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Significant amounts of energy through heating and cooling are lost through “leaky” buildings. This leads to more energy being pumped into maintaining a good thermal environment within the building which causes higher bills and higher carbon footprints. The amount entirely depends on the building and is dependent on how well insulated and draught proofed the building is. To improve the insulation of a building there are several steps that can be taken, although thought should be given to protecting the original heritage of the building.


It is estimated that around 25% of heat is lost through a typical roof on a traditional building and so adding loft insulation can have a significant impact and is a common step in improving the thermal performance of a building.

Generally there are two approaches for roof insulation; insulating at ceiling level which creates a cold roof space or between the rafters of the roof itself which creates a warm roof space.

There are a range of materials available including with at least 270mm recommended for it be effective:

  • Natural materials such as hemp fibre board or sheep’s wool
  • Recycled products
  • Products made from glass or modern materials

More information can be found here:


Insulating your floor can also be a great way to reduce heat loss. Usually, only ground floors need to be insulated and not upper floors. However, if you’re above any unheated spaces you could be losing a lot of heat through those spaces so any floors above unheated spaces should be considered for insulation.

Different kinds of floors require different methods and materials for insulation but can still be modified to improve their thermal performance.

  • Solid concrete floors can be insulated when it needs to be replaced or can have rigid insulation laid on top of it.
  • Suspended timber floors can be improved by retrofitting insulation materials between the supporting joists beneath the floor boards

More information can be found here:


Similar to roofs and floors, the material, location and construction of a wall will determine what kind of insulation can be undertaken.

Solid walls, either brick or stone, can be difficult to insulate due to the risk of trapping moisture for example, or it may damage the appearance of the wall. However, it may be worth considering insulation improvements if repair work needs carrying out, such as when inappropriate cement render is being removed for external walls. Render can be replaced with materials to help insulation such as:

  • Insulated lime render
  • Hemp fibre
  • Expanded clay aggregate

Alternatively coverings of solid walls can be added which help to reduce heat loss through that wall such as rigid insulation coverings or insulating plaster.

More information on solid walls can be found here:

Cavity walls are easier to insulate as insulation materials can be inserted into the cavity between the two wall sections. The insulation material for this kind of wall can be:

  • Mineral wool or fibre
  • Expanding foam
  • Polystyrene beads or foam

More information on cavity wall insulation can be found here:

A view of looking up a chimney in an old brick house of the 18th century
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