London Planning Permissions: What You Need to Know 
Getting your head around which home renovations require planning permission in London can be a daunting task. That’s why we’ve put together a starter guide so you can get on with designing your dream home headache-free.
What Are Planning Permissions?
Planning permissions are a right to build or renovate your house. They are granted by your local Borough Council and exist to safeguard privacy rights and the aesthetic look of buildings and neighbourhoods.
If you need planning permission, you must apply before starting work or you could be served an enforcement notice and made to undo everything.
Home Renovations That Need Planning Permissions
You need planning permission to build something new, make a major change to a building or change the use, especially if it impacts on your neighbours or the environment.
Usually, this means any changes to the front of your house or additions like extensions, which require permission if they:
- Are two storey, extend over 3 m from the rear wall or to within 7 m of the rear boundary.
- Are single storey and extend over 8 m from the rear wall of a detached house (6 m for other homes) or over 4 m high.
- Are on the side of the house (aka a ‘side return’), over 4 m high or wider than half the original house.
- Are on the front or side facing the road.
- Are higher than the original roof or alter the shape, including loft conversions.
- Occupy more than half the land around your house.
- Have balconies, verandas or raised platforms.
Other renovations that require permission:
- Splitting a house into flats.
- Building garages or outbuildings over 4 m high or which occupy over half your land.
- Building garden walls, fences or platforms over 2 m; 1 m by a road.
- Any internal or external work on a listed building or in a conservation area.
Even if you don’t need planning permission, you will need a Party Wall Agreement to work on walls shared with neighbours. A surveyor can draw up plans and mediate to help you reach an agreement.
You also need Build Over Permission from your local water board if you have sewers under your property.
Home Renovations That Don’t Need Planning Permission
Permitted Development Rights (PDRs) function as an automatic grant of permission for certain constructions, renovations and changes of use, so you don’t need to apply.
There are some limitations and conditions (mainly size and location). However, as long as you use compatible materials and haven’t already made substantial modifications to your home, you can do most internal and some external home renovations under PDRs.
- Extensions that don’t exceed the specifications above.
- Loft conversions under 40 m3, without altering the roof. In some cases you can alter the roof to do a loft conversion under permitted development rights.
- Conservatories and sheds, depending on size and use.
- Replace the roof, with certain limitations.
- Convert an attached garage to a living space, without extending it.
- Convert a free-standing garage (having applied for a change of use under Building Regulations).
- Redesign the interior, move internal walls and create open plan living spaces. You will need an architect and engineer, though, to remove supporting walls.
- Install double glazing, changing back windows and doors and add new openings, as long as upper floor side windows have obscured glass. You can often do front windows and doors too, but note that bay and dormer windows count as extensions.
- Add rooflights that extend less than 15 cm from the roof.
- Install solar panels, as long as these aren’t higher than the roof or protrude over 200 mm from the wall or roof.
- Install insulation.
- Add cladding to the façade.
- Convert the basement, as long as no engineering work is required.
Note that you will still need Building Regulations approval to certify a safe and energy-efficient renovation.
Who Handles The Planning Permissions?
You can research and apply for planning permission yourself. Decisions take up to 8 weeks, longer for very large or complex requests, so make sure you apply in plenty of time. If it takes longer or is denied, you can appeal.
Alternatively, you can hire an architect, designer or general contractor who can talk you through everything and handle applications. If taking this route, look for someone with a good track record of getting their plans approved.