As warm air rises the roof is a good place to start with insulation. It is also one of the easiest places to add insulation in most buildings.
For most roofs placing insulation above the ceiling of the top floor can be cheaply and easily achieved.
Read more about insulating roofs at ceiling level:
For buildings with rooms in the roof, insulation can be added either above between or beneath the sloping rafters. However, the building might pose certain constraints which may mean not all these options are possible.
Read more about insulating roofs at rafter level:
Many older buildings have areas of flat roof, typically over extensions or porches. Insulating these areas can in many cases be quite difficult so care is needed to make sure the work is effective and does not cause technical problems.
Read more about insulating flat roofs:
Older buildings often have dormer windows which come in a variety of shapes, sizes and materials. If the main roof is being insulated then it would be advisable to consider insulating any dormer windows as well.
If a roof has thatch as a roofing material you may not need to add any insulation as the thatch if well maintained will already have good insulation properties.
Read more about insulating dormer windows and insulating thatched roofs: