Case Studies - The Effectiveness of External Wall Insulation

Project Description
  • 6th April 2018

The Aim:

A survey of ‘before and after’ images of the wall insulation cladding project was conduct to see how much heat saving was made.

The Case:

Magna Housing asked ThermoSurvey to conduct a ‘before and after’ survey on six of its houses.  Thermal imagery was used to survey the ex Army properties on the South Coast.  The aim was to identify heat loss and where it was coming from.  The company had recently put new roofs on the buildings with increased insulation.

Prior to any external wall insulation, the walls of the buildings showed a mosaic of different temperatures. The average temperature  of the walls during that day was 3°C with a variation of 1°C. The weather conditions were overcast and very cold, perfect conditions for this study.

House prior to insulation

ThermoSurvey was able to survey examples from the start of the external wall insulation process as discussed above, through to the end product. The middle stage of the process consisted of bolting on external cladding and finally spraying on an insulating product as the finishing render.


The final set of pictures show that the external walls were averaging  0.5°C with a 0.2°C variation. This shows a very significant heat saving and a greater standardisation of wall covering than previously. If one considers a 2°C difference between the two standards of wall and multiplies this difference by the surface area of the building envelope, a real saving will be made by the large reduction of heat loss especially over the lifetime of the building.

New insulation



Thanks to ThermoSurvey, Magna Housing were shown exactly how effective their energy saving program was, through temperature change and subsequent energy efficiency.

The Feedback:

“An excellent study – couldn’t be better, we can really show our tenants what we are doing”