Are construction costs transferable to small houses?

According to the consultant, the air-to-water heat pump is the quietest currently available in Europe. 32 decibels for the outdoor unit. I’m looking for the device description, I only found an old one with 52 dB. They are always decoupled (flexible pipe) at the company. Noise level inside comparable to a refrigerator. But I am trying to follow your advice to look at it elsewhere, I just need to find out how to find new development areas (-;

Topic funding: According to the consultant, it is different for new buildings than for renovation: there is this additional clause that allows the energy consultant of the house building company to start through my signature and apply for the funding (2-3 days). The contract is void if the funding is not approved. Free cancellation.

Costs signature construction contract: Costs only arise for me once I tell the architect: please start now. The house building company initially does nothing until the building application is approved. Until then I can, for example, check the soil condition, the usability of the foundations of the old barn, etc. If I realize that it becomes too expensive, I can withdraw free of charge. My concern was that I would have to pay an 8% penalty. Of course I have to pay the architect once he invests time.

For the funding application I only need to clarify exterior dimensions, windows, insulation, etc. Even the windows can still be reduced or moved at the end without the funding becoming void. To be clarified at the end of the construction.

Even if the price is not exactly low. That is also due to me: many large, partly expensive windows/terrace door, chimney connection, etc.

I can remove items at any time without penalty, even after signing.

(Maybe this information helps other builders in planning :)

On the topic of the right of withdrawal (for other readers) in case the funding does not work out:

According to FAQ KFW 3.11:
A right of withdrawal is not sufficient; it must be a "suspensive or resolutory condition," meaning that the contract does not become void voluntarily but automatically, making it clear that the efficiency level is only achieved with funding.

Since the price of the offer alone has increased by 20% since summer and especially because the delivery time after building approval is 18 months, I will still call a local architect on Monday to get his assessment of whether the construction project can be implemented within half the time for a comparable or significantly lower price, with local construction companies and craftsmen (rural area, economically weak region).

Of course, this is not a guarantee like the offer from the house provider (2 years fixed price) assures me. In addition, the 30-year shell construction warranty will be eliminated, and considerably more risk and effort arise; "factory quality" might possibly be lost. However, there is more opportunity to contribute personal effort and thus reduce the construction time. I have craftsmanship experience privately, also enjoy it, but I also have a full-time job (virtually self-employed).

It’s a bit crazy on such short notice, but hey, it’s about 32 years of cold monthly rents from the building alone (excluding additional construction costs). As with any "enterprise," risk and benefit must be balanced. We’ll see.

So, I think this is my last update for now:

- Self-award / architect I have excluded, as in my estimation not drastically cheaper/faster (than 6+18 months)

- I have checked the contract etc., I was still missing 1-2 rights of withdrawal. Right of cancellation, missing funding and financing were included (free of charge)
- however unclear whether missing building permit triggers penalty payment and the verbal assurance that free withdrawal until building permit regardless of reason "because the provider does nothing during that time" is of course missing (-; but that would also be very generous. I do find the assurances already not bad.

- Total cost estimate (as a layman, after much research):
200K offer
minus 30K funding
plus 40 to 130K incidental construction costs
where here a small part is for outdoor facilities and furnishings (kitchen). But really a small part :)

I fear that with the total price and the price range I cannot spontaneously sign a contract.

(Probably was foreseeable ...)

But I took 5 vacation days + weekend, 8-12 hours daily to read up on everything. Until I made the detailed total cost estimate (incidental construction costs with current values from the net) I was actually still very willing to sign, since of course a long-cherished dream.

For future readers, I must fairly say that I did not plan with the minimal requirements. Last year, after reading here in the forum, I was often demotivated because at first I thought "I don't want much" but mainly found examples with advanced requirements. But when building is so expensive, the expectations naturally increase that you get something you also like.

As of today, there are also flying spaces with 50 sqm from 155 T (here including air-water heat pump, underfloor heating).

However, this is the basic equipment. That means individual small windows. It is important to me to have a large window front, especially when bedridden in old age, so that you don't just look at a wall (personal experience in the family).

That means without such demands, one could build a KFW 55 EE 50 sqm house with 155 T plus 30-40 T ancillary construction costs, with point or pile foundations if the soil permits.

Currently, however, there are uncertainties like barn demolition, soil condition, slight slope, etc. included in the ancillary construction cost planning. And also the advanced equipment (4 2*2 meter windows or doors on the south side, fireplace connection, possibly skylights). Therefore 200 T + 40-100 T ancillary construction costs, and for outdoor facilities and interior fittings I have roughly 30 T (own work, used furniture, minimal kitchen etc.) Very roughly calculated, since in the countryside with own forest, so the garden will mainly remain a meadow, fence is not necessary, etc (-;

I just thought I should write that fairly.

My amateur ancillary construction cost estimate looks like this in detail:

Architect: 6.5 T
Surveying: 2.5 T
Construction site setup: 1.0 T (WC, electricity, water)
Construction road and crane parking space: 1.3-3.5 T (on the property)
Soil survey: 0.8-1.2 T
Police escort: 1.0 T
Structural analysis/carrying structure/foundation: 0.0 T (included in the offer)
Foundation dimensioning: 0.0 T (presumably included in earthworks/architect)
Construction manager, own tenders: 1.0-6.0 T (depending on whether architect involved)
Building inspector (deficiency determination): 0.8-4.0 T
Structural engineer: 1.0 T
Foundation earthing: ?
Supply lines: 6.0-14.0 T (property boundary to connection box, slope, current development just assumption)
Road closure: 0.3 T
Insurance: 0.0-0.6 T (during construction)
Permit/authority fees: 0.3-1.0 T
Demolition work existing building: 2.0-10.0 T (possibly with foundation and disposal)
Medical costs: 3.0-5.0 T
Point or pile foundations: 5.0-7.0 T
Earthworks (area, removal, compaction): 10.0-30.0 (if a floor slab is required due to groundwater)
Tree felling: 0.0-2.0 T
Flat roof filling (gravel or greening): 0.3-3.0 T

This brings me to 43-100 T ancillary construction costs.

Buffer for simple outdoor facilities, with a lot of own work: 3.0-15.0 T
- House entrance, path, car parking space
- Entrance canopy
- Terrace with canopy
- Fence/privacy screen

Buffer for simple interior equipment, 5.0-15 T
- possibly upgrades (bathroom, facade, floor, walls, tiles, doors) although this should be low with S.Haus, according to experience reports
- kitchen, living room, dining room
- wood stove, washer-dryer

Bye Bye Stress Factor
So, the KFW 50 funding has finally expired, which put me slightly under pressure. I'm now directly requesting Kfw 40 from construction companies, it should be standard in a few years anyway...

Demolition of wooden barn on my own
I have meanwhile confirmed with the building authority that I am allowed to demolish the existing wooden barn (7*14 meters, one story with a gable roof) on my own as long as I "register" it for free, so the incidental construction costs for this are already waived, another good thing.

Preliminary building inquiry
However, the building authority advised me to still make a preliminary building inquiry since the building site is located in the outer area of the village, although within the village sign; this can be done without an architect and only costs 50-70€. I will do that in the next few days. I will immediately mention all "problematic" factors such as: one story, small footprint, flat roof, timber frame and wooden facade, all unusual for a northern Bavarian village. We'll see, it shouldn't fail because of the construction method, facade or roof shape, but maybe it will pass like this, there is no building plan, but it still has to fit into the surroundings...

Regional construction company
I was pointed to Übler Haus, they sell houses that are manufactured by our neighbors in the Czech Republic, so presumably good quality, and they even have some tiny houses in their model house park, I will check them out soon. Then they will certainly be more "enthusiastic" about my "mini house" project.

Retrospectively, 1.5 years later:
Financially, it would have been good if I had signed the contract with Schwörerhaus, especially because of the 37K "free" from the state ;-)
Nevertheless, I wouldn't do it differently today: If I want a prefabricated house that is delivered completely, I don't want an 18 (now 24) month delivery time. For me, it's more a matter of principle ("unmodern", I can't stand it, colloquially speaking).

Current status:
I put the project on hold and first moved to the region, into a modern apartment (I often have half a house to myself) to have a similar feeling as in the small house. I have lived there for 1 year (home office for 4-5 years) and I love being able to go to my grandparents' garden after work, where I also want to build.

Regarding the house building project:
In a few days, I have a phone call with HomeOne (Cabin One/Bay/Suite), I like the Cabin Suite style. Let's see what the delivery times are there. That would be the direct knockout criterion. Then it would be around 300K including additional construction costs/demolition of barn foundation for 65 sqm. I would have paid it off in 10 years, I live quite frugally.

Fingers crossed regarding the delivery time (and of course standard conditions like paying most of the amount only upon handover, etc.).
If they also have delivery times > 12 months, I would probably have to slowly turn to conventional companies after all.
I shy away from that because recently, despite cost estimates, my family regularly had invoices from craftsmen in the mid four-digit range that were 2-3 times as expensive. That makes a house that has already been built in exactly the same way 100 times simply more appealing.