Do you need planning permission for a loft conversion?
15 May 2019 | Knowledge Hub
For most loft conversions, planning permission is not required. That's because they generally fall under your permitted development rights. That said, you will need to get planning permission if your plans exceed certain limits and conditions, such as extending or altering the roof space beyond its current limits. You'll also have to follow strict building regulations, which are in place to ensure that building work is done safely. In this article, we'll discuss both of these important topics.
Loft conversion planning permission
When it comes to navigating the world of planning permission, it can be easy to get confused. Whether or not you need planning permission depends on the kind of works you are carrying out, and the extent of these works. Read on to learn whether your loft conversion plans fall under permitted development and find out what you need to know about planning permission.
When does a loft conversion fall under permitted development?
To find out whether or not you need planning permission, it’s always wise to get an architect or builder to confirm it for you. That said, a loft conversion falls under permitted development and does not require planning permission as long as it meets the following conditions:
The new loft space won’t be larger than 40 cubic metres for terraced houses and 50 cubic metres for detached and semi-detached houses.
The loft conversion doesn’t extend beyond the plane of the existing roof slope at the front of the house (principle elevation).
The loft conversion does not extend higher than the highest part of the existing roof.
The loft conversion does not include any verandas, balconies, or raised platforms.
The loft conversion is made using materials that are similar in appearance to the rest of the house.
Any side-facing windows must be obscure-glazed (to stop people seeing in and out).
Any side facing windows must be at least 1.7m above the ground.
Your home is not located in certain designated areas, including national parks, Areas of Outstanding Natural Beauty, conservation areas, and World Heritage Sites.
A roof extension, with the exception of hip-to-gable extensions, must be set back at least 20cm from the original eaves.
A roof extension must not overhang the outer wall of the original house.
For any alterations that exceed the limits and conditions listed above, you will need to apply for planning permission from your local authority. Fortunately, this can now all be done online, and you can apply to every local authority in England via the planning portal. If you're in Scotland, you can also apply online using the ePlanning website. Those in Wales can access the Welsh planning portal, while homeowners in Northern Ireland can use the indirect website.
For further information on permitted development, please read the government's technical guidance on permitted development rights for householders.
Please note: The limits and conditions for loft conversion permitted development above only apply to houses, and planning permission will have to be sought if you live in any of the following:
Houses created through the permitted development right to change use
Other non-dwelling buildings
Homes in areas where there may be a planning condition or other restriction that limits permitted development rights
How much does planning permission cost?
If you do have to submit an application for planning permission, there will generally be an application fee that must be paid. Planning permission costs vary widely, starting at £206 for alterations and extensions made to a single dwelling house and increasing from there. For certain applications, such as listed buildings or those that are to be demolished in a conservation area, no application fee is required. To find out exactly how much you might have to pay, you can use the Planning Portal’s handy fee calculator.
How long does planning permission take?
Your local planning authority is obliged to make a decision on your planning application as quickly as possible. Local planning authorities should not take longer than eight weeks to make a determination on a straightforward planning application, 13 weeks for a particularly large or complex application, and 16 weeks if an Environmental Impact Assessment must be carried out.
Loft conversion building regulations
Regardless of whether you need to seek planning permission for your loft conversion, you will still need to follow the relevant building regulations outlined on the Government website, and seek building regulation approval via the planning portal. Building regulations are important, as they ensure that any loft conversion is structurally strong and stable, stairs have been installed correctly, and that it would be safe to escape during a fire. What building regulations you will need to be aware of depends on the type of conversion you are planning:
• Creating a storage space: If you want to convert your loft into a storage space, you may need to seek building regulation approval. Typically, the timber joists that act as the "floor" of your loft (the ceiling of the rooms below) won't have been designed to support any kind of significant weight. An excessive weight on these joists can load them beyond their design capacity, and you will require building regulations approval to ensure their safety.
• Creating a liveable space: If you want to convert your loft into a liveable space and use it as a normal part of your home, then you will need to seek building regulation approval. Full loft conversions typically require a wide range of alterations to be made, which could affect the original structural integrity of the building. If building regulations are not followed, any conversion could put both the building and its occupants at risk.
Building regulations breakdown
Here's a breakdown of some building regulation considerations that you may have to make. Please note that this is intended as a basic guide and you should always consult a builder or your local authority before carrying out any works.
Load-bearing walls: You need to think about how new loads will be supported by your existing walls. If new floor joists are needed, they must be supported by an existing wall that goes all the way down the house to a foundation.
Removing rafters: To bring light into your loft, it is likely you will need to cut an opening in the existing rafters to install roof windows, which will then need to be supported by installing new timbers. The roof will need to be reinforced in order to take this additional load.
Floor joists and beams: Your existing ceiling joists likely won't be able to support the weight of a loft conversion. New floor joists that are larger than your existing ones will typically need to be installed to take the new load. Sound insulation: Sound insulation is required between habitable rooms and, in terraced and semi-detached houses, you may need sound insulation between your loft and your neighbours' lofts. If this is necessary, the existing party wall will need to be upgraded.
Fire safety:Loft conversion fire regulations state that you'll need to install additional fire protection between the home and loft, provide smoke alarms within the stairway at each level, and install an escape window at least 45cm wide.
Staircases: If your loft conversion will be habitable, then you'll need to make sure you have a staircase that can act as a fire escape. If there is not enough space, it may be possible to install a smaller, space-saving staircase, but retractable ladders will not typically be accepted. Loft ladders are only suitable as a means of accessing the roof for storage purposes or to carry out repair works.
You now know the basics of what you need to consider when converting your loft. If in doubt, we would always recommend seeking the advice of an architect or builder who will be in a better position to assess your particular situation.