What are the rules and regulations for loft conversions?

We regularly advise homeowners considering home improvements rather than moving. People want to increase the size of their current home rather than taking the next step on the property ladder, or they might want to push up the value of their property.

A loft conversion is a great way to add a bedroom to your property without increasing the footprint or losing garden space with an extension. Generally, in the southeast and London, you would need to spend at least £35-40,000 to complete a loft conversion, depending on size and complexity. 

Setting the budget is the easy part though. Planning a loft conversion can be a daunting task for many. We hear so many questions relating to planning and building regulations, party wall agreement and more. Here, we answer the most common questions about loft conversion rules and regulations.

Do I need planning permission for my loft conversion?

Many loft conversions can be built under the ‘Permitted Development’ rules, which specify the sizes of additional space that can be built without planning permission.

You can also have a dormer loft conversion to increase height in your conversion, as long as they don’t sit higher than the highest part of your existing roof or extend forward of the roof plane at the front of the house. However, if these are visible from the highway, consent may be required.

If you are having a mansard loft conversion, one which is typically built to the rear of your home, has a horizontal roof and almost vertical back wall, you would usually need to seek planning permission (as it alters the roof structure to a 72-degree angle).

You must always double check the need for planning consent with your local planning authority. If you live in a conservation area, a listed building, already have extensions to your house, or if there are specific rules in your area, you might need to apply for planning.

Do I need to get permission from my neighbour before converting my loft?

You don’t need permission from your neighbour for your loft conversion, but you may need to have a Party Wall Agreement if you’re converting a loft in a terraced or semi-detached property. Usually, the work will affect the party wall as steelwork (loft conversion steels) will need to be installed, or the wall may need to be raised to form a dormer. If the party wall is affected, you must notify your neighbour under the Party Wall etc Act, which states you must give two months’ notice. Your neighbour cannot use the Party Wall Act to prevent you from doing your work, but it is essential that the right notices are served and process followed, otherwise your neighbour can delay your work until the right agreements are in place. These delays could be long and costly. If your neighbour agrees to the work, you must get that agreement in writing. More about Party wall agreement and loft conversions.

Will my loft conversion need a structural survey?

If you use a Chartered Building Surveyor, architect or a loft conversion company, they will start by carrying out a detailed survey of your loft and walls to check for any potential problems and assess the structural work that is needed. If you use your own builder, you should ensure that the structure is properly assessed to avoid problems when the build is underway. You can use a chartered surveyor to advise you, and we can even project manage your loft conversion for you. Generally speaking, older roofs can be easier to convert than modern roofs with complicated factory-built roof trusses. It can be done, it’s just harder and more expensive. Any structural alteration work and steel supporting beams will need to be properly designed and calculated by a qualified Structural Engineer.

What building regulations must I follow when converting my loft?

If you are having a loft conversion, building regulations must be complied with. Your architect or designer will advise you about this, but you will probably follow a process known as ‘building notice’ where the local authority is notified of your work and inspects at key stages. If you don’t get building regulation approval, the local authority may take enforcement action and your property could be harder to sell as surveyors check for this when they inspect a property for a purchaser. The building inspector will be interested in matters including the structural work, fire separation and control, thermal performance, staircase and windows. Building regulation approval confirms the safety and structural adequacy of the work. Without this, not only will the conversion be unlawful, it may also be dangerous.

What about health and safety?

Your contractor must follow all Health & Safety legislation. Just because it’s a small residential job, it doesn’t mean the requirements are different. Your builder should be fully aware of health and safety on building sites and should also have relevant insurances. You should also consider insurance too.

Are there rules on where the stairs to my loft must be?

As long as the project meets building regulations and adheres to health and safety law and planning, then the stairs can be fitted where they best meet the project’s needs. However, you should be aware that there mustn’t be more than 16 stairs in a single flight; head height must be at least 2000mm for the length of the flight; and the pitch or slope should be 42 degrees. There must be a fire door at either the top or bottom with a set distance (usually 400mm) between the door and top/bottom tread. More about the rules relating to staircases can be found in the article, Staircases: Is it the most taken for granted part of the home?

Can I have an en-suite shower/bathroom in my loft?

You can put what you like in your existing loft space as long as it’s feasible. It could be a bedroom with a small en-suite and no shower if the height doesn’t allow, or if you have a dormer fitted then it’s likely a shower will fit. Remember though, a loft conversion doesn’t automatically have to be a spare bedroom. It could be a relaxing lounge area, a home cinema, a playroom, or a study. We’ve even seen occasions where a kitchen has been installed in a loft conversion!

For advice on surveys for loft conversions and help with Party Wall Agreements in London, contact us today using the form below.

(Note: The information in this article is for guidance only. There is no substitute for advice specific to your situation. If this is an old post, the law may have changed since it was written.)