Alterations to existing buildings
In its broadest sense, alteration can be defined as: ‘Work intended to change the function or appearance of a place.’ Ref Conservation Principles, Policies and Guidance, For the sustainable management of the historic environment, Published by Historic England in 2008.
Existing buildings often undergo alterations during their life to change, modify or improve their performance or the nature of their use.
Common examples of alterations include:
- Total or partial change of use.
- Extension.
- Partial demolition.
- Linking or separating spaces.
- Making or closing openings.
- Retrofitting a new a component or feature.
- Refurbishing an existing a component or feature.
- Renovating an existing component or feature.
- Repairing an existing component or feature.
- Maintenance.
- Decoration.
Some alterations may require planning permission. Other alterations may be considered 'permitted developments' for which planning permission is not required.
Examples of permitted developments include; certain enlargements or alterations to houses, construction of some sheds and fuel storage containers, certain porches, doors and windows, and so on. The best way to determine whether a development is permitted or not is to ask the local planning authority.
For more information see: Permitted development.
Responsibility for determining panning permissions generally lies with local planning authorities (usually the planning department of the district or borough council).
For more information see: Planning permission.
The building regulations may also apply to alterations. The building regulations set out:
- What qualifies as ‘building work’ and so falls under the control of the regulations.
- What types of buildings are exempt (such as temporary buildings).
- The notification procedures that must be followed when starting, carrying out, and completing building work.
- Requirements for specific aspects of building design and construction, such as; structure, drainage, fire safety, conservation of fuel and power, access for people with disabilities and so on.
Building regulations approvals can be sought either from the building control department of the local authority or from an approved inspector.
For more information see: Do the building regulations apply to existing buildings?
On larger projects, the The Construction (Design and Management) Regulations (CDM regulations) may also apply. The CDM regulations are intended to ensure that health and safety issues are properly considered during a project’s development so that the risk of harm to those who have to build, use and maintain structures is reduced.
For more information see: CDM regulations.
NB The 2018 International Residential Code (IRC), published by the International Code Council (ICC) defines alteration as: ‘Any construction, retrofit or renovation to an existing structure other than repair or addition that requires a permit. Also, a change in a building, electrical, gas, mechanical or plumbing system that involves an extension, addition or change to the arrangement, type or purpose of the original installation that requires a permit.’
[edit] Related articles on Designing Buildings
- Building regulations.
- CDM.
- Change of use class.
- Do the building regulations apply to existing buildings?
- Flexbury Church.
- Henry Boot Construction Ltd v Alstom Combined Cycles.
- International Existing Building Code (IEBC).
- Material change of use.
- Planning digital signage in new buildings.
- Planning permission.
- Permitted development.
- Refurbishment.
- Renovation.
- Retrofit.
Featured articles and news
Deputy editor of AT, Tim Fraser, discusses the newly formed society with its current chair, Chris Halligan MCIAT.
Barratt Lo-E passivhaus standard homes planned enmasse
With an initial 728 Lo-E homes across two sites and many more planned for the future.
Government urged to uphold Warm Homes commitment
ECA and industry bodies write to Government concerning its 13.2 billion Warm Homes manifesto commitment.
Places of Worship in Britain and Ireland, 1929-1990. Book review.
The emancipation of women in art.
CIOB Construction Manager of the Year 2025
Just one of the winners at the CIOB Awards 2025.
Call for independent National Grenfell oversight mechanism
MHCLG share findings of Building Safety Inquiry in letter to Secretary of State and Minister for Building Safety.
The Architectural Technology Awards
AT Awards now open for this the sixth decade of CIAT.
50th Golden anniversary ECA Edmundson awards
Deadline for submissions Friday 30 May 2025.
The benefits of precast, off-site foundation systems
Top ten benefits of this notable innovation.
Encouraging individuals to take action saving water at home, work, and in their communities.
Takes a community to support mental health and wellbeing
The why of becoming a Mental Health Instructor explained.
Mental health awareness week 13-18 May
The theme is communities, they can provide a sense of belonging, safety, support in hard times, and a sense purpose.
Mental health support on the rise but workers still struggling
CIOB Understanding Mental Health in the Built Environment 2025 shows.
Design and construction material libraries
Material, sample, product or detail libraries a key component of any architectural design practice.
Construction Products Reform Green Paper and Consultation
Still time to respond as consultation closes on 21 May 2025.
Resilient façade systems for smog reduction in Shanghai
A technical approach using computer simulation and analysis of solar radiation, wind patterns, and ventilation.