This is general guidance based on standard permitted development rights in England. Rules differ for listed buildings, conservation areas, and properties with Article 4 directions. Always confirm with your local planning authority before starting work.
Do I Need Planning Permission for an Orangery in Hounslow?
An orangery is similar to a conservatory but features more solid walls with a glazed lantern roof. For planning purposes, an orangery is treated as a single-storey extension and follows the same permitted development rules.
Planning in Hounslow
68%
of planning applications granted
94%
decided within the statutory or agreed time
57%
of householder applications decided within 8 weeks
In the year to December 2025, Hounslow decided 1,284 planning applications. 760 of these were householder projects such as extensions, loft conversions and outbuildings, of which 72% were granted.
Planning statistics: MHCLG planning application statistics, the year to December 2025. Conservation area and Article 4 data: planning.data.gov.uk, © Historic England / Crown copyright. Open Government Licence v3.0.
Important: Additional Restrictions May Apply in Hounslow
Hounslow has 33 conservation areas. These include Bedfont Green, Bedford Park, Chiswick High Road, Chiswick House, Cranford Village, Feltham Town Centre. If your property is in a conservation area, some or all permitted development rights may be restricted. For example, you may need planning permission for changes that would normally be permitted, including alterations to the roof, cladding, or extensions visible from a public highway.
Check with Hounslow planning department before starting work to confirm whether your property is affected by any special designations.
Permitted Development Rules for an Orangery
Generally permitted under Part 1, Class A, following the same rules as single-storey extensions. An orangery is treated identically to any other single-storey rear extension for PD purposes.
Conditions
- 1Same conditions as single-storey rear extensions
- 2Maximum depth 3m (semi/terraced) or 4m (detached) under standard PD
- 3Maximum height 4m; eaves 3m if within 2m of boundary
- 4Materials should be similar in appearance to the existing dwelling
- 5Must not cover more than half the curtilage
Size and Dimension Limits
- Maximum height: 4m
- Eaves height: 3m if within 2m of a boundary
- Depth: 3m (semi/terraced) or 4m (detached) under standard PD
When Permitted Development Does Not Apply
- Same limitations as single-storey extensions
- Cumulative total of all extensions and outbuildings must not cover more than half the curtilage
- Unlike conservatories, orangeries are unlikely to qualify for the Building Regulations exemption (due to solid walls)
What About Building Regulations?
Building regulations approval is likely required
Building Regulations approval is usually required as orangeries have substantial masonry walls and are generally integrated into the house. Covers structural stability, foundations, thermal performance (Part L), ventilation, drainage, and electrical installations.
Building regulations are separate from planning permission. Even if your project is permitted development, you may still need building regulations approval. Contact Hounslow building control or use an approved inspector.
How to Apply in Hounslow
If you need planning permission for your orangery, you can apply through Hounslow's planning department or via the national Planning Portal.
If your project is permitted development and you want written confirmation, you can apply for a Lawful Development Certificate (LDC) from Hounslow. This provides proof that your project does not need planning permission, which can be helpful when selling your property.
What Happens If I Build Without Permission?
Same enforcement risk as single-storey extensions. Orangeries that exceed PD limits without permission can be subject to enforcement notices requiring alteration or removal.
Frequently Asked Questions
Do I need planning permission for an orangery in Hounslow?
Does an orangery in Hounslow need building regulations?
How do I apply for planning permission in Hounslow?
How long does planning permission take in Hounslow?
What percentage of planning applications does Hounslow approve?
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