Thermal Imaging Camera We did have access to a Thermal Imaging Camera which showed areas of heat loss from residents homes.  The Energy Advisors took a thermal image of peoples homes and this showed if there was significant heat loos through uninsulated walls.  Please see some of the thermal images here which shows areas of heat loss.
This image shows a terrace of three houses the one in the middle has no cavity wall insulation while the other two do have cavity wall insulation.
This image is taken inside a house looking at the front door.  The image shows cold air coming into the house at the base of the door.  Fitting a draught excluder to the door would reduce this.