House construction with TuC and changes - Your opinion?

Hello building experts and construction friends, I have been reading along for a while and now I also need some tips. We would like to build with TuC here in Saxony, postal code area 02. The companies that build for TuC here have a good reputation and there is a lot of construction going on at the moment. Most people simply build a cheap little house, called Standard eco Baustein 1. Unfortunately, you are not allowed to post links. We want to change a few small things if it makes sense. We would like to exchange the exterior walls from 24cm to 36.5 cm, aerated concrete from Porit in monolithic construction. Additional cost about €7300 (the foundation slab will also be larger to maintain the living space) the rest will also be adapted to the stronger walls, roof, windowsills... We would exchange the gas condensing boiler for an air-water heat pump (Vaillant aro Therm Split vwl 75/5) with Unitower vwl 78/5 IS if it is worth it Additional cost €6000 Underfloor heating throughout the entire house. It is the Flair 125 house, the 125 also stands for the m2. 1.5 floors. What is your opinion on this? Best regards Kobi

The thicker stone is okay and inexpensive. The heat pump is a matter of taste, to me these things are not simple and robust enough. And a gas heating system is not only fault-resistant but also quite economical, you won't save the 5000,-, bet? 5000 because the gas connection is omitted. The FHZ is a fine thing, I like it a lot if you go for appropriate floors, ideally tiles or glued vinyl. The Porith stone is okay, its sound insulation is not that good, its thermal insulation very good. When plastering, make sure they paint a silicone facade paint at the end, then it will stay nice and clean for a long time. good luck. K.

Thank you for the tips, that was very very quick.

I have already read a lot about the problems and settings with the heat pump. The reason we still considered buying one were also 2 statements where you end up with about 80€ electricity per month.

I had calculated the gas connection at 2500€, I have to ask again.
6000€ surcharge for the heat pump - 2500€ gas connection I thought (then it would still have been a 3500€ surcharge)

The question is how much does gas cost per month approximately?
Then there would be chimney sweep and gas meter rent and no idea if anything else is added?

We wanted to have vinyl laid everywhere except bathrooms, hallway, and utility room tiles. We just have to find out if the vinyl is really that insensitive - since we also have a dog.

Good tip about the paint is saved

I have already read a lot about the problems and settings with the heat pump.

You just have to get familiar with it first, but then it is not a bad way to heat. My parents have had an air-to-water heat pump for many years and are still very satisfied with the effort and costs. We are also getting one (also building with Town & Country)

Why we still considered buying one were also 2 statements where you get by with about €80 electricity per month.

What does the electricity consumption refer to? Only heating or heating and energy?

We would like to replace the exterior walls from 24cm to 36.5 cm, aerated concrete from Porit in monolithic construction.
Additional cost approx. €7300 (the base plate will also be larger to maintain the living space)

Would the 24 cm walls also have been planned monolithically?