Building a semi-detached house in phases - is that possible?

Hello everyone,

we have a plot of land in sight for building a semi-detached house. The owner of the neighboring plot is selling the 2nd half and wants to build a semi-detached house together. The problem is that he might not build his half immediately, but only after 2-3 years.
Is it then possible that we first build only our half on our plot, and the neighbor adds his semi-detached house only after a few years? What disadvantages are there for us technically apart from additional construction costs and renewed dirt from the construction site in a few years?
In particular, how will the party wall between the two houses be handled (insulation, soundproofing, etc.)?
And will something like this also be allowed by the [community]?
Does anyone have experience with something like this?

Thank you very much for your tips!
Best regards
Nils

The search function, no matter how bad it is, will provide you with quite a few very interesting results on this topic. The forum memory might even link them here since he knows them all by heart :p

Mandatory "have you already seen goalkeeper’s thread?" (This one: )

I don’t quite understand it yet. The second half of the semi-detached house is then on the neighboring plot, right? (I don’t quite get the whole selling stuff here, sounds a bit confusing)

Anyway, I think the answer is initially "yes, you can also just build one half first." You do lose some synergy effects. If you build at the same time with the same company, you save a bit because they can do most things in one go. That just doesn’t happen then. (How much of a "discount" the companies really give here, I don’t know) Otherwise, it definitely helps if the ideas are not too far apart. In goalkeeper’s thread, it was like this: they built without a basement, but the neighbor building later (in this case a mid-terrace house) absolutely wanted one. That’s a bit problematic (but also partly due to other ideas the neighbor had :D). But even there, after a long back and forth, a solution seems to have been found.

Otherwise, after moving in, you’ll still have the neighbor’s construction site and the related inconveniences right in front of you (noise, dust, possibly also scaffolding or blocked paths). It doesn’t have to be super bad, but it’s something you should maybe be aware of beforehand.

Planning is key. Ideally, you plan the two semi-detached houses simultaneously, with the same architect and taking into account the delayed development due to the 2nd side. This way, "construction sites" (literally!) can be mitigated. My own semi-detached house was extended. Everything works.

So... since I was kindly mentioned here by , I can tell you a few things about it, as we are currently in such a situation: If both of you want to build with a basement, then a common basement depth would have to be found. That makes the extension much easier later. If your house temporarily stands alone, you have to build against the neighbor as if it stayed alone - meaning: 17.5 cm KS with insulation like we have, or alternatively a 25 cm brick that also addresses the issue of sound and thermal insulation, since you never know if the neighbor’s house will start directly at the same point on the street as yours, or if it will also be just as high and long. Otherwise, parts of your facade will be exposed to the neighbor. Otherwise, we have now had almost six months of shell construction from the neighbor behind us, and one has to say it has really annoyed us: stone saw, hammering due to formwork, mobile crane in front of the door, concrete pump, etc. – and right next to the house wall. Otherwise, building alone usually goes smoothly: in our various building areas there are enough grandchild plots whose neighbors built decades ago and have stood alone since then. From a construction technical perspective, later builders can easily build their house – sometimes with more, sometimes with less effort.

Dear forum members,
many thanks for your answers!

I don’t quite understand it yet. The second half of the semi-detached house is then on the neighboring property, right? (I don’t really understand the sales stuff here, sounds a bit confusing)

The sale is quite simple: one originally large plot was already divided 1:1, one half is being sold normally, the other remains with the seller. The seller then wants to build his half as one half of a semi-detached house, but only later as a capital investment to rent out. We, however, would build immediately.

The key points are:
- we will definitely build a solid house, the seller so far wanted to build his half as a prefab house
- both of us want to build with a basement

The construction company sees no problem with this, our half will therefore be insulated and roughly plastered as weather protection.
One more question: the company builds solidly with Liapor, sand-lime brick with ETICS would also be possible. It will generally be an energy-saving ordinance house with air-water heat pump and central controlled residential ventilation with heat recovery. Personally, I tend towards sand-lime for soundproofing reasons. Is the difference then critical for a semi-detached house?