Can a pair of semi-detached houses be built one at a time?

[nextplease]

Myself and my brother are seeking planning permission to self-build a pair of semi-detached houses on a piece of family land. Needless to say it would make sense to build them at the same time BUT my brother wants to build his semi-detached house straight away whereas I want to build my semi-detached house in years to come.

 

With this in mind my brother is considering building his semi-detached house before mine - how best can this be achieved?

 

At the point when one of the semi-detached houses is built will it be difficult to tie in the second semi-detached house at a later date?

 

I had two thoughts:

1. For minimal disruption I wondered whether a flying freehold could be created between the two semi-detached houses in order to minimise the party wall disturbance by trying to tie in the new semi-detached properties brickwork to the flying freehold as oppose to the party wall.

 

2. Alternatively I wondered whether a new party wall could be built touching what would be the gable end of semi-detached house 1 which would then eliminate the need to tie in the brickwork of the second semi to the first?

 

Does anyone know of pair of semi-detached properties being built one after the other and how was this achieved?

 

Does anyone have any thoughts or recommendations? 

 

Any advice would be greatly appreciated.

[Adsibob]

You would get economies of scale and efficiency if you worked together to build both at the same time. The cost of plumbing two houses is slightly less than 2 x the cost of plumbing one house. Same goes for most other work. If you are rendering the outside, you will get a much nicer front and rear elevation if the whole thing is rendered at the same time. If building with exposed brick and mortar, the mortar colour will come out more consistent across the two houses if mixed up and laid at the same time.

And also, if many of your features, such as windows, match you will get a much more attractive and cohesive looking outcome.

Is there no way he can slow down or you can hurry up?

Edited October 19, 2022 by Adsibob

[Mr Punter]

With a bit of thought I don't see any particular issues.  Make sure the correct agreements, rights, obligations and consents are in place.  Bear in mind that one party may dispose of their part and another take over.

[nextplease]

Thanks Adsibob, I really hadn't thought about any variation in appearance due to the difference in the timing of each semi-detached house those are really good considerations. Sadly I think we are set at moving at different speeds due to us each being at different stages in life.

[nextplease]

Thanks Mr Punter, I completely agree that we need to get the correct agreements and rights/consents in place especially when it comes to the party wall and access. Is it possible for my brother to consent to any party wall arrangements in advance (and if he sold up that this right would still remain for me to tie in my property)?

[Ferdinand]

Can anyone come up with an estimated extra costs that will apply?

 

Two of the obvious ones are:

 

• Legal paperwork costs, for which I reckon you will be looking at low 4 figures (punting - £1k to £3k).
• Reduced sellability and value of the first one built, for which the first person building may have a reasonable expectation to be compensated if the second person does not build within a reasonable period.

 

What exactly are the benefits of doing it this way?

 

My considered view is that it is probably a far better plan to build closely spaced detached houses, which will defuse a huge number of the complications.

 

I would say split it equally with perhaps an agreement how far you will be from the common boundary, and sharing what you can share (drains and driveway?), both get PP, you put in enough groundworks to lock yours in, and rent it to your brother for a peppercorn for a bigger garden until you want to implement your PP.

 

I can't see much upside, except perhaps in having one Planning Application that cannot be withdrawn, but that would mean that there may be issues about signing off the completion of the first house as the PP will not be completed for 10 or 20 years. Are there complications there about house 1 getting its self-build subsidies and tax breaks - which require completion (eg the VAT reclaim). Other know far more about this side of the paperwork than I do.

 

You need to examine this very very carefully and cost benefits, including potential impact on your filial relationship, or you may discover dragons later, and have a dispute.

 

My experience of this was that I bought a cottage off my gran, which with her house was potentially going to form access to a biggish building site behind. It came off 24 years later, but I was stuck with the same house for that period of time, and there were some brief but hellish family politics based around my ownership in the house I owned making my interest diverge from my sibling who owned the other half of the building site but lived 200 miles away. So things that mattered to me were just seen as an obstruction to making the maximum money.

 

Ferdinand

 

[Adsibob]

18 minutes ago, Ferdinand said:

closely spaced detached houses

not sure i agree with this. The semi detached has a number of advantages, such as cheaper to build and good insulation on party wall. The economies of scale should not be underestimated. Just some examples:

• Putting up scaffolding and roofing one house probably costs 60% of scaffolding and roofing for two houses.
• You will get better discounts if you are buying six toilets versus 3 toilets.
• If the houses are very similar in layout and just mirror images of each other, the project management and design stress is effectively halved as you get two for the price of one in terms of stress being the same, but getting two results for that stress rather than one. To put it a different way, if the OP could persuade his brother to manage the build of his house at the same time, the OP gets a stress free build, albeit brother may have a coronary.

[Ferdinand]

6 minutes ago, Adsibob said:

not sure i agree with this. The semi detached has a number of advantages, such as cheaper to build and good insulation on party wall. The economies of scale should not be underestimated. Just some examples:

• Putting up scaffolding and roofing one house probably costs 60% of scaffolding and roofing for two houses.
• You will get better discounts if you are buying six toilets versus 3 toilets.
• If the houses are very similar in layout and just mirror images of each other, the project management and design stress is effectively halved as you get two for the price of one in terms of stress being the same, but getting two results for that stress rather than one. To put it a different way, if the OP could persuade his brother to manage the build of his house at the same time, the OP gets a stress free build, albeit brother may have a coronary.

 

OP has stated that they will be built many years apart.

 

But yes - everything needs to be very carefully thought through.

[Dave Jones]

You would be mad to at least not get the footings poured at the same time.

[Conor]

The biggest issue I can see is BC signoff for the first house. The plans will show a party wall, which has a different specification to an external wall. Your brother will have to change the design of the wall to an external wall sepc - e.g a insulated and vented cavity wall. So extra cost. And when it comes to build your house against it, there may be other implications. Does a cavity wall meet the same requirements and a party wall? How do you tie the brick work (if applicable) together?

 

At the very minimum you'll be adding tens of thousands in extra costs by not doing at least the main structure at the same time. Biggest costs savings would be groundworks, floor slab, walls and roof.

 

Would you be able to do the slab, services, walls and roof of your half? Then do your fitout down the line.

[Adsibob]

14 minutes ago, Conor said:

The biggest issue I can see is BC signoff for the first house. The plans will show a party wall, which has a different specification to an external wall. Your brother will have to change the design of the wall to an external wall sepc - e.g a insulated and vented cavity wall. So extra cost. And when it comes to build your house against it, there may be other implications. Does a cavity wall meet the same requirements and a party wall? How do you tie the brick work (if applicable) together?

 

At the very minimum you'll be adding tens of thousands in extra costs by not doing at least the main structure at the same time. Biggest costs savings would be groundworks, floor slab, walls and roof.

 

Would you be able to do the slab, services, walls and roof of your half? Then do your fitout down the line.

In general I agree with this. Only thing I'd say is that an external cavity wall would provide better sound insulation than a typical party wall, so it might be a win-win to just build the party wall as a cavity wall, but instead of filling it with heat insulation, fill it with sound insulation, assuming that passes the regs. The only thing worse than a party wall that is sound permeable, is a party wall that is sound permeable with your relatives living on the other side.

 

I agree that you should try and build a watertight structure at least, even if it means doing things out of step with your life plans. My mum always says there are life plans and there's life. There is little relationship between the two other than life is what happens around your life plans. The other thing the OP, @nextplease could take into account is that building now will save money in the long run. At current inflation, what you spend now will be much cheaper than what you spend in the future. Regs will also become more demanding every few years. Of course you need to off set the inflationary savings against any borrowing costs, but if you are just building the foundations and the structure now, the fit out, which depending on spec can be the really pricy bit, can wait till you've got the cash.

[Temp]

We could see a few companies go bust over the next few years. Could end up with different roof tiles, windows, possibly even bricks. Even if they are still available the colour difference might be noticeable at the join.

 

Some if this you can design out, for example by not making them identical rectangular boxes so there isn't just one long front wall. But perhaps they have to match existing/neighbouring houses.