The Roof
The roof doesn’t just keep rain out, but keeps heat in as well. Your roof will typically lose 25% of your home’s heat unless it’s sealed and insulated.
Some aspects of roof construction have changed little in centuries. The most common form in the UK remains a pitched roof built from a timber truss topped with slates or tiles for weatherproofing. There is often an attic space within the roof although increasingly this is being converted into an extra room.
There are endless variations of roof structures, but some of the common elements are shown below. The rafters and ceiling joints form the main frame. The purlins, struts and binders tie the frames together and provide extra stiffness. The slates or tiles are fixed to closely-spaced battens which run across the rafters. Since the 1950s a layer of underfelt has typically been added underneath the battens to provide an additional layer of weatherproofing, but this might not be present in older houses.
Elements of a typical timber roof frame. This basic structure has been used in British housing for centuries with only minor variations. If your attic space is accessible, adding loft insulation is one of the easiest and most effective ways to keep your house warm.
The good news is that adding loft insulation is one of the easiest and most cost-effective improvements you can make. If you have an empty attic then thick layers of wool-type insulation can be installed between and over the joists for a quick and effective upgrade. Insulating the roof becomes more complicated if you've extended into the attic, but there are still ways to do it. See our section on loft Insulation for more details.
Adding loft insulation between and across the ceiling joists within an attic. See our page on loft insulation for instructions
Chimneys are another source of energy loss. Any chimneys which are no longer used can be sealed to prevent uncontrolled loss of warm air. See our sections on ventilation and draughtproofing.