uninsulated basement = wet basement?

Common (meaning for both semi-detached houses) reinforced concrete slab as a WU construction (white tank). Thermal insulation on the basement ceiling in the floor structure of the ground floor. Thermal insulation of the slab in the stairwell area.
Walls made of reinforced concrete, uninsulated or with flank insulation. The basements are not living spaces. Basements as WU construction.
Single-glazed basement windows.
Best regards
Ricardo

Nice if the plot fits - the basement doesn’t sound so great. Sound transmission with a shared slab would be the first no-go for me.
With an existing property, you also look at the house + plot - you have to do the same with the developer. And if the house is shoddy, the nice meadows won’t help you at all.

Hello Wastl, the basement does not sound so great according to the current planning, unfortunately. That is why I am considering whether it can be reasonably designed with certain changes. For example, with perimeter insulation of the basement walls.

The shared floor slab should cause little noise interference, according to my research. After all, the floors above are provided with a separation joint and consist of 17.5 cm thick masonry. I hope it is made of sand-lime brick, but that has not been confirmed to me yet. Such a construction is probably also considered good by the sand-lime brick industry and complies with the increased sound insulation according to Supplement 1 of DIN 4109 (i.e. at least 67dB attenuation). This is also achieved by the developer according to the building description.

Another consideration now is to inquire about a controlled residential ventilation system for the entire house including the basement, in addition to the perimeter insulation. In order to ensure air exchange and prevent moisture problems.

Hello Ricardo,

One developer with the better house offers a shoebox plot, the other, with the "worse" one a dream corner plot, almost twice as large. That also answers the question why we feel it's better.

No. A plot can never be so beautiful that I would buy incalculable additional construction issues – and these without necessity – along with it.

So far the BB is only preliminary, on two DIN-A4 pages. Marketing only starts at the beginning of next year. But talks are already underway to get some buffer until the end of the KfW-70 subsidy.
The BB should of course still be expanded and specified.

Strange approach?! We have a BB that is applied for all BV; of course extendable via additional agreements. What a logistical effort to write an individual BB for each BV.

Have you at least obtained information about the preferred provider? Considered involving external expertise in the housebuilding adventure?

Rhenish regards

Hello construction expert,

that is all true as well – the construction description is very rough, what is included is not really convincing. But the plot... actually outstanding (adjacent to a park on two sides, twice as large as that of the competitor, southwest orientation). But nothing has been decided yet.

The developer is a company that has been around for more than 100 years, with the city as a clear main shareholder. Many projects by this company have already been realized in Cologne. I have heard a lot of praise and of course also some flaws about this.
The general contractor (or general entrepreneur, I am unsure about that) has also already completed many large projects. For example, I work in one of their buildings.

We want to get a construction supervisor on board – yes. But with the current construction description, I do not want to assign anyone to review it yet, because there is simply too little information in it.

Now at least we appreciate the construction description and the intended executions of the competitor developer.

Best regards
Ricardo

Hello Ricardo,

The developer is a company that has been around for over 100 years, with the city as the clear majority shareholder. Many projects have already been realized by this company in Cologne. I have heard a lot of praise about this, and of course some flaws as well.
The general contractor (or -entrepreneur, I am not sure) has also completed many major projects. For example, I work in one of their buildings.

That doesn’t mean anything at first. Why? A few weeks ago I responded to a tender because the buyers simply wouldn’t leave me alone. It concerns 2 x 3 row house blocks, with the awarding of further 200 housing units tied to it. Of course, the gentlemen thought this bait would affect our offer price; wrong idea. Therefore, I hoped the matter was settled. Wrong again ... hope and wait ...

Anyway – when I read through the room book, I nearly lost my faith, it was put together so sparsely. If I now translate this to your scant information about the preferred provider, you can safely assume in my opinion that you will have to buy many extras at a high cost. Because clients of larger housing units primarily look at their return, not meaningful equipment.

If you internalize this, involve external experts and your budget fits the desired house: all good. Otherwise, you should keep your hands off the offer.

Just my 2 Coins

Rhenish regards

Especially when it is a renowned developer with a long tradition, they should write such construction descriptions professionally and in such detail that even expert reviewers are sufficiently and clearly informed. They should include detailed descriptions of the shell and interior construction / technical installations, including precise material descriptions and well-founded statements on soundproofing / thermal insulation / moisture protection, and if applicable, fire protection. As a potential builder, I would not want to be satisfied with rudimentary technical information, pretty pictures, and brochure texts.