Existing UPVC double glazed windows have been left as they are. However, there were some failing single glazed leaded windows, with gaps! It was very draughty. These have been replaced with triple glazed windows (sandwiching the original leaded lights inside the new windows to retain the style). The draughts have been eliminated, making a huge difference to comfort.
Walls – external insulation
The majority of the wall area (9 inch solid brick) has been externally insulated and rendered by Westville Insulation. They used the Permarock system, with 60mm of Phenolic foam and a K render to form a weather-proof outer surface. Phenolic foam is more highly insulating than most other options, including mineral fibre and polystyrene, for the same thickness. The thickness of 60mm Phenolic is commonly used as this would bring a solid wall house up to the same level of insulation as a new build at 2011 building regulations.
As soon as the external insulation boards were in place, the house felt noticeably warmer and much more comfortable. Not only that, but the house started to dry out! This means that there has been some cracking of paint and plaster in the main bathroom and other areas.
The external insulation does not surround the entire house for a number of reasons. The centre of the front elevation has been left un-insulated for aesthetic reasons, as has the chimney breast. With just 60mm of insulation, the overhang at the eaves is not reduced greatly and there is no detrimental impact on the appearance of the house. If anything, the whole house looks more attractive than it did originally.