Do Loft Conversions Need Planning Permission?




do loft conversions need planning permission

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Most loft conversions fall under the permitted development rules so do not require planning permission. However, if your conversion rises above the current ridgeline of the roof, you live in a conservation area, or are significantly increasing the footprint of the property, you will have to apply for planning permission.

Ok, that may seem a little confusing but the good news is that when you are converting your loft it is not usually necessary to obtain planning permission. The vast majority of homeowners will not have to apply for planning permission when they convert their loft.

Unfortunately, that doesn’t mean you can just whip out the toolbox, pass the sledgehammer to your partner and get stuck in.

Not just yet anyway.

Although planning permission is unlikely to be needed there is still some red tape to wade through and regulations to adhere to as all loft conversions, apart from some light storage solutions, must make sure they comply with the building regulations.

And, if all that wasn’t enough, there is also the Party Wall Act to take into consideration. So, planning permission, a party wall agreement, and building regulations approval. It’s a lot to take in.

Confused? Don’t be.

You can find further information here on the Party Wall Act and the loft conversion building regulations. But we’re talking about planning permission now so Let’s loop back to the beginning. Planning permission for loft conversions is ordinarily only required under the following conditions:

*Any addition to the roof slope faces a highway.
*If any part of your proposed conversion will be higher than the existing roof line.
*Your home is a listed building.
*If the original house is to be increased by 50 cubic metres (40 cu m for terraced houses) or a total in excess of10% in both cases.
*You are lucky enough to live in a national park or area of outstanding natural beauty.

Those are the bullet points but let’s put some more meat on the bones.

Highway facing roof slope

If your intended loft conversion includes a dormer, or any other alteration to the roof, which faces a highway then your project will require approval under the planning laws. But it is highly likely that permission will be refused.

However, should the dormer be facing the rear of the property, i.e., away from the highway, then it is usually not necessary to obtain planning approval.

Much depends on the attitude of the local authority. They frown on the large box dormers which sprung up like a plague during the 1980s (and were actually excluded from Permitted Development prior to 1990) but are relaxed when it comes to the dormer being at the rear of the house.

Side dormers are usually a source of contention and, if you are determined to go down this route, you will need to consult the local authority as planning approval is often required in those circumstances.

At this point it should be pointed out that, with typical ambiguity, the definition of a ‘highway’ can not only include roads but also lanes and footpaths.

Building above the existing roof line

It is explicit in the regulations that if your loft conversion project features a dormer or structure which will extend above the existing roofline than a planning application will need to be made.

If your conversion will feature only flush fitting roof-lights than there isn’t an issue here but structures such as balconies or dormers will have to be considered carefully.

The first thing to do is to establish the highest part of the roof. This should be reasonably straight-forward as the ridge, or apex, of the roof is by definition usually the highest point.

An exception may occur if the roof has been re-tiled along its ridge, thus increasing its height, or if a parapet wall has been built.

However, the rule is very much that the apex of the roof provides its highest point and, as long as any new structures are built below that point, then approval will not be required.

Listed buildings

It will surely come as no surprise that attempting a loft conversion in a listed building will be fraught with difficulties and strangled in red tape.

For the vast majority of us this section will have no relevance but, should you live in such a building, then your project will not only need to meet the planning and building regulations but you must also obtain listed building consent.

Listed building consent will apply even if the proposed conversion is purely an internal procedure with no roof-lights. The only good news is that a listed building consent application is free.

Increasing the size of the original house

The Town and Country (General Permitted Development) Order (1995) rules that the maximum allowance for extending space within the original house is 50 cubic metres (40 cu m for terraced houses) or 10% in both cases.

The original house, or ‘dwellinghouse’ as the legislation states, is the state in which the house stood on July 1, 1948, or when it was first built. Whichever is the later date. The volume of the original house includes the roof space and any subsequent extensions.

So, if your property already has, for example, a ground floor extension, then, under the planning permission regulations, the size of that development will count towards the allowed space in addition to the space required for the loft conversion.

In other words, if your house has a kitchen extension of 20 cubic metres then only 30 cubic metres would be available for the loft conversion.

Calculating the volume of the original house is done by measuring the external dimensions and should include any extensions, porches etc.

You live in a national park

For obvious reasons the scope of permitted development in conservation areas is much more restricted than in most towns and cities.

As a general rule of thumb, if your property is located in a designated conservation area then, under the planning laws, your project will require approval from your local planning authority.

Although some, and it is only some, local authorities will allow conversions with windows which fit flush to the existing roof, there is no way that you should undertake any roofing work without consulting the council.

What about the building regulations?

Although planning permission is unlikely to be needed your project will need to conform to the building regulations enforced by the local council building control department.

But, as we said at the top of the page, the planning laws are now very relaxed when it comes to adding any kind of extension to your property.

But it is also important to realise that the planning regulations are completely different to the building regs.

So, what exactly are the building regulations?

Good question. Quite simply they are the minimum allowed standards of construction and design as laid down by the government. Building regulation approval is given, or declined, by the local authority.

And, naturally, there is a fee to play and application forms to be filled out. Come on, you didn’t really expect anything else, did you?

The bottom line is that your loft conversion cannot go ahead until you have submitted plans to the local authority and have had your application approved.

Please don’t be tempted to begin work without the necessary approval. You could end up being hit rather hard in the pocket.

The major tenets of the building regulations that you are required to comply with are:

The floor must be strong enough to cope with the extra stress and weight of the loft conversion. This is a no-brainer. Even basic storage solutions will probably require floor strengthening and other types of loft conversion will need new floor joists.

The stability of the structure, including the roof, is not endangered. Again – pretty obvious.

Fire safety. Hugely important. The building regulations insist that loft floors and walls must be able to resist fire for thirty minutes. And of course you’ll need mains powered smoke alarms and escape windows in event of a fire.

The stairs to your proposed loft conversion, possibly the most important feature of your project, must be designed to comply with safety standards. And there is sound insulation to take into account too.

Finally, if you are planning a do-it-yourself loft conversion then your local architect or draughtsman will draw up and help you to submit your application for building regs approval or, if you are employing builders who are loft conversion specialists, then they should be able to obtain the required approval for you.

Make sure this is included in the price they quote you for the build.

So, to sum up. Building regs approval is always needed but the big changes in the permitted development rules now means that, for the vast majority of us, we no longer really need to think about the myriad aspects of planning laws. Which is pretty good news all round.

Some notes on permitted development

However, should you decide to include a veranda, balcony or raised platform as part of your loft conversion you will have to apply for planning permission.

And, in order for your project to remain with permitted development rights and avoid the application for planning permission, side windows must be glazed with obscured glass if the openings are 1.7m higher than the floor.

A roof extension, apart from hip gable ones, must also be set back 200mm from the eaves. In designated areas, which include national parks, World Heritage sites and areas deemed as being of outstanding beauty, roof extensions will not be permitted.

Obviously before drawing up plans for any home extension, it is obviously in your own interest to check with your local authority what is and what is not permitted in order for it to remain a “permitted development.”

It should also be understood that the regulations for other buildings such as flats and maisonettes are different, and that this should be taken into consideration when thinking about the planning laws for your property.

Do loft conversions need planning permission – FAQ

Here’s quick answers to the most common questions we hear about loft conversions and planning permission.

planning permission form that needs to be filled out when making a planning application for a loft conversion
Don’t be put off by the paperwork

How much does applying for planning permission cost?

Loft conversions aren’t cheap, so it does sting a little to have extra costs. Unfortunately, you do have to pay when you make an application for planning permission. It usually costs between £200 to £230 though costs in some cases can reach £1,000. Which will hurt even though it’s a necessary expense. But fees can vary from one region to another.

How long will it take to get planning permission for my loft conversion?

It’s a surprisingly quick process. Loft conversions aren’t usually complex projects, and you should get a decision within eight weeks of submitting your application.

How long does full planning permission last for?

Sometimes, despite all our planning and having the best intentions, projects get delayed. Hopefully that won’t be the case with your loft conversion.

But if you’re granted planning permission and then your project is delayed for any reason, your approval normally lasts for three years. You don’t have to complete the work within those three years, but the building project must be started within the timeframe.

Do dormer loft conversions require planning permission?

No, a dormer loft conversion, as long as the dormer windows are on the rear facing slope of the roof and will not exceed the height of the existing roof line, are allowed under the permitted development limits, and will not require planning permission.

Do hip to gable loft conversions require planning permission?

Hip to gable conversions are allowed under the permitted development rules so, subject to the usual caveats (list building etc) they don’t require planning permission.

Do mansard loft conversions require planning permission?

Unlike other loft conversions, converting a mansard roof involves making drastic changes to the structure of the roof. So, if you’re planning a mansard loft conversion, you will need to apply for planning permission.

Do storage loft conversions require planning permission?

No, if you’re simply laying down boarding to increase storage space and accessing the loft via a ladder and hatch then you don’t have to apply for planning permission.

To check the latest official regulations it’s a good idea to visit the government’s planning portal.

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