When A Conservatory Maybe An Extension

Depending on whether a conservatory is thermally separate from the main house it may be classified as an extension.

• Unheated conservatories (i.e., those without a fixed heating system connected to the house): Must be thermally separated to be exempt from full Building Regulations.

• Heated conservatories: If connected to the home’s central heating or fitted with permanent heating, the conservatory is treated as a full extension and must meet the same insulation and energy performance requirements as the rest of the house — and thermal separation may no longer be required if it meets Part L standards.

 

 

 

 

 

 

✅ Conservatories are exempt from Building Regulation if:

1. They are single-storey.

2. They are built at ground level.

3. They are under 30 square metres in floor area.

4. They are separated from the main house by external doors, windows, or walls (thermal separation).

5. They have their own independent heating system, not connected to the house’s central heating.

6. They meet glazing and electrical safety rules.

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❌ You’ll need Building Regulations approval if:

1. You remove the wall or doors between the conservatory and the main house (i.e., no thermal separation).

2. You connect the conservatory to the house’s central heating system.

3. The structure exceeds 30 m².

4. It affects drainage, access, or fire safety.

 

Bevan Surveyors can help identify the rules and regulations pertaining to conservatories.