Can I build a roof terrace without planning permission? (2025)

I am in the process of buying a top floor flat. It will be my first home after almost a decade of renting and saving for a deposit.

Although I'm happy with the flat, the one downside is that it doesn't have any outside space.

The seller mentioned the roof above is flat and perhaps in the future I could build a roof terrace up there to solve this problem. They said a neighbour a few doors down has done exactly that so there is precedent.

However, both my solicitor and my surveyor have said that it is very unlikely I will ever be given planning permission, given that I will own a share of the freehold and there are three other flats owned by co-freeholders in the building.

I would need all their permissions to get the roof space demised to me. Apparently that is unlikely, as they may feel like they are losing control of their own roof space by letting me proceed.

I was wondering if you have any advice on how I might go about persuading the fellow freeholders to agree? I'd be willing to offer them a financial incentive, within reason.

Ed Magnus of This is Money replies:There is always a risk when buying a property you intend to make alterations to -particularly when it is a flat within a shared building.

While it's good to think up ways you could improve the property in the future, you should always be prepared for the worst.

If having a future roof terrace will be critical to your future enjoyment of the property, then you may want to re-consider the purchase.

You would have to get planning permission from the council, as well as adhering to building regulations and paying for the alterations themselves, which could be costly.

But most importantly - as you rightly mention - you'll need the permission of your co-freeholders to make the changes.

This is because the building is ina share of freehold arrangement with each flat owner owning a share in the freehold.

Share of freehold is often deemedpreferable to leasehold, but in situations like this it can sometimes be more problematic.

This is because rather than needingpermission from one person or company, who owns the freehold of the entire building, you have to deal with a number of co-freeholders in the form of your neighbours.

People can get protective and territorial when it comes to their home, and some may not even be receptive to any financial incentives you throw their way.

You'll need to get all co-freeholders on side. They are the ones who'll decide whether they're willing to alter the lease for your flat to include the flat roof above, so that you can make the terrace.

For expert advice we spoke to Robert Habbitts, a residential conveyancer at law firm Parfitt Cresswell,Olivia Egdell-Page a partner and head of the property department at Joseph A Jones & Co solicitors, andJeremy Leaf, north London estate agent and a former residential chairman of the Royal Institution of Chartered Surveyors.

How easy will this be to do?

Olivia Egdell-Page replies: This predicament is something that I have dealt with in my own practice. You are not alone in your desire to create a roof terrace to enhance your living space.

With leasehold properties, the individual leases will determine the extent of the building each leaseholder owns.

The lease will detail whether you own the roof as well as the top-floor flat, or only the flat itself and no space above.

Either way, I'd expect that there will not be a provision in the lease to permit your conversion or proposed use of the roof area as a garden.

As your solicitor has rightly advised, you would need the agreement from all co-freeholders and may also need to vary the lease of the property so as to include the roof area and to allow you to use it as you intend.

It is likely that you would also be expected to cover your legal costs and those of the co-freeholders in the preparation of the required documents, as well as seeking consent from your mortgage lender.

Jeremy Leaf adds:Use of the roof as proposed is unlikely to be straightforward - even though the buyer will have a share of the freehold so is gaining a greater level of control than is sometimes possible in a larger development where the freehold is owned separately.

Although there is precedent with a neighbour doing similar, one has to wonder why the seller hasn't taken these steps themselves.

If it is possible to add a roof terrace it will not only add to the value, but help with the saleability of this type of property.

There may well be issues in the lease or management agreement, as well as structural issues, which make creation of the roof space uneconomical or impractical.

How could they get the co-freeholders to agree?

Robert Habbitts replies:You've mentioned that you're willing to pay them for the 'loss,' but there is also concern about them losing control of the roof.

It could be the case that the payment you offer would be enough to compensate the freeholders.

If not, you could offer to take on the responsibility of maintaining the whole roof and keeping it in good repair and condition as part of your amended lease.

This could be a useful bargaining chip as, in essence, you will be taking away the freeholders' duty to maintain the roof – which can be costly.

Seeking professional legal advice can ensure that all legal aspects are thoroughly understood and properly addressed.

Jeremy Leaf adds: You could also agree not to create a disturbance when using the space.

However, you may well need to pay the others for these rights, and the costs versus the benefits you receive may prove to be a delicate balance.

Do they need all co-freeholders on side to get the terrace approved?

Robert Habbitts replies:Technically the majority could agree. Given there are four flats in total, the top floor owner only needs two others to agree.

If there were three flats in the building, the owner of the top floor one would have to recuse themselves from the vote since they are the one asking.

It would therefore have to be the other two owners who agree as there is no majority of just one.

What else should they consider?

Olivia Egdell-Page replies:A separate issue to consider is the fact that you will need to apply for both planning permission, and building regulations consent, to convert the roof as you intend.

The planning application would consider the impact of the works on the locality, and so the fact another property has done the same thing may be in your favour.

Building regulations ensure the safety of the works, as it may be necessary for the roof structure to be reinforced in order to allow you to access the same and to walk around as you would presumably wish to.

Perhaps it would be worth a conversation with your local planning department to ascertain how likely it is that permission would be granted and the practicalities of converting the space, before approaching your co-freeholders to discuss the legal implications.

Jeremy Leaf adds: There could also be planning considerations to take into account and you will need to obtain any necessary consents.

You will need to consider safety concerns and may need to create a staircase in the flat as well as a skylight.

If this all means losing a lot of space in order to get access to the roof, leaving you with a tiny room, you might wonder whether the whole exercise is worth it.