Cost calculation for the new construction of a multi-family house

  • Erstellt am 2017-03-19 15:39:45

Michael30

2017-03-19 15:39:45
  • #1
Hello,

I have already tried the search function but did not find the answer that suits me. So I hope you can help me.

I am currently planning the new construction of a multi-family house to replace an existing old building. The old building is directly attached to a multi-family house built in 2006, which is also how my planned new building should be done.

Here are a few facts (many measurements are derived from the already existing building):

Maximum dimensions: 12x12 m
Resulting floor area: 144 m2
Building height (gable): approx. 11 m
Floors: 2 + attic + basement
Number of planned apartments: 3 - 5

My question now is: How do I calculate the expected costs? I have already been to the architect who made a first estimate based on volume (€430 per m3). On the internet, I also found calculations based on the area. However, I do not quite understand how, for example, the basement or a balcony is included. What influence does the number of apartments have? Which option is preferable: volume or area? Maybe you can bring some clarity here.

For now, I am only concerned with the costs for the building itself; garages and parking spaces are another matter.

Thanks in advance!
 

11ant

2017-03-19 20:49:18
  • #2
Whether you use cubic or square meter comparative values does not matter as long as you stay within the usual range of room height. If you want to adjust for new construction using old building room heights, you must of course take into account that the comparative values are usually based on clear room heights of 2.5 to 2.65 m.

In any case, I would calculate with real numbers, i.e., with true measurements. That areas and volumes specified according to standards such as attic rooms, balconies, areas of and under stairs, etc., sometimes differ does not make them cheaper to build. Therefore, I would count all building volumes fully (and not forget the underground ones either!).
 

Peanuts74

2017-03-21 15:13:40
  • #3
430 €/m³ seems quite a lot to me. About 3-4 years ago, we calculated between 300-320 € (in the mid-range). It is really hard to calculate precisely with such flat rates anyway. But you can, for example, take the dimensions to a general contractor and have a rough draft made. You will then get a fairly accurate figure of what the building with the equipment xyz would cost.
 

Michael30

2017-03-21 20:34:43
  • #4
Thanks in advance for the answers.

I have now calculated three variants:

1. Real volume

I tried to determine the space as accurately as possible and came up with 1.617 m3, which, at €430 / m3, amounts to just under €700,000. This is roughly the calculation the architect made during the first conversation.

2. Real area

I have 2 full floors + basement + attic, which results in a total area of 576 m2. Calculating with €1,400 / m2 (figure found online – realistic?) I come to about €800,000. However, this does not take into account that the attic is not a full floor.

3. Living area

The architect once gave me a figure of 290 m2 of living space. Unfortunately, I cannot currently trace how this was calculated (which is not unimportant for calculating rental income). If I multiply these 290 m2 by €2,200 / m2 (again from the internet – realistic?), I come to just under €640,000.

Looking at your answers now, I would assume that the first variant is the most reliable. Comments are very welcome

: Where did you build? Could these be regional differences? At the end, were the €300-320 at least roughly correct for you?

Best regards,
Michael
 

11ant

2017-03-21 20:57:16
  • #5
There could be a causal connection with the fact that you probably calculated that one most accurately. For variant 2, I would find it sensible to take the sloping walls into account (and thus also the partial consideration under 2m) – only regarding the areas under 1m height, I would not follow the norm’s reasoning in ignoring them. A very important lever, however, remains the standard – i.e., realistically assessing how many points one’s own taste might be more expensive than that of the average consumer. On that depends whether the value with which you multiply the room or the area "fits". Wrong index equals wrong result. Nasty point calculation
 

Peanuts74

2017-03-22 07:04:01
  • #6
We built in Saarland, 1.5 floors (approx. 135m^2) plus a basement, where everything is tiled and there is an office/guest room. The whole thing has approx. 830 m^3 and just the house turnkey (i.e. our EL combined) including painter and floors would have cost about 260-270 k€. Included are a guest bathroom with shower, heat pump, controlled residential ventilation, electric shutters, Cat and satellite connections everywhere, ceiling spots (approx. 30), lamps only LED, partly dimmed and remote controlled etc. So no luxury, but also not Town & Country standard. In the end, 320.- was about right.
 

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