New construction planning - Am I calculating incorrectly?

Hey, since you have already dealt with the topic, I have a few questions for you.

3. you need a roof window -> A small one in the bathroom, later one in the attic! Is that enough?

Please search according to DIN 18160, Part 5 "Facilities for chimney sweep work." It describes what you need and probably also how big the window must be so that the chimney sweep can move outside. It could also be that you can make it accessible from below (without a window). Then, as far as I know, you must provide a ladder that can be hooked onto the roof and corresponding steps up to the chimney.

4. you need a few steps -> Ok, we don't have any. approx. Prices?

Depending on the location of the exit window and the chimney, you need different numbers. You can find prices on the internet. Depending on the provider, the extra charge for installation will vary. Cheap providers usually make their profit on such additional services.

5. if the roof pitch is unfavorable, the chimney must be correspondingly higher and the chimney sweep needs an attached ladder -> Roof pitch 40 °, the chimney should be in the middle of the house.

See again DIN 18160. With a centrally located chimney, the problem with the ladder probably won't occur. For us, just the ladder alone would have cost 700€.

6. The chimney also needs air. In airtight houses, this means best an external air supply to the chimney -> Hm, honestly. I have not thought about it at all yet.

The supply air is simply fed from outside via a KG pipe with a grille under the floor slab to the chimney. Depending on whether it then only stands outside as a pipe on the house or should be nicely concealed, it costs more or less. What I don’t know is how that looks in combination with a ventilation system.


In the many discussions with our home builder, we have already learned most of the prices in advance and then chose what was most important to us in order to stay within budget. We also had that written into the offer right away. The chimney was one of those things where we originally said we would have it prepared and buy the chimney ourselves later. But since the same topic came up with the kitchen ("old one stays, new kitchen comes later"), garage ("if it fits in the budget, we'll do it now, otherwise later"), we deliberately decided to completely do without the chimney. If necessary, we’ll add an external chimney later sometime.

If I understand you correctly - TEUR 280 - 47 - 40 - I come back to about €1,500.00 per sqm/living space for a KfW 70 efficiency house (with "only" TEUR 30 for secondary construction costs as a deduction to about TEUR 1,600.00/sqm/living space). In that respect, my cost estimates are quite accurate, aren't they?

We oriented ourselves on your listings for the planning. :) I think the secondary construction costs will be somewhat lower for us than your 30-35T€ + 8T€ contingency, but that will vary from plot to plot. Also, for us, exterior facilities and material costs for floor coverings and painting work are included. If you do your calculation without these items, we come to about €1350.

Loft ladder

I find that cheeky, it should actually be part of the scope of services.

I just dug out the offer and the construction service description again. For the city villa, it is not included; for a 1.5-story house, it would be included.

The shower enclosure also has nothing to do with the house construction service. Besides, there are countless models – how should a fixed price be reasonably calculated without upsetting the builder? Many people today also buy floor-level showers, where you don’t need a shower enclosure but a privacy wall – then you can save yourself the trouble with limescale water.

Then what is the difference compared to the 15cm high shower tray?? I don’t need that with the floor-level shower either. The fact that hardly anyone takes the standard plastic shower enclosure anymore is no reason to omit it. If I want to take the turnkey or perhaps even paint-ready house as it is in the standard, I also want to be able to shower.

That is the reason why my cost estimates always include TEUR 10 for extras. I barely know any builders who don’t give in at this point during the sample selection ;)

I believe the 10T€ will not be enough for us; we have given in too many times at too many points, and even before the sample selection, we had already had some points such as the floor-level shower included in the original offer. :(

Hello Musketier,

I think the additional construction costs will be somewhat lower for us than your €30-35K + €8K safety margin, but that will vary from plot to plot.

Yes, the public fees, house connections, and landfill costs vary from state to state.

In addition, for us outdoor facilities and material costs for flooring and painting work are included.
If you calculate without these items, we come to about €1350.

That is the advantage of the East; it is sincerely granted to you ;)

What is then the difference to the 15cm?? high shower tray? I don’t need that either for the floor-level shower.
The fact that hardly anyone takes the standard plastic shower enclosure anymore is no reason to omit it.
If I want to take the turnkey or perhaps even paint-ready house as it is in the standard, I also want to be able to shower.

You can shower without a shower door too. If the floor-level shower, as often, is set against the wall – or also positioned in a “T” shape – with a depth of 1.20-1.30 m, a one-sided tiled privacy wall (height 2.20 m) is enough and no water splashes out. This has – besides the elimination of the annoying duty to clean these shower doors – the decisive advantage that you no longer feel cold when you turn off the tap; the temperature in the bathroom is the same everywhere.

I believe the €10K won’t be enough for us, we have become too weak in too many areas and even before the sample selection we had some points included in the original offer, e.g. floor-level shower. :(

That belongs in the category of self-discipline ;) Although, a floor-level shower really doesn’t cost the earth; somewhere in the range of €5-600 depending on the provider, plus 3 sqm gypsum boards and 3 sqm additional tiles.

Rhenish greetings