Stoke Aldermore, Coventry

Wimpey No Fines Properties

Project Background

Insuletics ascertained in October 2012 that Drax Power had surplus CESP funding. Insuletics approached Savills and Whitefriars Housing Group and established that 134 No. Wimpey No-Fines properties on the Stoke Aldermoor estate were suitable to be refurbished using the Insuletics BBA approved external wall insulation systems. The Wimpey No-Fines type property were built between 1940’s – 1970’s and consists of cast insitu 10” thick concrete walls that are rendered externally and wet plastered internally. The concrete used was a mix of cement and coarse aggregate only giving the concrete a honeycomb type structure. The U value of the existing walls is poor by today’s standards at 1.65 w/m2K and they are therefore ideally suited for this type of thermal upgrade.


Working closely in conjunction with Savills, Whitefriars Housing Group and Astley Facades (Midlands Ltd) the project was very rapidly designed, detailed and within a two week period work had commenced on site.

In order to maximise the CESP funding available it was important that as many properties as possible were insulated prior to the Christmas 2012 shut down.

A total of 134 No. properties had been insulated and 30 No. properties finished and weatherproofed prior to Christmas, a three week period from a standing start.

Project Challenges

Due to the very tight time scale for this project it was important that all of the design and detailing was completed very quickly. Insuletics used their own In – House fixing test equipment and engineers to undertake the required assessment of the fixings eliminating the need to wait for a fixing supplier to attend site.

The client requested that the render finishes matched some finishes that had previously been applied. Insuletics quickly provided sample boards of the selected finishes to allow the final selection by the client.

The existing GRP canopies were relatively new and as such the client requested that these be re-used. The canopies were carefully removed and stored on site. Timber pattresses were then fixed within the new external wall insulation system to provide a strong fixing point for the re-attachment of the canopies

In order to assist with the funding process Insuletics undertook weekly quality control site inspections and sign off sheets. Assistance was also provided with the funding evaluation and carbon banking administration to allow the timely release of the funds.

The System & Results

The systems used were the Insuletics Insul-Dash E™ and Insul-Cryl E™. These systems incorporate a 90mm enhanced grey expanded polystyrene insulation material that has a thermal conductivity of 0.032 w/m2K. This enabled the target U value of 0.3 w/m2K to be achieved.

By using enhanced grey expanded polystyrene in lieu of the more commonly used white polystyrene it was possible to reduce overall thickness of the external wall insulation system.

The Insuletics mechanically fixed EWI system enabled the 134 properties to be fully insulated prior the Christmas demobilisation, just 3 weeks after commencement on site. This would not have been feasible with an adhesive fixed system due to the prevailing weather conditions and low temperatures.

The houses were completed within 3 months including the Christmas shut down.

The majority of the walls were clad with the Insul-Dash E system with a cream or grey dash receiver render combined with three different dash aggregates Ashton Cream 3 – 8 mm, Caledonian Harvest 3 – 8 mm or Westbere Spar 3-8mm In the recessed panel areas only the Insul-Cryl E system was used with a Insul-Acryl 1.5mm grade acrylic finish in dark cream colour (Corn) or a Grey colour.