Housing works

Insulation in council homes

Insulation and draught-proofing is used to reduce heat loss, which help to reduce your energy bills. Where it is possible, we insulate walls, lofts, under floors and provide windows and doors that also help to reduce heat loss. Find out about the different types of wall insulation.

Internal wall insulation (IWI)

Internal wall insulation is done by the council in our solid stone houses, so those usually built before the 1900s. The work is done when the buildings are empty in between lettings.

If your home has IWI the inner face of all the external walls, and any rooms in the roof, have all been stripped back, framed out and insulated with solid insulated boarding and finished in plasterboard.

It is likely that as part of the work the building would have also had:

Benefits of IWI:

  • Saves money on energy bills by keeping your home warmer
  • Makes your home feel more comfortable

Keep in mind, IWI:

  • makes rooms a bit smaller because of the thickness of the new insulated internal wall
  • requires care when fixing things to the walls
  • can cause internal dampness if not installed properly, due to cold spots where insulation layer is thinner than the surrounding areas
  • can limit airflow and reduce ventilation, so MVHR will be fitted

Find out more about how internal walls are insulated.

External wall insulation (EWI)

External wall insulation (EWI) adds a layer of insulation to the outside wall, then covers it with a hard protective rendered coat.

EWI is used for homes with solid walls, (not traditional stone walls) that need better insulation, where other methods, like cavity wall insulation, won't work.

Benefits of EWI:

  • stops heat from escaping through your walls, so the energy you use in the home should be less
  • makes your walls more resistant to weather and noise
  • it can make older buildings look new again

Keep in mind, EWI: 

  • may reduce natural draughts and make you home more airtight, checks will be needed so make sure your mechanical ventilation is good enough
  • can let in water through any hole or crack to the outside layer, especially if the new render surface has been damaged by impacts

Fixing items to EWI wall surface

If you have EWI, this means you can't fix any of the following to the wall of your home:

  • Christmas lights and decorations
  • Clothes lines
  • Trellises and plant holders
  • Outside security lights
  • Outside taps
  • Handrails

However, if you get our written consent we may agree to:

  • Installation of a satellite dish as long as you, or your satellite installer, use the approved fixing method that will be set out in your consent letter
  • Outside taps, if the pipework is brought out below the EWI and is then supported on a freestanding pillar
  • Handrails, if installed using the correct fixing method

Please note that any existing satellite dishes and outside taps will be removed and refitted in the approved method by the contractor installing new EWI.

All tenants should note that if they have made any fixings without consent they could be liable for the cost of repairs to fix any damage.

Cavity wall insulation (CWI)

Houses built after the 1920s often have a gap between the inner and outer walls of the building called the cavity. Cavity Wall Insulation (CWI) is useful for these homes if they don't already have insulation in the gap.

Materials like mineral wool, foam, or expanded polystyrene beads are used for insulation. Right now, the council uses beads and most older style cavity fill insulation has now been replaced.

How it works: small holes are drilled in the outer wall, and insulation is pumped in. After that, the holes are filled up, so you can hardly see them. 

Benefits of CWI:

  • Saves money on energy bills by keeping your home warmer
  • Makes your home feel more comfortable

Keep in mind, CWI:

  • can limit airflow and reduce ventilation because homes built with a cavity were not designed to have the gap filled
  • can lead to internal dampness for homes in areas where the external walls are regularly exposed to heavy rain and wind
  • requires any cracks to outside walls need to be fixed to prevent rainwater getting in and making older style cavity insulation wet, which can cause damp
  • can create cold spots, known as 'cold bridging' if not enough insulation is installed, or if it is uneven: this can attract moisture in the air, causing internal problems like black mould

All homes with CWI should be registered and have a 25-year guarantee certificate from the Cavity Insulation Guarantee Agency (CIGA). We will check this for you.