Semi-detached house in Hamburg with general contractor on own land, two + full attic floors, no basement

Earlier I overlooked one point ...

Total house floor area approx. 165m². There has already been a preliminary building inquiry about it.

... and I missed another:

Each half of the house can be divided in the future without much effort into an accessible part (basement) and an apartment (upper floor + attic).

Reporting on the decision of the preliminary building inquiry would be enlightening. Move the nonsense about divisibility to the trash. This is a highly potent killer criterion that can destroy many plans and drastically increase the costs of all others, so that the destruction would have been the lesser evil. Changing the object in a serious case is the vastly cheaper solution.

Edith was too late to add this:

The kfw only grants funds within the framework of the budget funds provided by the federal government (voluntary benefits). In case no one has noticed yet, there is still no approved federal budget, meaning the kfw is still drawing from last year's federal funds. When those are all used up, nobody knows what will happen then. Will new funds be provided for this fiscal year, will the program be discontinued/restarted? That will really put you in a tough spot...

I personally don’t understand why one can’t provide information like, for example, 20x40 (meters), nor post a handwritten sketch of the property showing orientation, dimensions, streets, as well as the neighborhood.

Details about location, property, requested companies only later, so that it remains anonymous for now.)

Well, Hamburg, possibly Schnelsen or something similar (basically doesn’t matter), nobody wants to know that anyway.
Also, the requested companies are not of interest as long as you deal with them yourselves.

Or where do we think wrongly?

The most important aspect is that a) you can hardly build living space for less than 3000€/sqm anymore. And if expensive soundproof windows are required on top of that, then definitely not.
For 400,000€ you will not get 165 sqm built.
The second big mistake is the thought that b) you can simply divide a house on a relatively small plot into two adequate apartments.
How do you imagine living comfortably on 65 sqm minus technical room minus staircase?
That leaves you with about 53 sqm with a tiny shower-toilet, which is hardly usable. Plus an 8 sqm small office, which is supposed to serve as a bedroom?! That is then also not barrier-free just because it is on the ground floor.
Upstairs then a family bathroom, but no free space. Also no adequate parking space for two residential units.
Such thoughts are .so. secondary because they stand in the way of planning a simple and functional residential building.

We were advised that a concrete ceiling between the upper floor and attic would be sensible for full value.

Who advises that? That is nonsense! Why should concrete be better when it concerns your own house?
Then all wooden and prefabricated houses wouldn’t be full value..!?!
I don’t understand this repetition of the word anyway. The opposite of full value is inferior.
What comes to my mind is that your divided residential units are rather inferior because they are not comfortable and adequately livable.

But now, let’s get to the point: show the design!

That is helpful! Please keep it up.

... and I overlooked another one:
>> Each half of the house can be separated in the future without much effort into an accessible part (basement) and an apartment (upper floor + attic). <<
[...]
Throw the nonsense about separability into the trash. This is a highly potent killer criterion that can ruin many plans and make all others so much more expensive that breaking it up would have been the lesser evil. A change of ownership in an emergency is by far the cheaper solution.

That alone already requires a planning concept that you can’t just pull out of your pocket.

--> Ok, it has been thrown into the trash. We can "easily" part ways with that.

kfw 300, do you know the conditions? It’s like program 297. So kfw 40+. And beyond that, yes, CO2 balance and all that. To speak with the words of a colleague, it won’t be so easy with solid construction. Especially not with concrete ceilings and clinker...

I am not really familiar here. I’ve done some research but cannot assess what the structural and cost differences are between kfw55 vs kfw40 vs kfw40+ (vs kfw40+QNG, which we definitely don’t want). We were told sums of around 10-15k€ for the energy consultant, but presumably additional costs would also come in construction and materials. We don’t necessarily need that. But I thought the regulations in Hamburg were not so far from kfw40(+), probably I was quite mistaken.
If that could be "thrown into the trash" as easily as the other, one matter would be settled. BUT ...

That raises the question of how the financing is to be managed without funding programs (or maybe with ifb from Hamburg?, I don’t know the conditions...). If I’m not overlooking anything, higher overall interest and limits on duration and rate would put the cut-off below 40k€. Where/how should we proceed here? What would be your advice? We will certainly bother a financing advisor about this again, but it surely wouldn’t be wrong to have a few ideas first.

It is very sensible that you understand a semi-detached house as a whole. You only need a shared general contractor at the shell construction stage; the finishing work can be awarded differently by the neighbors.

Both parties have a very good relationship, have a lot in common and would like to support each other, so we want to try to decide as many framework conditions as possible together (although the details and especially the decisions about what is done as DIY will differ — but neither party will do entire construction phases on their own).

Your, , advice was even to select companies independently (and possibly separately) after the shell construction. I think we would rather prefer some organizational simplicity here if it is financially possible. But maybe that conflicts with the other goals?

I would recommend asking another general contractor (two masons and two wood builders), I usually take five or six in total. In Hamburg, you should definitely also find inspiration in house concepts from developer offers (the nationwide ones are mostly II+D with about 140/145 sqm).

Where does the advice for the wood builder come from? We have so far only considered masonry and solid construction. What have we overlooked?

By the way, a knee wall does not help with standing height, that would be a dormer (which however often would also break the full-storey line).

OK, did you understand it too? Your exact case is on page 7. You "plan" with a 3m boundary distance. In one case 2.80 fits, in the other 3.60 doesn’t fit, assuming it really is only 3m to the ridge "H2." That limits your plan quite significantly.

It was meant as dormer, sorry. We don’t really have problems with the full-storey line or boundary distance because it is about the lateral clearance area. Of course, there are details to clarify, but I don’t see problems there. But I may also have overlooked something (which is not unlikely, currently I seem to overlook everything). I might open another thread in the coming days in which I’ll post drawings and list a few questions about prioritizing roof pitch, story height, etc.

Taking house concepts from developer offers as inspiration (the nationwide ones are mostly II+D with about 140/145 sqm)

The semi-detached houses with II+D that I quickly found in a few other appearances all have a studio variant upstairs as well, so that concrete ceiling + dormer would probably mean significant redesign and extra cost. Right?

Apart from the wishes, the specifications are so incredibly individual, that’s something for a planner.

One more time here (I think I understand better now where this advice comes from): So visit an architectural office and have a plan made? But that certainly costs money. If then I build with another general contractor, that money might be (partly) gone. Or should we first look for a few more general contractors, modify their catalog houses and have offers made? And only then consider whether to go to an architectural office? What would be the advice here — and what does the advice depend on?

Thanks in any case!

So, visit an architectural office and have a plan made? But that certainly costs money. If I then build with another general contractor, the money is possibly (partly) gone

1. The money is not gone. Someone else just has it. 2. Every planning costs money. With an architect you see the invoice; if the GC plans, it is included in the total costs. 3. With a plan from the architect you can a) build solidly or b) as a timber frame and both 1. with GC or 2. with individual trades

1. The money is not gone. It’s just with someone else.
2. Every planning costs money. With an architect, you see the invoice; if the general contractor plans, it is included in the overall costs.
3. With planning from an architect, you can a) build massively or b) as a timber frame construction, and both 1. with a general contractor or 2. with individual trades.

Well, the money is gone with me. And then with the architect. But maybe a general contractor who works according to his own method would prefer to do his own (re)planning, which will then cost me money again, so that I partly pay twice and am stuck with the additional costs. Or where am I thinking wrong?

__

The second big mistake is thinking that b) you can simply divide a house on a relatively small plot into two adequate apartments.
How do you imagine living on one level on 65 sqm minus utility room minus staircase?
You then have about 53 sqm with a tiny shower toilet, which is hardly usable. Plus an 8 sqm small office that is supposed to serve as a bedroom?! That is then not barrier-free just because it is on the ground floor.
Upstairs, there is a family bathroom but no free space. Also, no adequate parking space for two housing units.
Such thoughts are .so. secondary because they stand in the way of planning a simple and functional residential house.

See just now (we wrote at the same time). It’s already moved to the trash bin. That could simplify the entire thread here.

The most important aspect is that a) you can hardly build living space for under €3000/sqm anymore. If expensive soundproof windows are needed, then definitely not.
So for €400,000 you won’t get 165 sqm built.

On the one hand: No idea what actual building requirements are linked to the aircraft noise. Triple glazing?

On the other hand: We don’t need 165 sqm anyway.
(a) I probably expressed myself unclearly:

House footprint total approx. 165 sqm

What was meant: 165 sqm of lawn on the plot will be converted into 165 sqm of concrete slab. Each half of the house therefore has a ground floor area of 164 sqm / 2 = 82 sqm, so a living area of (let’s say) 0.7 x 82 sqm = 57.4 sqm. If I calculate GF + 1st floor + attic, I get 172.2 sqm of carpeted floor, which is of course not so much living space because of the attic. Maybe the 165 sqm even fits as a figure.

(b) We can definitely forego a few sqm, but a “full” attic (more on this below) would be nice and reasonable.

Maybe like this (all sqm values are just rough estimates):
Ground floor: living-dining area with kitchen (30 sqm), utility room (8 sqm), guest bathroom (one unit with shower) (5 sqm), rest (14 sqm) divided between hall and another room (guest/work).
1st floor: bathroom (10 sqm), all three children’s rooms (3 x 10 sqm), another room (guest/work, 10 sqm), rest hallway (7 sqm).
Attic: master bedroom, possibly office, one unit also a bathroom with shower.

The master bedroom may be small. But it would be nice to have this third level with independent rooms so that the parents are sensibly separated from the children. Maybe it doesn’t have to be a concrete ceiling for that, but if there should be walls and proper heating etc. upstairs, you’d have to think about it... The budget of course sets limits here. In which direction would further thinking make sense? Plan without attic? Plan attic to be expandable later, but wait (as long as parents live on 1st floor, no guest room)? Attic only as storage (what to forgo to have one more room downstairs)?

Who advises that? That’s nonsense! Why should concrete be better when it’s your own house?
Then all timber and prefab houses wouldn’t be fully valid either..!?
I don’t even understand this repetition of the word. The opposite of “fully valid” is “inferior.”

As described above: walls and proper connection to heating and ventilation in the attic. BUT: Please ask further, maybe something is buried here that we haven’t fully thought through yet.