House type

Housing construction methods have altered much over time. This has been driven by wider factors like technological advancements in materials, skill levels, transport costs, manufacturing practices, energy costs, equipment, social factors, fashion etc.

1919 is seen as a key date in terms of the building industry when most properties changed from being solid walls made of local stone and brick to cavity ones. However, early cavities should be treated as solid walls as they didn’t become consistent until after 1945.

Post 1945 there was a boom in ‘system built’ homes. These were largely concrete or metal framed buildings and these are quite different from conventional cavity walled properties.

The 1960’s and 70’s saw a rise on conventional cavity walls, but also other types of construction like cross wall.

After the 1990’s the trend has been towards timber framed building with brick cladding.

Building regulations have also changed over time and so there are varying levels of performance associated with these buildings.

Properties don’t stand still though. An 1850’s house may well have a flat roof extension from the 1970’s and a conservatory from the 2000’s. These changes may have been made well, or not. How all these links and affect each other can be key to the current performance of the house.

Older houses will have changed in other ways too. They will have moved their washing facilities from the out-house into an internal bathroom. Central heating has probably replaced open fires in each room. Double glazing will have superseded single. Lofts may be insulated. Lime render may have been sacrificed in favour of cement. Etc.

As well as construction materials, techniques and history, house types vary with its form. Terraces are fundamentally different to detached properties. Individual houses are fundamentally different from blocks of flats. Form creates a range of restrictions for the house owner. These risks need to be managed accordingly. For example, in a terrace or semi-detached what you do to your property affects the neighbouring one. Retrofitting changes how moisture and heat works in the building’s structure. This in turn then has an impact on any adjoining buildings, so care is needed to make sure that your improvement works don’t adversely affect your neighbours.

Recognising, understanding and taking house types into account is a vital element of risk management in retrofit.