In order to achieve long-term sustainability and best value for the investment made, buildings and infrastructure need to be able to respond quickly and cost-effectively to changing demands.

 

A building that can be adapted to different uses over a long period of time will provide better value than one that can only be used for limited purposes that may need to be demolished and replaced relatively quickly. Good examples of such adaptability are the conversion of 18^th and 19^th century factories and warehouses into flats and commercial premises following the decline of the industries for which they were originally built. This is particularly true in Leicester, where several disused hosiery and knitwear factories have been converted into desirable flats and offices. This contrasts with the waste in recent decades when prematurely obsolete offices and flats have had to be demolished.

 

Demolition of older buildings can sever historic links or result in the loss of architectural merit, as well as much-appreciated local character. It is often more costly in energy and materials resources to demolish and rebuild. It can lead to increased waste, which is neither recovered nor recycled. The construction process itself is intrusive and often problematic.

 

Buildings lose their present usefulness for various reasons, including inadequate budgets for maintenance, poor initial standards of construction, obsolescence and being the wrong type in the wrong place. Demolition is often the only option for buildings that cannot easily or economically be adapted - for example, a tower block made of load-bearing concrete panels or with inaccessible services such as under-floor heating. On the other hand, many older buildings remain useful for several reasons including their relatively generous space layouts and accessible voids in floors and ceilings mean that service installations can be upgraded relatively easily.