Advantages of Cellars and Basements
Whether newbuild or refurbishment, cellars and basements have a number of advantages that are driving their rise in popularity.
Basements make maximum use of available land
Planners often limit the footprint and number of above-ground storeys of a building. Including a basement can allow additional living space whilst conforming to planning requirements. Alternatively, the additional space provided by the basement can be used to free up above-ground space for amenities such as gardens.
As prime building land becomes increasingly scarce, developers and self-builders are making use of sloping land and other sites that require deep foundations. Where foundations are required to be deeper than 1m (or are piled or raft foundations) the marginal cost of including a basement is greatly reduced as it effectively provides the building with the deep foundations that it needs.
Basements increase property value
Including a basement will almost certainly increase the value of a property. Whether the increased value will exceed the additional cost involved in building or converting the basement will depend on a number of factors - e.g. the use that the basement is put to, the quality of finish, and local property prices. In areas with very high property prices, even relatively expensive basement projects such as constructing a basement underneath an existing property or garden (known as a 'dig out') can be profitable.
With stamp duty running at £20,000 on a £500,000 property or £50,000 on a £1,000,000 property a cellar conversion can often make better financial sense than moving home - especially when estate agent's fees, solicitor's fees, and other moving expenses are taken into account.
Environmental Benefits of Basements
A study carried out on behalf of the Basement Information Centre found that houses with basements are up to 10% more thermally efficient than houses of the same size constructed entirely above ground [1]. In fact, the insulating qualities of basements have been acknowledged for hundreds of years - the reason that wine is traditionally stored in wine cellars is because they provide a stable temperature throughout the year.
Where newbuild basements are constructed using reinforced concrete this can be used to provide thermal mass which can help to naturally regulate the internal temperature of the building. The benefits of thermal mass are maximised where the basement is insulated and waterproofed externally [2].
Because the inclusion of basements in developments can allow greater population densities to be achieved, the requirement to build on greenfield land is reduced.
References
- British Cement Association. Options for quality in housing. Basement 3 - Thermal performance of dwellings with basements. Crowthorne, BCA, 1993. 8pp. C/17.
- The Concrete Centre. Thermal Mass Explained.