Construction of a two-family house / Selection of heating for the ground floor apartment

Dear Sir or Madam,

we are currently in the process of coordinating/selecting the heating system for our condominium in a two-family house.
We are buying the apartment from a developer who is building the second residential unit for personal use (essentially: building owners' association). Therefore, we have complete freedom regarding the equipment and selection.
The condominium is intended to be owner-occupied for approximately 15 years and then sold.

Here are the facts about the house:

1 residential unit on the ground floor (this is the one we are buying).
Volume: approx. 620 cubic meters
Living area: 172 square meters
Living area + usable area (excluding garage): 235 square meters
Construction to Kfw 70 standard or better
Active living space ventilation with heat recovery – details see below (an offer is available!)
Windows: triple glazing with U-value 1.1 / hardly any load-bearing walls, total window area approx. 15 meters
If further details are required, please just ask briefly

2 residential units on the 1st + 2nd floors
Occupied by the developer.
Living area: approx. 380 square meters + 70 square meters usable area in the basement

Total volume: approx. 2000 cubic meters

Facts on site:

The orientation of the apartment is to the north, the (main) terrace faces west, the second terrace faces east,
It is a house on a slope.
The basement, in which the garages are also located, is at the lowest level.
Here, 35 cm reinforced concrete walls are planned. A 22 cm insulation will be applied on this.
The walls above ground level will be masonry with 22 cm stone + 18 cm insulation.

Questions:

1.) Which heating system is recommended?
2.) Which U-value should be chosen for the windows?
3.) Which ventilation system is suitable?
4.) Are there any specific dealer recommendations in the Stuttgart area to whom we can turn?

Regarding 1.)
Option 1:

There is the possibility of a shared heating system – the current status is: installation of a gas cogeneration plant for both residential units together. Details are not yet finalized.
Addition: If a cogeneration plant makes sense, consideration could be given as to whether the neighboring house (6-family house with 1700 cubic meters) could possibly be supplied via our cogeneration plant.

Option 2:

Each residential unit is supplied separately – currently our favorite!
After extensive research and considering the overall cost situation, we are currently convinced that we will install a gas condensing boiler (e.g. Buderus Logamax Plus) and complement it with vacuum tube collectors for heating support and domestic hot water heating.

Alternative to 2:

- Air-to-air heat pump
- Mini cogeneration plant
- other system (fuel cell, etc.)

Regarding 2:)

According to the construction description, triple glazing with a U-value of 1.1 is planned? There is an offer to reduce the U-value to 0.7 at an additional cost. The surcharge is currently unknown. Is this advisable?

Regarding 3:)

According to the construction description, a ventilation system was not included in the price. However, we want to have such a system installed. We have an offer from the company LANGE Lüftungstechnik.
For our residential unit, the following system is to be installed:
SCHRAG Recoverysmart EC with summer bypass (what is a summer bypass???) including 7 x supply air and 7 x exhaust air connections.
Material costs net: 7,350.00 Euro
Labor costs net: 2,250.00 Euro
Total incl. VAT: 11,424 Euro

So far, no alternatives are available to us.
What is important to us is that the entire house will have a KNX automation installed, so it would be great if the ventilation system could also have a KNX/EIB interface.

Regarding 4.)

Can anyone recommend a dealer for HEATING and VENTILATION SYSTEMS? Windows will be provided by the developer.

Thank you very much for reading this detailed description to the end. I look forward to your suggestions and tips.

Many thanks, André

....Thank you very much for reading this detailed description to the end, I look forward to your suggestions and tips.

A thorough basic investigation and planning is required here! Who is supposed to deal with this topic reliably for free ?:confused: There probably won't be a free savior here, and if there is, the answer is hardly likely to be economically viable ;-)

regards

Here a detailed basic investigation and planning is required! Who is supposed to dedicate themselves to this topic reliably for free ?:confused: There probably won’t be a free savior here, and if there is, the answer would hardly be economically viable ;-)

best regards

Thank you very much for your comment. I consider the house-building forum as an expert forum where experts, if they wish, can support those seeking help with tips and tricks. Of course, I also use other sources such as, for example, an on-site energy consultation. Nevertheless, I firmly believe that there are people who are happy to answer a detailed post from time to time. I made a great effort and wanted to be as precise as possible. I think the questions I asked can be answered very well based on my data. Or is this a purely commercial forum?

Hello,

Or is this a purely commercial forum?

Definitely: no!

Now comes the implied BUT. You receive "hints" - "instructions" - "tips" on this forum, but by no means a free HVAC design.

Since you are using an energy consultation "on site," you will surely receive verifiable answers to your post shortly :rolleyes:

Kind regards

Hello,

Clearly: no!

Now comes the implied BUT. You receive "hints" - "instructions" - "tips" in this forum, but under no circumstances a free HVAC planning.

Since you are using an energy consultation "on site," you will certainly receive verifiable answers to your post shortly :rolleyes:

Kind regards

Thank you very much for your hint. I will wait and see. Perhaps I have slightly overestimated the possibilities and knowledge of the forum members. In principle, I expected solid answers to 4 questions and described the project in order to receive them as qualified as possible.

Obviously, however, this was a bit too much to ask. Of course, we are doing the planning ourselves, but it is better to approach such planning with prior knowledge than to let craftsmen "talk you into" something. Instead of answers, however, only hints that the case is too complex.

..... Perhaps I overestimated the possibilities and knowledge of the forum members a little.

If you had made a little effort using the search function, the essentials should have become clear when studying comparable questions. Without sufficient basic investigation, no reliable or usable answer is possible.

..... In principle, I had expected viable answers to 4 questions and to receive these as qualified as possible, I described the project.

This attitude is somewhat presumptuous. :mad:

..... Apparently, this was a bit too much to ask after all.

That’s right, otherwise you have to consult a clairvoyant

..... We naturally do the planning ourselves, but it is better to go into such planning with prior knowledge than to let craftsmen "talk you into" something.

Well then, let the planning, which begins with the basic investigation, be done. It is completely independent of any craftsman. With the resulting parameters, the appropriate system builder is then sought. "Talking you into" something is thereby excluded ;-)