Internal Solid Wall Insulation
Circa 35% of heat is lost through external walls.
Our preference is to insulate walls externally. The reasons are because your solid walls are an excellent thermal store of energy when insulated externally, air tightness can be controlled, thermal bridging is virtually eliminated, there will be less disruption to your family, and the internal area of rooms is not reduced. However, external wall insulation cannot always be used due to Local Authority restrictions. In such cases, you would need to insulate internally.
The methods to insulate external walls on the internal face fall into two broad categories. These are non breathable products (e.g. laminated plasterboard), or breathable products (mineral or sheep's wool, timber, hemp, calcium silicate). The method of fixing varies, but comprises either direct application to the wall, or the use of timber or proprietary studs.
All of these systems will result in a minor reduction in the room area commensurate with the thickness of the insulation, and disruption in the use of the room.
Prior to insulating walls surveys should be undertaken. These ascertain whether the wall is breathable or not breathable, and the extent of any damp within the wall. The survey will therefore dictate which method of insulation can be used. The cause of any damp and drying out of the wall need to take place prior to the application of insulation.
Typical costs are in the region of £5,000-£8,500, giving annual savings of £445. The payback period is up to 19 years, with annual carbon savings of 1.8 tonnes*.
If you would like to view the blog on the green conversion and renovation of a Victorian London apartment, click here.
*Energy Saving Trust 2011