Do I Need Planning Permission for a Conservatory?
Most conservatories fall under Permitted Development and do not need planning permission. The key distinctions are: size (same PD limits as single-storey extensions), glazing ratio (affects Building Regulations, not planning), and location (conservation areas have reduced PD).
PD rules for conservatories
PD rules for conservatories
The same PD rules apply to conservatories as to any single-storey extension: maximum 4m depth (8m for detached under Prior Approval), maximum 3m eaves height, maximum 4m overall height, and no more than 50% curtilage coverage. The fact that it is glazed does not change the planning rules.
Building Regulations and the 75% rule
If a conservatory has at least 75% of its roof glazed and at least 50% of its walls glazed, AND is separated from the house by an external-quality door, it may be exempt from Building Regulations. This means the structure does not need to meet insulation or foundation standards. However, if you plan to open the room into the house (removing the separating door), full Building Regulations apply.
Common questions
Frequently asked questions
Extension guides
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Planning permission rules for conservatories — PD limits, Building Regulations exemptions, and the 75% glazing threshold explained.
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