Do you need planning permission for a loft conversion? Not always say the experts

One of the most commonly asked questions by homeowners keen to expand their houses is 'do you need planning permission for a loft conversion?' And, in many cases, they are pleased to learn that they don't, in fact, need to spend time making an application and waiting for a decision.

All kinds of loft conversion ideas are brilliant ways to add space without extending the footprint of a house - plus they can add to the value of a property and are usually cheaper to complete than an extension.

'The need for planning permission for a loft conversion can vary based on the type of property and its location,' says Rob Wood, managing director at Simply Loft.

Here, we explain everything you need know about planning permission for loft conversions.

Rob Wood

Rob and Helen Wood set up The Simply Construction Group in 2008. They sought to professionalise the stressful and disorganised construction industry. Initially setting up the brand Simply Extend, the Simply Construction Group has grown to include Simply Loft, Simply Basement and Simply Architects.

Do you need planning permission for a loft conversion?

There are many instances where full planning permission will not be required in order to convert a loft.

'Loft conversions in many areas of the UK can often be carried out without the need for planning permission, falling under 'Permitted Development' rights,' explains professional planning consultant Simon Rix, founder of Planix.uk.

'To ensure your loft conversion falls under Permitted Development, it’s important to first verify that your home is eligible, taking into account any previous developments or extensions, and whether your home is located in a designated area where such rights don’t apply,' continues Simon.

Don't just assume your project will fall within your Permitted Development rights because your neighbour didn't have to apply for planning permission.

'Certain criteria must be met to qualify, such as ensuring the conversion doesn’t exceed specific size limits or alter the roof's highest point,' explains Simon Rix. 'Even if your project meets these criteria, it's advisable to apply for a Lawful Development Certificate from your local council to confirm that planning permission isn't required. This certificate not only provides peace of mind but also serves as a valuable document for future property transactions.'

If you have established that your home isn't in a designated area and you are not living in a flat, you still need to meet the size guidelines for loft conversions:

Does my loft conversion fall under Permitted Development?

• Size: If you live in a terraced house, your design should not increase the size of your roof space by more than 40 cubic metres. In other types of houses, this increases to 50 cubic metres.
• Roof height changes: You can't make the existing roof any higher than it is already without planning permission.
• Chimney alterations: Without planning permission you can't add, alter or replace any existing chimneys or flues.
• Window placement: Under permitted development, any new windows to the side of the conversion must be obscured.
• Positioning: Unless you are carrying out a hip to gable loft conversion, your new addition will have to be set back a minimum of 200mm from the eaves. You will also not be allowed to extend the roof more than any existing roof slope that can be seen from the principle elevation.
• Balconies: Balconies, with the exception of Juliet balconies, cannot be constructed under permitted development.

Simon Rix

Simon Rix is a professional planning consultant, who began his career working in local government in the 1990s. He was a council officer and later an elected councillor, so he knows how the planning system works from both sides. He went on to set up Planix.UK Planning Consultants Ltd; a consultancy company that advises self builders, home extenders and those taking on small to medium-sized building projects on planning permission.

When will a loft conversion need planning permission?

When it comes to how to plan your loft conversion, it is important to be aware that while certain conversions and extensions will fall under PD rights, there are cases when a design won't meet the required criteria.

'For houses in designated areas, such as conservation areas or those considered listed buildings, additional planning consent is usually required,' explains Rob Wood. 'These areas often have stricter regulations to preserve the character and appearance of the local neighbourhood and community.'

'The design itself must adhere to specific limits regarding the size, materials used and impact on the roof structure,' picks up Simon Rix. 'If your project involves significant alterations, such as with a mansard loft conversion or the addition of a balcony, a full planning application will be necessary. Using a good planning consultant can help navigate these complexities and avoid costly errors, ensuring your project proceeds smoothly.'

'It is important to consult your local authority’s guidelines along with speaking to a professional or an architect about the size and type of your loft conversion,' points out Rob Wood.

How do you apply for planning permission for a loft conversion?

If you find that planning permission is going to be needed for your loft conversion, you can make an application through the Planning Portal. You will need to bear this in mind when budgeting for your loft conversion costs as you can expect fees of around £250 and a service charge of £70.

FAQs

Does my loft conversion need building regulations approval?

Regardless of whether your loft conversion needs planning permission or not, it will still need to comply with building regulations.

'Building regulations cover aspects such as fire safety, structural stability, insulation, ventilation and accessibility,' explains Rob Wood. 'Compliance with these regulations ensures that the loft conversion is safe, energy-efficient, and in line with established building standards.

If you use an architect or specialist loft conversion company they will help you ensure your project meets all the requirements of building regs.

Do I need a party wall agreement for a loft conversion?

If your loft conversion involves any walls that are shared with another house, you should get a party wall agreement. This is sometimes the case when a conversion requires a new structural beam to be inserted into the shared wall.

'As well as planning permission for your loft conversion, you’ll also have to consider a party wall agreement before work can begin on your project,' advises Rob Wood. 'This is an agreement amongst neighbours if you share a wall or are close in proximity to your neighbouring properties that the construction is accepted by the neighbour.'

You can either serve a Party Wall Notice to your neighbour(s) yourself, or use a Party Wall Surveyor.

Loft conversion storage

A loft conversion won't be right for everyone and in some cases building an extension - either single or double - is the only way to get the additional space you need. Even if you decide not to convert your loft into habitable space, you should still make sure it is properly insulated in time for winter.