Islington Conservation Area Refurbishment

Our clients wanted to update their run down, but beautiful Victorian house into a high quality, modern, comfortable family home. After employing the architects Cousins & Cousins to create the overall concept and plans for the extension and refurbishment, they contacted greentomatoenergy to see if they could improve the energy performance and comfort.

The semi-detached property of just over 210m2 (after the extension) is located in a desirable conservation area on a tight site with strong aesthetic restrictions from the planners.

greentomatoenergy started by providing a design review which established there was potential to transform the energy performance and comfort of the property using high performance glazing, internal wall insulation and creating an airtight building that could be ventilated with MVHR as well as use smart heating control and solar thermal. The clients agreed to this challenge and greentomatoenergy set about collaborating with the architect to make it happen providing consulting services including technical design support, PHPP modelling, onsite support, air-tightness training and testing.

Once the contractor, Lovedays, was selected to build the project, they also selected the greentomatoenergy delivery team to support them by supplying and designing, supplying and installing the heating and plumbing systems.

The refurbishment aims to achieve a heating demand of 50kWh/m2, ambitious for a refurbishment of this type and the peak heat demand is close to 1/3 of a normal Victorian house of this type.

The refurbishment, basement and extension includes the application of IWI on the existing walls, the construction of new super-insulated cavity walls, the application of roof and floor insulation. Only double glazed sash windows could be installed due to planning restrictions. A carefully selected air-tightness strategy was applied and a Mechanical Ventilation with Heat Recovery system with bespoke hidden valves was installed. The heating system uses a high efficiency gas system boiler and a large storage tank for solar heating. Internet linked smart heating controls are also used with the zoned underfloor and radiator heating system.

The project is under construction.

  • Front view of the North London eco home pre-retrofit
  • Front door at the North London eco home pre-retrofit
  • Solar thermal being installed to the south-facing roof of the future eco home
  • Breaking a thermal bridge in the steel frame of the eco home with Insula material
  • Demonstrating airtightness strategy in sealing electrical services entry and exit points that pass through the airtight membrane