Side return extension at same time as neighbours – pros and cons?

[tpmumtobe]

We are planning to do a side return kitchen extension (standard Victorian terrace) in the next couple of years, pending saving the rest of the money.

New neighbours moved in next door (on the return side) last month and have popped round to give us a heads up that they are about to put in planning for their own side return, work to start in the New Year.

We are not at a point to proceed with ours, but it’s occurred to us that there might be potential advantages to negotiate with them before they start their works.

For example, should we suggest they build the wall along the boundary? So that we can share it (pending a £ contribution) for our own extension in due course?

What about agreeing to a higher party wall? Would that potentially give us both more head space in our extensions long term (our house is set slightly higher than theirs)? Though obviously it would restrict light to our kitchen in the interim/if we didn't go ahead.

There would be obvious advantages to building both at the same time in terms of mess and disruption but we're just not at a point to proceed yet and don't want to rush our planning process. We just want to make sure we don't miss a trick in future proofing our options.

If anyone has done similar or has any advice or suggestions I'd be very grateful!

I'd ask for the name of their architect and see if you could have a chat with them initially. They'd be able to suggest if there's anything they'd do differently if they knew they were doing both at the same time.

It's worth discussing with them I think and potentially even going to planning at the same time, which is something two neighbours of mine did, although only one of them actually built the extension in the end. The planning consent will be valid for a couple of years, which sounds like it could be long enough for you.

The neighbours will at the very least need to have a party wall award with you, and are likely to want to build onto the boundary wall as that will give them more internal space. If they go first and you build your extension later, you would then need to pay them to use the same wall as the basis of your own extension.

You should take some advice though; you'll never be in a stronger position with your neighbours than when they need planning consent and a party wall agreement! Being collegiate with them now will stand you in good stead when you come to do your own work.

I would definitely approach the neighbour about this, with a view to maximising space and sharing costs. You are much more likely to not have objections raised about yours if you've talked to neighbours about it beforehand.

I'm currently buying a house which I plan to extend along the boundary, and would love it if the next door neighbour approached me about doing same. There is not a huge amount of space so it would be to both our benefit if we did it together.

I read an article about this recently while researching:
www.standard.co.uk/homesandproperty/interiors/enterprising-london-neighbours-team-up-to-extend-their-homes-saving-both-projects-thousands-a124921.html?amp

As I was browsing I also read this, which may interest you:
www.houzz.ie/magazine/architecture-inspiring-ideas-for-side-return-glazing-stsetivw-vs~51119749

Brilliant thanks very much everyone, really useful. We're going to meet with their architects and will get someone to advise us on their plans either way.

@Zinnia Do you know how paying for the wall works? Presumably we'd pay half but only once we were ready to build, not up front? You're totally right though, we'll never be in a stronger position to negotiate!

@Starseeking that's exactly what we're thinking, if we share the cost of the wall and give each other a bit more space that's a win all round. Thanks for the links, will have a look.

We would really love to be able to do it simultaneously (so much less disruption!) but building costs have shot up and we just don't have enough saved yet. At least we can watch what they do and learn from it when we eventually do ours!

On the planning consent my understanding is that as long as you've substantially started the work then the consent doesn't expire after two years. I'd think doing some work on the wall might count towards that - again, an architect can advise.

I would 100% put your planning in at the same time and consider using the same architect. We are a victorian terrace and some neighbours did theirs at the same time and had a shared party wall and both were allowed flat roofs.

Our immediate neighbours were happy to allow a shared party wall but were selling so no plans to extend. The council turned down our flat roof planning and we had to go pitched.

Could you afford the plans and shell of your extension yet OP? I think the opportunity to get the planning through and structure up at the same time as the neighbour is too good to miss. You could then either stop before the knock-through stage to minimise disruption whilst you save up the rest of the money, or carry on doing a bit each month as you can afford it.

As regards the wall, yes if you build against a wall a neighbour has built, you pay half the cost of building the wall. But only at the time you do your own building work.

I would agree with getting your own plans worked out at the same time. The main thing is to try to ensure they build theirs in a way that allows you to do what you want- in particular that their wall is on the boundary and goes high enough.

Ultimately however if they want to build within the boundary and/ or have a short side wall, there is not a lot you can do about it and will just need to make the best of it when you do your own extension.

But good to work out what you’d ideally want so at least you can ask them.

@Ecthelion

On the planning consent my understanding is that as long as you've substantially started the work then the consent doesn't expire after two years. I'd think doing some work on the wall might count towards that - again, an architect can advise.

In my borough you have 3 years to start building work once planning is approved (it used to be 5 years), though I couldn't find a limit on when the work has to be completed by. The time constraints may vary by borough, so that may be helpful OP.

I'd also look to see if there are parts of the shared wall that you may be able to finance now, so at least it's done before you get to the main build.

We'd be happy to crack on with planning in theory (and have the £ for that), but we don't want to rush it. When we first bought this place about 10 yrs ago we renovated on the cheap, in a rush, with a totally useless architect and we made so many mistakes! We've always said if we do any big work again we'll take our time to find the right architect and plan out all our options. We've spoken to a couple but not found one we want to commit to yet.

We also want to do a dormer loft extension at the same time so it's a lot of work to plan out. The neighbours are putting planning in next week so we'd be playing catch up.

You're all absolutely right though, if nothing else we need to focus on making sure they're ok with the wall being on the boundary and that they build it as high as possible, even if that does block light in the interim. Their property is stepped down from us too so a very tall wall for them is actually that bit shorter for us.

I'm off to check planning time constraints. Thanks very much all!

Note: some councils place restrictions on side return wall height, in order to prevent the neighbour’s (undeveloped) side return from becoming too dark. So in fact, if you flag up that you plan to do your own extension soon and have no objection to a high wall, this will help your neighbour get a higher wall through. (Assuming they want to). You don’t have to do this through your own PP application but talk to your neighbours and put in a supportive comment making this point clear on their application.

I'd definitely be considering applying for planning permission jointly. The architect's fees for both extensions as a single project should be lower, and your planning permission will not expire once you have made a substantial start on the building work. You could probably fulfil this by (e.g.) having the joint party wall built, which your neighbours would be needing now anyway, but check with an expert!

If you can possibly build the two extensions at the same time there ought to be significant cost savings: digging a second set of foundations when a digger is already on site takes little extra effort. Pouring concrete for two extensions once a concrete pump and readymix truck are there is no trouble, and so on and so forth!

Even if you were planning to fund the extension from savings and bringing forward the work means you have to increase your mortgage to fund it, at least do some sums to compare the cost of the interest and fees with the savings on the byild costs.

Hi, we built a side return with our neighbour and got joint planning permission

Pros:

• we built 4m tall party wall and have a beautiful mega high ceiling! Without joint permission I think the max height is something like 2.2m

Cons:

• The neighbor built first then we followed 1 year later. We then had to pay then market cost for the share of the wall. Had we built at the same time then we would have paid £3k less as we would have paid the exact build cost (the party wall surveyor can explain to you how this works)

Other than the party wall we did not save on build costs or architecture costs. We used the same builder who said the time and material cost is the same so they couldn't offer a discount. And their architect was a knob so we used our own.