Considering a loft conversion? Use the drop-downs to find out more.


A loft conversion is where the existing roof space in a house is converted to provide more living space, often a bedroom with ensuite or home office.

loft conversion

It will normally involve the installation of a dormer window to the roof. More significant physical alterations – e.g. raising the roof to create another storey – would normally go beyond what could reasonably be considered “conversion” of the loft. 


The short answer is, it depends. Basically, there’s two main routes to getting your domestic loft conversion. The first route, using permitted development rights, doesn’t require you to apply for planning permission. However, if your site doesn’t have permitted development rights or your loft conversion is bigger (or different) than the permitted development rules allow, you must apply for planning permission.

Route 1: Permitted development rights

If your house benefits from permitted development rights, you will have options to convert your loft without any need for planning permission. Click the button below to find out more about what sites have permitted development rights.

You can also find out more about the permitted development rules for domestic loft conversions by clicking the button below.

In addition, the government has published their own guidance on householder permitted development which you can access for free here:

In order to be permitted development, a loft conversion must:

  • not increase the height of the house
  • not add anything to the front roofslope (such as a dormer)
  • not increase the total cubic content of the roofspace by more than:
    • 40 cubic metres for a terraced house
    • 50 cubic metres for any other house
  • be constructed of materials similar in appearance to the existing house
  • not contain side windows unless they are obscure-glazed and non-opening
  • retain a gap of at least 0.2 metres between the edge of any dormer and the existing roof eaves.

This list is non-exhaustive.

If your loft conversion complies with all permitted development rules, you are not obliged to submit any form of planning application and you can get on with building works straight away. However, we strongly advise that you apply for a lawful development certificate prior to commencing works. Click on the button below to find out why.

You can also find some more general information about lawful development certificates – including what they are and how to obtain them – by clicking the button below.

Route 2: Planning application

If your site does not benefit from permitted development rights or your loft conversion does not comply with all the permitted development rules, you’ll need to submit a householder planning application to your Local Planning Authority (this is normally your local council). Find out more about submitting a planning application by clicking the button below.

Your local council will consider your loft conversion application in the same manner as any other application for a domestic extension. Click the button below to find out more about domestic extensions, including how they should be designed and what issues the council will take into account when making their decision.

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