Composition of flat rates for house construction

Hello everyone,

I also plan to embark on the adventure of "building a house" in the near future. Unfortunately, I am still quite a novice in this field, so at the moment there are many more questions than answers...

According to my findings, in the initial rough estimate of the expected construction costs for a single-family house, flat rates are apparently very often used, for example 300 € per m³ of enclosed space or 1,500 € per m² of living space.

How are such flat rates composed? Are there guidelines on how these approaches are distributed across the individual trades (shell construction x%, roof y%, heating z%, etc.)?

Or put differently, how are the total construction costs distributed percentage-wise across the individual trades?

What is your assessment? I am well aware that these can only be very rough estimates, but the flat rates mentioned above are, after all, just that.

I am grateful for any assessment.

Best regards Markus13

Hello,

How are such flat rates composed?

Many years of experience

Are there any guidelines on how these approaches are distributed across the individual trades (shell construction x%, roof y%, heating z%, etc.)? Or, in other words, how do the total construction costs percentage-wise distribute across the individual trades?

Apart from the fact that such an assessment is not possible – every single-family house is different – what benefit do you think you could gain from such a breakdown?

... but these are after all the flat rates mentioned above, too.

No, €1,500.00/sqm/living space is a very realistic value for the new construction of a single-family house, built according to the valid Energy Saving Ordinance with a gas condensing boiler and solar domestic hot water heating. Everything below that should be viewed with caution – everything above depends on the technology and equipment used.

Keeping this reference point and the truth in mind that a closed shell should never be paid for with more than max. 58-60% of the total building sum will get you further than any poorly thought-out allocation of the 13 trades into percentages.

Best regards

Hello,

thank you very much for this assessment, it already helps me to some extent.

What does "geschlossener Rohbau" mean in this context? Earthworks, all masonry work (with brick cladding?), roof structure with covering as well as windows and doors?

Best regards
Markus13

Hello,

What does "geschlossener Rohbau" mean in this context? Earthworks, all masonry work (with brick cladding?), roof frame with covering as well as windows and doors?

A "geschlossener Rohbau" means: earthworks (usually stripping the topsoil; sometimes also backfilling + compacting – as far as the material is suitable), exterior and interior masonry, carpentry, roofing, and the trade of windows including the front door.

The facade (plaster or cladding) is only applied after the completion of the window trade; a classic 10% deduction in most payment plans.

One speaks of a "veredelter" Rohbau when the facade is also completed. This option is usually chosen when all interior work is subcontracted or carried out as EL.

Kind regards

That was very quick, thank you very much.

Could you possibly give me an estimate of what proportion of the architect's fee according to HOAI is appropriate for service phases 6 to 9 if the architect only accompanies the construction up to the closed high-end shell construction? 50%? (Standard single-family house without special extras).

An approximate guideline would already help me a lot.

Regards
Markus13

Hello,

Could you perhaps give me an estimate of what proportion of the architect's fee according to HOAI for service phases 6 to 9 is appropriate if the architect only oversees the construction up to the completed shell with finished interior? 50%? (Normal single-family house without special extras).

You can easily read the expected costs from the fee table

Kind regards