Hello everyone!
As is well known, construction cost calculations during the planning phase are based on the gross volume (BRI) and/or the gross floor area (GFA). This applies to all floors of the house, including any basement level.
Considering a basement with typical example values, the costs are as follows:
- based on BRI: 90m² (970 ft²) x 2.7m (8.9 ft) x 340 EUR/m³ = 82,620 EUR
- based on GFA: 90m² (970 ft²) x 960 EUR/m² = 86,400 EUR
- on average, therefore, about 84,510 EUR.
On the other hand, additional costs for a basement are often estimated at around 40,000...55,000 EUR, depending on the equipment and waterproofing.
The sheer scale of these differences causes confusion.
This raises three questions:
1) How do these values relate to each other?
2) What has been the experience of previous homeowners who know the actual costs retrospectively?
3) A partially open basement level on a sloped site is considered a ground floor. In this case, is the calculation always based on BRI/GFA, or is the distinction more between living and utility spaces?
As is well known, construction cost calculations during the planning phase are based on the gross volume (BRI) and/or the gross floor area (GFA). This applies to all floors of the house, including any basement level.
Considering a basement with typical example values, the costs are as follows:
- based on BRI: 90m² (970 ft²) x 2.7m (8.9 ft) x 340 EUR/m³ = 82,620 EUR
- based on GFA: 90m² (970 ft²) x 960 EUR/m² = 86,400 EUR
- on average, therefore, about 84,510 EUR.
On the other hand, additional costs for a basement are often estimated at around 40,000...55,000 EUR, depending on the equipment and waterproofing.
The sheer scale of these differences causes confusion.
This raises three questions:
1) How do these values relate to each other?
2) What has been the experience of previous homeowners who know the actual costs retrospectively?
3) A partially open basement level on a sloped site is considered a ground floor. In this case, is the calculation always based on BRI/GFA, or is the distinction more between living and utility spaces?
B
Bauexperte28 Feb 2013 12:39Hello,
It is good for you that you know the construction cost index; it is determined quarterly by the Federal Statistical Office based on available data, excluding value-added tax, and is not binding for contractors. It is mainly used by insurance companies to calculate building insurance.
You invited me to this discussion via private message – I am slowly wondering why, as you do not seem to want to read answers, but rather want your engineer’s opinion to be confirmed. If you have followed my posts here – which I assume you have, otherwise you would not have asked me to reply in your thread – you will have noticed that I always distinguish between actual construction costs and typical incidental construction costs. Therefore, the €233,000 mentioned or proposed by your architect will, in my experience, not be sufficient for your construction project. And yes, I know there are significant differences – even within the Rhineland; one recent example of this kind of contractor was IBG. To this day, I do not understand why a considerable number of well-off and high-earning builders awarded this contractor the contract. But probably their undoubtedly existing intelligence outsmarted itself.
I would rather say it will look like this:
Single-family house according to the Energy Saving Ordinance with partial basement: €235,000
KfW 70 standard: between €12,000 and €20,000 depending on the desired technology or additional efforts using the 15% rule
Incidental construction costs: €35,000 to €40,000
Additional foundation costs due to hillside location: €10,000
Painting work/floor coverings in turnkey delivery: €15,000
Outdoor facilities: €15,000
By the way – to answer your question from the other thread, which surprised me: there are associations of engineers you can find by entering the relevant parameters via Google. You can also commission €uro; I seem to recall you are not that far apart in terms of kilometers.
Best regards from the Rhineland
YvesB schrieb:
Of course, the mentioned €233,000 is not enough for the construction project, as this only covers the pure construction costs, with additional incidental construction costs (about €35,000) and other costs for the land, preparation, etc. (about €70,000). Our basement will be built with brick masonry.
Jena is not far away, but we are building in a completely different area around Gera – yes, there are such significant regional differences.
It is good for you that you know the construction cost index; it is determined quarterly by the Federal Statistical Office based on available data, excluding value-added tax, and is not binding for contractors. It is mainly used by insurance companies to calculate building insurance.
You invited me to this discussion via private message – I am slowly wondering why, as you do not seem to want to read answers, but rather want your engineer’s opinion to be confirmed. If you have followed my posts here – which I assume you have, otherwise you would not have asked me to reply in your thread – you will have noticed that I always distinguish between actual construction costs and typical incidental construction costs. Therefore, the €233,000 mentioned or proposed by your architect will, in my experience, not be sufficient for your construction project. And yes, I know there are significant differences – even within the Rhineland; one recent example of this kind of contractor was IBG. To this day, I do not understand why a considerable number of well-off and high-earning builders awarded this contractor the contract. But probably their undoubtedly existing intelligence outsmarted itself.
YvesB schrieb:
Applied to our example, this means for the living floors 130m2 x €1,300/m2 = €169,000 and for the basement 65m2 x €800/m2 = €52,000. That makes a total of €221,000 for pure construction costs.
I would rather say it will look like this:
Single-family house according to the Energy Saving Ordinance with partial basement: €235,000
KfW 70 standard: between €12,000 and €20,000 depending on the desired technology or additional efforts using the 15% rule
Incidental construction costs: €35,000 to €40,000
Additional foundation costs due to hillside location: €10,000
Painting work/floor coverings in turnkey delivery: €15,000
Outdoor facilities: €15,000
By the way – to answer your question from the other thread, which surprised me: there are associations of engineers you can find by entering the relevant parameters via Google. You can also commission €uro; I seem to recall you are not that far apart in terms of kilometers.
Best regards from the Rhineland
Bauexperte schrieb:
... I’m starting to wonder why, since you don’t want to read answers but rather have your engineering opinion confirmed. If you have been following my posts here—and I assume you have, otherwise you probably wouldn’t have asked me to reply in your thread—you will have noticed that I always distinguish between construction costs and typical ancillary building costs. ...If it came across that way, that was not my intention, Bauexperte, and there was no engineering opinion involved. I actually wanted to address someone with real-life experience in home building right away.
Ultimately, your comments answered my question on this topic. So, some clarity was brought regarding different approaches to cost planning. Your approach turned out to be the practically understandable one compared to the general estimation I initially mentioned, although both can lead to similar totals in specific cases by chance.
In that respect, it was actually a good idea to invite you to respond directly, since this topic likely would not have been answered by the broader community here in the forum.
Best regards from Thuringia!