Do you

need planning permission?


So you’ve found your dream home! Well almost, but not quite.  An extension, loft conversion or basement would make it so.  But what about planning permission?

As a rule of thumb planning permission is generally required when constructing new buildings, extensions or undertaking major alterations to a building. 

If you are going to sin, sin against God, not the bureaucracy. God will forgive you but the bureaucracy won’t.”

— Hyman G. Rickover


Most smaller refurbishments that do not include an extension to the existing building or alteration to the front facade, will likely not require formal planning consent.  However, there are any number of exceptions to that rule.  

If you are intending to extend a property, then if at all possible we advise securing planning permission first.  Otherwise you could potentially end up disappointed by a home that is too small for your needs. You don’t have to own the property in order to apply for planning permission.

Securing planning is always a challenge, but the size of the challenge is largely dependent on extent of the proposed works.  Generally speaking, the more radical the proposed design, the more difficult it is to go through the planning application process and secure the required consents.


Notwithstanding the above, there are exclusions and allowances for smaller developments under the Permitted Development Act.  This allows householders to increases the size of their original property by more than 15% or 70 cubic metres, whichever is greater.   Small extensions that meet certain parameters can be carried out under Permitted Development which removes the requirement for a formal planning application. In  reality however, most extensions to properties in London will require formal consent.

There are restrictions to Permitted Development; for example, a development must not:

  • Be nearer a road, footpath or other type of public access than the nearest part of the original building, unless there is at least 20 metres between the road and your extension.
  • Cover more than half the area of land around the original building.
  • Be taller than the highest part of the original building’s roof.
  • Be higher than 4 metres within 2 metres of your property boundary.
  • Be more than 5 metres of another building belonging to your house.
  • Overshadows a neighbour’s window that has been in place for 20 years.
  • In a conservation area or is part of a listed building


Permitted Development only applies to individual dwellings, so alterations to apartments cannot be undertaken under Permitted Development. 

Basement developments are viewed by Local Authorities as potentially toxic and there’s no easy path to securing consent. In some London boroughs, a basement build must satisfy  many hundreds of guidelines, requirements and specifications before any consent can be forthcoming. Here’s some more information on planning applications for basements

Let’s take a loft conversion as an example. You’ll need to get planning permission if the conversion:

  • Includes a roof extension or a dormer window that is going to extend beyond the plane of the current roof slope and is facing a road.
  • Makes any part of the property higher than the highest part of the existing roof.
  • Increases the volume of a terraced house by more than 10% or 50 cubic metres (whichever is greater).
  • Increases the volume of any other kind of house by more than 15% or 70 cubic metres  (whichever is greater).
  • Adds more than 40 cubic metres to the volume of a terraced house.
  • Adds more than 50 cubic metres to the volume of any other kind of house


To offer an insight, a standard planning application requires a number of documents in support of an application, including but not limited to:

  • Architectural Designs Plans, elevations and sections providing detailed design drawing  information on the proposal.
  • Planning Statement  A statement demonstrating how the proposal accords with the emerging planning policies allied to basement development.
  • Heritage Statement A statement aiming to explain the minimal impact of the proposal upon the historic building or conservation area.
  • Structural Design Plans, sections and calculations detailing the structural integrity of the proposed design (necessary for Building Regs approval).
  • Design & Access Statement An outline of the design principles and concepts that have been applied to the proposed development.
  • Construction Method Statement An outline of the approach to managing the construction works, including specific comments on; site establishment, logistics, environmental management, noise and dust control.

In addition to the above and dependent upon the extent of the proposed design on neighbours there may be a number of other specialist reports required.


It’s so important to understand the specific restrictions applying to your building, area or planning authority.  Our expertise lies in over 30 years experience of  securing the required consents across all the London Boroughs and we can do this for you.

Once you have secured planning consent, you will be required to submit technical design information to secure building regulation approval.  This is required to show that the works for which you are undertaking, fully comply with the statutory requirements of the building codes.

We know the planning regulations inside-out and have years of experience in obtaining successful planning permission outcomes for our clients. 

Regardless of whether you need formal planning permission, all works carried out to your property must be fully compliant with the statutory requirements of the building codes.  Dependent on the situation you may need to apply for Building Regulation approval.  Again we can undertake this for you.

 It’s what we do.  And we’re good at it.