There are a number of wood-boring insects that attack timber in properties in the UK. The three most common wood-boring insects likely to cause problems are:

Common Furniture Beetle:
By far the most common insect estimated to infest about 75% of properties in the UK - not just found in very old properties but also quite common in houses built in the 1940s', 50s' and 60s'. In some instances the infestation will die out of its' own accord but this largely depends on the type and 'quality' of the timber used and the conditions surrounding it.

Treatment is relatively straightforward and usually involves spraying exposed timbers with and insecticidal fluid.
The process is quick - a typical house can easily be treated in a day and modern fluids allow for 1-hour re-entry.

Death Watch Beetle:
This insect confines itself to infesting large sectioned hardwoods, often associated with an attack of Wet Rot and for this reason is usually caused initially by a building defect such as roof leaks, faulty rain water systems of structural defects.

As it only attacks hardwoods it is normally found in older properties and is unlikely to be a problem in buildings less than 150years old, but can cause considerable damage once established.

Wood-boring Weevil:
Wood Weevil is an insect that prefers extreme damp conditions and decay. Chemical treatment is therefore not always necessary as dry timbers will not be affected by Weevil.

Generally

In all these cases, some timber repairs may be required, however this is more likely with Death Watch beetle and Weevil infestations.

Modern treatment techniques

Water based micro-emulsion insecticides
Treated rooms can be re-occupied after just one hour
Water based = non flammable
Generally applied by spray but can also include brush application, injection and in gel or paste formulations including Boron products
Low odour, low hazard and HSE approved