Building Regulations If you live in England and Wales, conservatories are usually exempt from building regulations. As a general rule to qualify for this exemption, your conservatory should meet the following criteria laid out under the 1991 Building Regulations:

1. The extension has a completely transparent or translucent roof.
2. The extension's walls are substantially glazed (no more than 25% of its wall area should be brickwork).
3. The extension has a floor area not exceeding 30m2.
4. The extension is sited at ground level.
5. The conservatory is separated from the house by external quality door(s).
6. Glazing and any fixed electrical installations comply with the applicable building regulations requirements.

Disclaimer: This is an introductory guide and is not a definitive source of legal information. You should contact your local planning and building authority before undertaking any work.
You can also visit Direct Gov for further information