Planning permission in Hertsmere
Hertsmere Borough Council decides planning applications in Hertsmere. This page shows the protected areas that affect what homeowners can build without planning permission, and the planning data Hertsmere publishes.
Conservation areas
Hertsmere has 16 conservation areas. In a conservation area, permitted development rights are reduced: side extensions, two-storey extensions, loft dormers and cladding all need planning permission, and many councils add Article 4 directions on top.
- Aldenham
- Bushey Heath High Road
- Bushey Heath the Lake
- Bushey High Street
- Bushey Melbourne Road
- Elstree Village
- Letchmore Heath
- Patchetts Green and Delrow
- Potters Bar Darkes Lane (West)
- Potters Bar the Royds
- Radlett North
- Radlett South
- Ridge
- Round Bush
- Shenley Village
- South Mimms
Read more: extensions, loft dormers, garden rooms and solar panels in a conservation area.
Article 4 directions
Hertsmere hasn't published any Article 4 boundaries on planning.data.gov.uk. Most councils have at least one Article 4 direction, often in conservation areas, so check the council's website or ask its planning team before relying on permitted development.
What is an Article 4 direction?
National parks, National Landscapes and green belt
- There is green belt in or bordering Hertsmere. Householder permitted development rights apply as normal in the green belt, but if you need planning permission, green belt policy limits how much a home can be enlarged.
Listed buildings and protected trees
Listed buildings everywhere in England are recorded by Historic England, and the checker looks for them at every address. Hertsmere doesn't publish listed building outlines, so where a listed building is recorded near an address, we ask the homeowner to check whether it's theirs.
Hertsmere doesn't publish its tree preservation orders as data. If there are mature trees near your project, ask the council whether any are protected before you start.
What Hertsmere publishes
| Data | Status | Records |
|---|---|---|
| Conservation area boundaries | Published | 16 |
| Article 4 direction boundaries | Not published | 0 |
| Listed building outlines | Not published | 0 |
| Tree preservation order areas | Not published | 0 |
| Protected trees | Not published | 0 |
Planning work on a home in Hertsmere? Put a pin on your house and we'll check it against all of this.
Start a checkData from planning.data.gov.uk, published by Hertsmere Borough Council and national bodies under the Open Government Licence, last updated here on 30 October 2026. Hertsmere Borough Council website.