Rules for house extensions in 2022
There have been a number of changes to house extension rules in recent years, with the government introducing new legislation that could make easier for you to expand your living space. But if you aren’t able to keep up-to-date with the latest developments, knowing what is and isn’t allowed can seem confusing. Here we explain the rules for house extensions in 2022 to help you plan your next move.
What homes require planning permission?
If you live in a flat, maisonette or listed building, you will require planning permission before any changes can be made. This also applies to some new developments and some houses built before 1948. If your property is located in a conservation area, there is a good chance you will have to seek planning permission, although you should also consult with the local authority to be sure.
What projects do not require planning permission?
The changes most recently introduced by the government will you allow you to build the following without applying for planning permission, providing certain guidelines are met:
Rear extensions
For attached houses, a rear extension cannot extend more than 6m beyond the current rear wall. The limit is 8m for detached houses. The extension must be less than 4m in height (if within 2m of the boundary the maximum height is 3m). You must use similar materials as the current home and the extension has to comprise of less than 50% of the land surrounding the property.
Side extensions
Side extensions are not permitted to face a highway and should be built using similar building materials as the current house. The size cannot be more than 50% of the original property’s width, and less than 50% of the surrounding land. The height cannot be more than 4m, or 2m if built within 2m of the property boundary.
Two-storey extensions
A two-storey extension must be less than 50% of the house width and cannot feature windows in the roof slope/wall of the side elevation. Similar building materials must be used and terraces cannot be more than 3.5m higher than the next tallest terrace. The extension must also not take up more than 50% of the surrounding land.
Loft conversions
Similar building materials have to be used, and for detached and semi-detached houses there is a maximum volume allowance of 50 cubic metres. There cannot be any windows in a roof slope or wall forming a side elevation. Dormer walls must be set back by a minimum 20cm from the current wall face, and if windows are below 1.7m from floor level they should be non-opening. The principal part of the dwelling must have a roof pitch as the same level as the existing house.
Building a new storey
If you are building a new storey you cannot add windows in a roof slope or wall of the side elevation. Two additional storeys can be built on existing multi-storey properties, and living areas such as a loft extension would not be classed as a storey. The extended property must have a maximum height of 18 metres and terraces cannot be more than 3.5m higher than the next tallest terrace.
Things to be aware of
Not requiring planning permission doesn’t mean there aren’t any regulations that have to be followed. In the first instance, working with a qualified and experienced architect will ensure that your designs meet the requirements discussed above. If you go ahead without verifying your designs, you run the risk of being fined by the local authority or even demolishing the extension. Other requirements you have to be aware of include:
Party wall agreements
Build over agreements
UK building regulations
There may also be other areas that need to be reviewed before any work begins. This is where the true value of hiring an architect comes in play, as they can help you ensure everything is in place before structural changes begin.
Benefits of hiring an architect
By law, you do not have to hire an architect for your project. While they add to the expense of building an extension, their participation in the project can prove invaluable. Not only can they help you deal with the many complicated rules and regulations that are involved in any domestic building work, but they can also manage the entire project from start to finish.
Getting approval to build an extension can be tricky, especially if you have not taken on a project of this size before. Using an architect enables you to tap into their planning and technical expertise so you can save money and build the best possible living space for your home. Practicing architects in your area will also have a number of local contacts of which can be utilised and deployed throughout your project.
How to build a home extension
If you are thinking of building an extension to your home in Cambridge, the Tereyn team can help you plan and avoid costly mistakes so you make the most of your budget. Call us today on 07984 760 920, send us a message here or email us at info@tereynarchitects.com and we’ll get right back to you.
