Consultation house type

Hello everyone,

we have the opportunity to buy a piece of land from a municipality and would not pay an excessive price.

We now have two offers, one for a solid house on a slab and one for a prefabricated house, also on a slab.

Both are priced equally, each fully turnkey. Therefore, it does not matter.
Only the offer from the solid house provider seems more transparent to us since simply a price range for floor coverings, etc. is listed and one cannot only choose from a showroom.

Now comes the actual question. Each provider, of course, disparages the other’s service, e.g., the prefabricated house provider says "only with us do you get a mold-free house, you can’t achieve that with solid construction."

Is that true or do you simply have to let a solid construction dry longer?

Since we are somewhat "mold-affected" (we have slight mold infestation in our current apartment, solid construction) that sounds tempting, especially since according to the consultant no ventilation is necessary in the prefabricated house because a ventilation system is integrated.
In my parents’ house (prefabricated house) there has been no mold even after 45 years.

The solid house would be built from 36cm Ytong blocks. The prefabricated house would have about 34cm exterior walls.

As far as I understand, Kfw55 is now mandatory and fulfilled by both.

Heating would be either gas with solar or an air-to-water heat pump in the solid house and an air heat pump in the prefabricated house.

What are your opinions on this?

If I have forgotten anything I will gladly add it later.

Regards

It is mandatory that the Energy Saving Ordinance 2016 is fulfilled. KFW 55 is not mandatory. Whether solid construction or timber frame construction is largely a matter of taste; each has its advantages, although timber frame construction is probably slightly more expensive than solid construction. I would consider a ventilation system very useful. Providers who disparage other providers are, in my opinion, not good advisors. One should highlight the strengths of their own company and, if applicable, the advantages over other companies, but not disparage others.

After the building moisture has dried out - except in cases of very rough botching - problems only occur due to incorrect use. A ventilation system helps tremendously here.

Am I mistaken, or does a prefabricated house also have screed? The only problem we had was after the screed was applied because of the 3-day ventilation ban after its installation - this could have easily been completely avoided with a slightly better sequence of work steps (drywall after plaster and screed).

Since then, we have had no mold problems - and the problems were not that dramatic anyway.

The consultant is completely unreliable.

In my parents' house (prefabricated house), there has been no mold even after 45 years.

45 years ago, houses were not as airtight as they are today. Therefore, there was natural ventilation. There are also plenty of solid buildings that are also 45 years old and also dry ;).

Plot. But is it correct that there is somewhat more moisture in the solid house than in the prefabricated house? There, moisture "only" comes from the screed.

KfW 55 is not mandatory. Does the solid house also have a ventilation system? If not, you should seriously consider it, unless you are home a lot and can ventilate frequently (not only because of moisture but also due to air quality—and thus quality of life).
Mold is not an issue, regardless of the house type, if properly ventilated.

Then think about the heating. Whether an air heat pump makes sense in a prefabricated house is debatable. It depends on your living location and the prevailing outdoor temperatures. After all, you first need to have warm air in the house to "feed" the heat pump. In cold weather, you might end up heating expensively with electricity.
An air heat pump has the advantage for the home builder that it is significantly cheaper than the solid builder's option (e.g., no underfloor heating!). Therefore, both houses might be roughly the same price but differ in performance :(.

I personally would build solid only but skip the nonsense with gas + solar. Rather a heat pump and, if applicable, photovoltaics. But that is my personal opinion.

A disadvantage of the prefabricated house can be that although it is built quickly, you might have to wait a year for delivery. The order books are full... Maybe you will already live in the solid house before the prefabricated house is even delivered.

Hello, to compare the two offers, you have to do much more than that:

Price-wise, both are the same, each completely turnkey. Therefore, it doesn't matter.

You only look at the price at the bottom right and the word "turnkey". However, that doesn't help you because turnkey is not explicitly defined. You have to compare the construction service descriptions exactly.

That the houses are not equipped the same can be seen in your two examples:

with the prefabricated house, no ventilation is necessary because a ventilation system is integrated

Heating in the solid house would be either gas with solar or air-to-water heat pump, and in the prefabricated house an air heat pump.

If you yourself do not have the knowledge and time (which I currently assume) to compare the two construction service descriptions, you should get external expert advice.

Many local carpentry companies also build complete wooden houses, which would be a third option. We decided on this because we like wood and the chosen company seemed the most honest to us (no sign-today-super special prices and annoying calls) and we have not regretted it so far.