New single-family house in southern Germany

Well, there are also small model houses and simple ones. That's not the point. You don't have to choose your house there.

Above all, don't take model houses at face value and don't forget that they were by no means all built by the company selling their products there. The main purpose of model houses is to create an atmosphere in which prospective homeowners are first focused on their building dream and second believe they are acting rationally. Model houses do the same job for an investment as Christmas markets do for commerce.

Because of the soil survey, I called and also received it. Now I am just a bit uncertain about what exactly it means. My feeling as a layman and what I could quickly google together tells me that it probably will not come out on the cheap side.

According to the results of the geotechnical investigation, the construction of buildings with or without basements is possible. [...] Depending on the requirements of the planned buildings (loads to be borne, foundation level) or when encountering soft to stiff soils or loose compactness at the foundation level, additional soil improvement measures (e.g., the installation of a geogrid-reinforced soil cushion) may be necessary.

For buildings with a basement, one must expect temporarily accumulating groundwater layers. The building waterproofing must be carried out accordingly. Groundwater encountered during construction is likely to be well manageable with open water discharge.

What I understand:
- Basement would require a watertight shell due to temporarily accumulating water
- Rather soft soil, with low driving resistance values at samples 4 and 5 down to the bottom

Unfortunately, it is not clear from this – probably because it’s obvious to the expert – what measures are necessary. Is soil replacement required and how much? Can anything be done by simple recompaction?

So, a little update. The planning and discovery phase is progressing. I took another look at the soil survey and it doesn't seem as bad as feared. The clay layer relevant to us is at least rated with medium load-bearing capacity (whatever that specifically means). I also asked an acquaintance who works as a construction manager, and he didn't think the soil survey was that bad either. So the slab foundation does seem reasonable, although sometimes I still wonder whether the basement might be possible after all. On the other hand, arsenic was reportedly found in soil samples. It’s not entirely clear yet whether it affects the entire construction area, but if our plot is affected, the basement will become significantly more expensive and at some point the economic viability will ultimately collapse.

Accordingly, I played around a bit this weekend and tried out garden house and garage variants. The current favorite is the 3*6 garden house and a 6m garage with an attached carport, so the garage on the boundary, the carport next to it towards the center of the plot. That should look noticeably more open than a double garage, while my car would not only have a roof but also walls. This variant would just about comply with the allowed 9m boundary development to one neighbor as well as the total 15m limit ;)
I might then place the cistern roughly in the center between the house, garage, and garden house near the boundary.

There are also some updates regarding the construction partner. The regional general contractor’s planner sent a preliminary draft that avoids the space problem on the ground floor by adding an extension for the technical room. With the attached carport, it looks quite nice, but of course a bit sprawling. Still, I don’t think the idea is bad and a first wish-list meeting is in progress.
Today was also the second appointment at Schwörerhaus. In my preparation, I quite precisely identified some weaknesses in the construction description. If we build with Schwörerhaus, a fair amount of money will certainly still need to be spent until everything fits. Overall, however, it is certainly within budget.
What bothered me a bit was that right at the end of the conversation the price increase for next year was announced (and not at the earlier opportunities when I said I didn’t want to make a decision about the construction partner direction before January). Of course, there is the “option” to still quickly secure the old price now, but actually I don’t feel like signing anything quickly now and with more than a year’s waiting time, I’m also skeptical whether a 21-month price guarantee will even be enough. Our plot is still being developed and it will certainly take a few more months before the surveyor can even come. Actually, I have all the time in the world to decide on a partner.

Another update. Things are really busy again before Christmas. Yesterday was the second appointment at Weberhaus, today another one at Town & Country, and on Friday a local general contractor.

We really like a Weberhaus, the salesperson also diligently notes what we say and has a good memory of the first conversation. He also had a pretty good idea of how to move the staircase cost-neutral out of the dirt area. Basically, I would be tempted to buy the house if it weren't so expensive. Although the basement is now out, we are stretching the budget to the limit there, with a few extras like blinds in the study, air-water heat pump, underfloor heating and photovoltaic upgrade to 9.7kWp, we are at almost €3000 per sqm including painting and flooring (without kitchen, with base plate). That's really only within budget with subsidies, and not much buffer remains. I'm not quite comfortable with that, for flooring it's probably definitely self-contracting and for painting actually do-it-yourself. If the house price was about €30K lower, I think it would work.

The breakdown of incidental building costs with a total sum of €58K was quite high but seems initially quite realistic. Landscaping, carport, and garden house were also included in the calculation. I find that quite fair. Not so nice is that the possible subsidies were deducted right away and partly because of BAFA subsidies, there was a suggestion to decide soon.

The visit to Town & Country was kind of a contrast. With upgrades for the 42cm block for KfW55 without ETICS, underfloor heating, air-water heat pump, we are about €100K lower in the total sum, but still without flooring, painting, and photovoltaics. There will certainly be some catch-up costs, but overall it would be much more down-to-earth and also well within our budget so that moderate catch-up costs shouldn't be a problem. Since with Town & Country we had initially planned a basement that is now dropped due to probable soil contamination and corresponding disposal costs, a new floor plan was needed. Bodensee 129 fits well in terms of size, allows an east entrance without compromises, and does not appear too massive on the lot due to the somewhat narrower shape. The east-west roof would also be quite good for increasing the self-consumption of the photovoltaics and upgrading the battery later when it really makes sense. Over the next few days, I will have to find out where savings are made and whether that bothers us.

On Friday, there is still an appointment with a local independent general contractor. Let's see what comes out of that.

And another update right away. Today there was an appointment with the local main contractor. Down-to-earth fits quite well here too, the boss definitely still has worker hands. The basic equipment seems quite decent and the prices that were roughly mentioned also seem fairly moderate. In any case, I didn’t get the feeling that he is eager to sell every possible extra. However, he is still quite convinced that the BAFA subsidy will be extended and I can only limitedly understand the preference for decentralized ventilation. But well, in the end we decide what goes into the plan. The concept there would be KFW 55 solid construction with a brine-water heat pump, technical room in the extension. Although the floor plan is probably initially secondary because I didn’t get the impression that money is earned through deviations from the standard and we have been working directly with the building planner from the beginning anyway. Let’s see what comes out in the first offer in the end. I think over the holidays we can then narrow down the topic of building partners to a maximum of 2

and I can only somewhat understand the preference for decentralized ventilation.

I touched on this topic among other places here: and a preference of the general contractor for the decentralized solution usually stems from the then lower complexity of the system (not least for the ducts, which run through several components). Where does your understanding end?