Properties Suitable for External Wall Insulation

26-07-2017 Back

Can I get External Wall Insulation (EWI) on a:

  Old house

    Yes, if the property has solid walls. You may need to apply for planning permission depending on where you live. If your home was built before the 1920s EWI is likely to be the most suitable wall insulation system, whereas newer homes tend to have cavities that are suited to cavity wall insulation.

  New build

    In theory, but you shouldn’t need it. Most new builds are already built with insulation boarding between the internal and external walls.

  Terraced house

    Yes, if the property has solid walls. EWI will be applied to the front and back of the house (and gable end if you live in an end terrace).

  Listed building

    It depends on the specific property. You will need to apply for planning permission and it may be refused, depending on where you live.

  Brick house

    Yes, if the property has solid walls. You can find out if your house has solid walls by looking at the brick pattern.  You could also choose to have a brick slip finish on your EWI system so that it looks the same as a brick property.

  Victorian house

    Yes, if the property has solid walls (which it probably will). EWI is suitable for Victorian and Edwardian houses as they are unlikely to have a cavity. You may need planning permission if they are listed or situated in a conservation area.

  Park Home

    Yes, most Park Homes are suitable for EWI. However, some older Park Homes may require strengthening work before the insulation boarding can be applied.

  Timber framed house

    Yes, there are EWI systems available for timber framed houses, but it must be installed to ensure that moisture cannot get through to the frames and cause rot. This can involve installing a vapour barrier to protect the frames.

  System built house

    Yes, almost all system built properties have solid walls and are ideally suited to EWI.

  Below DPC (damp-proof course)

    Yes, though this is unusual.

  Around windows & doors

    Yes, the system is sealed to all openings to provide a weather-tight finish.

  Over pebble dash

    Yes, however EWI needs to be installed on a flat surface, so sometimes the pebble dash may need to be removed or smoothed over with render to begin work. Your installer will be able to assess this and offer solutions.

  Over render

    Possibly. Guidance should be sought from the system designer. If the render is in poor condition then it should be removed. Render is put on the outside of the insulation anyway, so the original aesthetic can be maintained.


More Information from YES Energy Solutions:

•    External Wall Insulation – A Simple Guide
•    EWI FAQs
•    Funding & Grants for EWI
•    External Wall Insulation vs Internal Wall Insulation