- Project plans
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Last edited 30 May 2019
A building may need to be altered at some point after it has been constructed during its in-use period. This will necessitate alteration work.
Alteration work may be required for a wide range of reasons, including:
- Factors unforeseeable at the design stage, e.g new efficiency standards become possible.
- Total or partial change of use e.g an office block converted into housing.
- Change of ownership necessitating enlargement, extension or other changes.
- Failure of building components.
- Changing technological possibilities.
- Wear and tear.
Common examples of alterations include:
- Partial demolition.
- Linking or separating spaces.
- Making or closing openings.
- Retrofitting a new component or feature.
- Refurbishing an existing component or feature.
- Renovating an existing component or feature.
- Repairing an existing component or feature.
Alteration work may be instigated by:
- The building owner.
- The building tenant (with the owner’s permission).
- The local authority (e.g if it needs to take urgent action or has instigated a compulsory purchase order).
- Central government (e.g. changes in regulations).
Alteration work can be complex and may involve higher design and construction fees than new build work. Appointing a designer or contractor to carry out the works may be on the basis of a firm that has successfully undertaken work in the past and is trusted by the client/building owner; or by inviting firms to tender for the work in an invitation to tender (ITT).
Some alteration works may require planning permission while some may be considered ‘permitted development’ for which planning permission will not be required. The best way to determine whether a development is ‘permitted’ or not is to refer to the local planning authority.
Examples of permitted development include:
- Certain enlargements or alterations to houses.
- Construction of some sheds and fuel storage containers.
- Certain porches, doors and windows.
For more information see: Permitted development.
Alteration work may also require building regulations approval.
For more information see: Do the building regulations apply to works to existing buildings?
The term ‘alteration work’ as used in this article should not be confused with alterations to the scope of works of a construction contract, which are more commonly known as ‘variations’. Variations are changes involving addition, substitution, or omission to the original scope of the construction contract, and can affect the design, quantities, quality, working conditions or sequencing of the works.
For more information see: Variations.
 Related articles on Designing Buildings Wiki
- Building regulations.
- Change of use class.
- Do the building regulations apply to existing buildings?
- Henry Boot Construction Ltd v Alstom Combined Cycles.
- International Existing Building Code (IEBC).
- Material change of use.
- Planning permission.
- Permitted development.
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