How to Plan a Loft Conversion: Your Planning Guide




planning a loft conversion

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A loft conversion is a big project which needs a large investment. Which is why you need to plan it carefully.

What will you use the space for? Which builder will you use? Do you need planning permission? How will you comply with the building regulations? How much will it cost? All these questions need to be answered when you plan your loft conversion.

Initial planning

Most of your initial planning should focus on three things; what you will use the space for, choosing a builder, and how much the project will cost.

We’ll discuss what you can use the space for in more detail later in the article but you probably already have a fair idea. If your family is expanding the loft is the perfect place to add more bedrooms or if you need an office space at home, again you can make use of the loft. Maybe you want somewhere to enjoy your hobby – the loft makes a fantastic hobby or craft room.

Choosing the builder is a massive decision. And one which you should think long and hard about. Do lots of research, look at reviews, get at least three quotes and insist on seeing examples of previous work by any builder you shortlist.

One of the big questions you’ll have is how much does a loft conversion cost? This does vary depending on where you are in the country and the type of conversion you build. A dormer in London will cost significantly more than a similar project in Hull.

How to plan a loft conversion

Before you can begin to plan your project in detail you first need to make sure that your roof space is suitable for converting into a new loft room. To do this the first thing you must do is carry out a loft survey.

Basically, this means checking the existing headroom in the roof space and checking to see if extensive structural alterations are going to be necessary.

Most lofts within UK properties can be converted; though some are much easier to convert than are others. If your property was built prior to 1960 or has a steeply pitched roof then there is nothing to worry about and you should be able to convert a loft quite easily.

But, if your home was typically built between 1962 and 1972 (ish) then you may have problems because the roof is likely to have a very shallow pitch. The problem with a property having a very shallow pitched roof is that, to plan a loft conversion successfully, that roof will have to be raised.

Structurally, this isn’t such a big deal but the problem with raising the property above the existing roofline means that planning permission must be sought from the local authority. This can of course lead to all sorts of disputes, delays and expense.

Another thing to consider with such a property is that even if planning permission is granted and the roof can be easily raised the loss of first floor space for the new staircase may mean that no extra living space will be actually achieved with a loft conversion. Which would make the whole thing a waste of time.

Do a loft survey

The key question here is ‘how much headroom is available?’

Without being too obvious; if you can’t stand upright in the roof space then it is highly unlikely that you will be able to plan a loft conversion without considerable expense being added to the project. Basically, it may well be economically unviable.

If, however you can stand upright, and even better raise an arm above your head, then you’re in business. Really you should be looking for a minimum amount of headroom of 2.2 to 2.3 metres. Don’t worry if this headroom is only available in the centre of the roof space; by installing even a small dormer this space is massively multiplied.

Other things to look for

While you are checking out the headroom in the roof space don’t forget to have a look at the general state of repair of the roof and the walls. If any work needs doing, for example re-pointing, then it may as well be done at the same time as you convert a loft.

Aside from the headroom issue the other main thing you are looking at is the type of roof you have.

A rafter and purlin style roof

A purlin and rafter roof is usually considered perfect for loft conversions and headroom shouldn’t be an issue if the house has this kind of roof so it isn’t essential to include a dormer in your planned loft conversion.

Of course, you may wish to include a dormer in your design anyway – by doing so you will create even more room and broaden the scope of your loft conversion.

A trussed rafter style roof

A trussed roof may require some structural alterations such as the roof height being extended. If your roof is of this type then it complicates matters a little when you come to plan a loft conversion but it is not an insurmountable obstacle.

More things to consider

When planning a loft conversion there are a few essential factors to think about before committing the project to paper ranging from permitted development issues, design and even your neighbours.

The neighbours and party walls

It may seem a bit early to worry about Mrs Next Door, and you may not have the inclination to worry about her anyway, but it’s always best to get the neighbours onside as soon as possible. Especially if you share a party wall.

Although the actual building of loft conversions shouldn’t inconvenience the neighbours too much there will still be unavoidable noise and possibly traffic disruption.

No one likes to hear a gang of builders hammering, joking and chatting first thing in the morning so keeping the neighbours sweet in the early stages will store up some goodwill for the future.

Another reason to keep the neighbours informed and up-to-date with developments is that you may well need their co-operation when the building work begins if a party wall is involved or if you have to make a full loft conversion planning permission application.

If your property is semi-detached or part of a terrace you will need a party wall agreement with your neighbour. This protects the neighbour from your work having a negative impact on their property but also protects you in the event of any dispute further down the line involving claims about damage.

Permitted development

With the change in the permitted development laws, it is important when planning a loft conversion to remember that most loft conversions no longer need planning permission though the volume cap still exists.

The volume cap means that loft conversions are only allowed to add up to 50 cubic metres to the roof space of a detached or semi-detached house, with only 40 cubic metres allowed to be added to terraced properties.

Another point to consider is that the permitted development of dormer designs has changed in that they will not be permitted on any roof that fronts onto a highway and that they should be set back from the eaves by a minimum of 20 cm.

What hasn’t changed is that any loft conversion, or dormer extension, must not be higher than the existing roof ridge of the property.


The best part of planning a loft conversion is coming up with the final loft design or concept for your new room.

The most popular loft conversion in the UK is adding an en-suite bathroom but we discuss all the possibilities in the design section of the site. However, one vital aspect that you must take into account no matter what the final room will be, is that the location of the loft stairs must be absolutely right.

It must be remembered that even though you are creating more living space in the loft you will lose a significant amount of space on the first floor when you install the loft stairs.

If there are space restrictions on the existing landing then one of the bedrooms will probably have to be sacrificed in order to fit in the new flight of stairs to the loft.

Of all the aspects of planning a loft conversion the location of the staircase is the single most important factor to consider and to get right.

Planning issues

When considering the planning of your loft conversion there are some often overlooked things to consider before finalising your project.

Apart from the building regulations another factor to consider before undertaking a loft conversion is the small print on your mortgage agreement.

If your property is mortgaged then, when planning your project, it may be necessary to inform your lender. In the vast majority of cases there won’t be an issue but, because the bank or building society have a financial interest in the property, they may need to give their formal consent for the work.

As well as pouring through the small print on your mortgage agreement you will also need to consult your building and /or contents insurance policy when planning your conversion.

Most policies make it mandatory for the householder to notify the insurance company of any major building work to be carried out on the property.

Informing the insurance company of your intentions will negate any potential problems with potential claims at a later date. And, in the case of building insurance, the policy will need to be amended once the project is completed to take into account the extra space created by the loft conversion.

Local authority covenants need to be considered – especially if your house was purchased from the local council under the right-to-buy rules.

Restrictive covenants are conditions which govern how the land / property can be developed and sometimes preclude loft conversions.

Such a covenant is unlikely in most cases but if your property is a former council house it is worthwhile checking the Land Registry to make sure no such restrictions apply to your home.

One other thing to consider, unlikely as it may seem, are bats!

Be warned.

If your roof space is home to a bat colony then, by law, it is illegal to disturb them. Hopefully though, unless you live in an Adams Family style mansion, you won’t have to worry about bats. If, however, you feel the need to research the issue, have a look at the Wildlife and Countryside Act (1981).

It is unlikely that any of the above considerations will need to be taken into account when thinking about your loft conversion but you should certainly inform your mortgage lender and insurance company of your intentions.

Project managing your loft conversion

Although you almost certainly won’t be building your new loft extension yourself there is still lots of hard work in front of you.

No matter which builder you choose, or how hands on your role, there is still going to be plenty of project management to keep you busy before, during and after the build.

When it comes to converting the loft there are only a few options to choose from with varying degrees of involvement required from the homeowner:

Increasingly popular and probably requiring the least input from the property owner in terms of project management are the all-inclusive package deals offered by many specialist building firms.

A great option for the competent DIYer is to have a shell only conversion. This is pretty much what it says on the tin with the builder doing all the structural work and completing the internal walls. This ‘shell’ is then left for the property owner to finish off.

Use an architect as the project manager and entrust everything to him or her. This is pretty much a hands-off role for the homeowner whose input is pretty much limited to coming up with the initial design concept that the architect turns into the final plans.

The final choice, and still a very common one, is for the property owner to directly employ designers and specialist tradesmen. This is very much a full-on role and means the homeowner is project managing the whole design and build process.

So, when it comes to managing a loft conversion, the first two options above are pretty much restricted to keeping a wary eye on builders and planners and making sure the work that is completed is done on time and to budget.

Though, having said that, the biggest single decision here is in choosing your builder. Get that decision right and you are most of the way there in passing your project management exam.

As already mentioned, using an architect is probably the easiest route in terms of managing a loft conversion and, if you can afford it, certainly something you should consider.

However, in terms of the fourth choice above, choosing your own tradesmen and micro-managing your project there are lots of decisions to make and you, as the property owner, will be performing a hands-on role throughout the whole process.

You could of course contract out the project management role but, if taking this on yourself, you will need to put aside at least eight weeks and as much as twelve weeks to see the job through to its completion.

So, what does project managing your loft conversion involve?

Your main role here will be coordinating the different tradesmen, ensuring that the right materials are delivered at the right time and that each contractor completes their work without delays. This is a lot harder than it sounds and needs a lot of organising.

A big part of ensuring the project is a success is in choosing the right tradesmen. Perhaps the best advice here is to make sure you only use specialists.

For example, plumbing work should be entrusted to a specialist plumbing company and not parcelled out to an electrician who says he is ‘handy with a monkey wrench.

Putting the right team in place is very important but here are a few other things to consider:

Make sure that each tradesmen knows exactly what is required of them. It is down to you, the project manager, to be very specific in what each tradesman is expected to do and that they complete their work.

Ensure that the materials each tradesmen needs are delivered at least the day before they are due to start work. Failure to do this will result in tradesmen standing around waiting for materials which will be hugely expensive.

As always, check out the references of all tradesmen and ensure they can actually do the job you have contracted them for. Don’t be tempted to employ a friend of a friend just because he is cheap.

Something that is often forgotten is to make each tradesman responsible for clearing and tidying after themselves and for disposing of all their rubbish. Failure to this can very quickly result in an untidy and dangerous site.

Don’t pay in full in advance. When managing a loft conversion agree a schedule of payments with your builders and contractors and stick to them.

Don’t pay extra and don’t make the final payment until you are absolutely certain that the work has been completed to the agreed specification. But this is a two-way street. Make sure you make your payments on time or the whole project could grind to a halt.

Why build a loft conversion?

Need to sell the project to your partner? Here are some compelling reasons to build a loft conversion and here we look at the top five reasons why home owners in the UK convert the loft.

Increased living space

The first and the most common reason to convert the loft is to increase the amount of living space in the house. So, it really isn’t surprising that couples with growing families are the people most likely to build an attic conversion.

In the past a growing family would simply move to a larger home but in today’s volatile housing market it isn’t that easy. Selling the current property is often difficult and the actual cost of moving to a larger property can be hugely expensive.

So, converting the loft is usually easier than upping sticks and buying a larger home.

Another side to this is that often of course we are settled in our home and want to remain there forever – which obviously poses a problem when that property becomes too small to cope when the size of the family increases. But a good loft conversion could add up to two bedrooms or living rooms plus an en-suite bathroom making a small house into one suitable for most families.

Add value to your home

There have been many studies and reports over the years released by banks, estate agents and property firms and they all agree on one thing. Building a loft conversion is the best and quickest way to add value to your home.

Conservatories, kitchens and new windows are all popular home improvement projects but only a loft conversion will add significant value to the property.

In this article we explain that by converting your loft you could add 15% to the value of your home.


Converting the loft for storage is very easy and quick and is a perfect way to add plenty of storage space to the family home. Building regulations approval is not necessary if you are going to convert the loft for storage and just a few hundred pounds will be needed for materials and labour.

Give the kids their freedom

One of the best reasons to build a loft conversion that I can think of is to create a playroom for younger children or an ultra-cool chill out room for teenagers. As long as you remember to soundproof the thing you are sorted!

My daughter absolutely loved her chill out room and it was big enough not only to include all the game consoles, computers and stereo equipment that teenagers need but could also accommodate a homework study area.

Bin the commute

More and more of us are working from home or starting a home-based business. Converting the loft into a home office is a great idea and, from the feedback I have received, it is one of the most popular of all loft conversion ideas for UK homeowners.

By creating an office in the roof, you are effectively separating your business from your home life yet saving a fortune on commuting and the costs of running a separate office.

More reasons to convert your loft

I’m sure you can think of plenty but adding a new large master bedroom, double bedrooms for the kids or a huge bathroom are all great reasons to build a loft conversion and to increase the space in your home.

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