, Vent-Axia, Histoglass, Natural Windows, VELUX, Isaacs Glass Company