1 1/2-story or 2 full floors

Hello everyone,

after reading through various topics here in the forum over the past few months, I would now like to join the list of topic starters.

According to the current status, we are still in the absolute very early planning phase. Here are a few facts first.

Plot of land (approx. 330sqm) available, additional 330sqm usable as garden.
Construction of a single-family house in Kfw70 (approx. 260,000 €), gross floor area approx. 100sqm, brick-clad, roof pitch 45° gable roof, max. ridge height 12.5m, with own work on electrical installations, floor and wall coverings, and other smaller services (but as said, still in the planning phase :cool .

We have now had the first two appointments with our architect, who would like to build parallel with us on the neighboring plot. There are already two "system plans".

Now to our actual question:

We possibly want to build 1 1/2 stories, with a basement, the upper floor expanded with dormer windows according to the room layout. Possibly attic expansion reserve (ceiling between upper floor and attic as a solid concrete ceiling).

Our architect said that 2 full stories cost almost as much as 1 1/2 stories. Since the attic is then very large (the roof has a 45° pitch), one could also, for example, house the heating here. A basement might become very expensive, as there might be quicksand (but this still needs to be checked with a soil report (in any case, a foundation slab sank the day after nearby)), in which case the basement would be omitted.

Have you been able to gain any experience regarding this????

Many thanks in advance and enjoy the rest of your Sunday.

Carsten

The price difference is indeed likely to be small, but there are reasons why houses with 2 full floors and a square floor plan generally have flatter roofs. Here is a sample of how that could look in your case:

Hello,

thank you very much for the reply. Unfortunately, we are bound to the 45° roof pitch according to the development plan. But the house should not be purely square, it should have a few other "corners and edges" (protrusions and recesses).....

Regards

Hello Carsten,

Plot (approx. 330 sqm) available, a further 330 sqm usable as garden.
Construction of a single-family house in KfW70 (approx. 260 T€), gross floor area approx. 100 sqm, brick-faced, 45° pitched gable roof, max. ridge height 12.5 m, with own contribution for electrical work, floor and wall coverings and other smaller services (but as said, still in the planning phase :cool .

So round about 160 sqm living space. As a single-story KfW 70 efficiency house with clear structures and approx. 1.20 m knee wall, brick-faced and with a usable basement you will probably have to invest around TEUR 290 including own electrical work. Plus ancillary construction costs and reserve for additional foundation costs, plus garage, plus painting work and floor coverings, plus outdoor facilities and plus extra reserves. I would estimate that you have to expect a total volume of around TEUR 380.

Our architect now said that 2 full floors cost almost as much as 1 1/2 floors.

"Almost" is relative – going from a 1.20 m knee wall to a full floor already costs several thousand euros.

Since the attic is then very large (roof has a 45° pitch), one could also, for example, accommodate the heating here.

Is that your idea or your architect’s? If the latter, hopefully they have also explained to you the additional efforts and thus extra costs associated with this idea?

... in any case, in the nearby area a slab foundation already sank the next day...

That’s what happens when you save at the wrong end, for example on a new kitchen

Best regards

Hello Carsten,


So round about 160 sqm/living space. As a single-story KfW 70 efficiency house with clear structures and about 1.20 m knee wall, with cladding and a usable basement, you should expect to spend around TEUR 290 with EL electrics. Plus ancillary construction costs and reserve for additional foundation costs, plus garage, plus painting and flooring, plus outdoor facilities and plus extra reserves. I would estimate that you have to plan for a total volume of around TEUR 380.


"Almost" is relative – increasing from 1.20 m knee wall to a full story already costs several thousand euros.


Is that your idea or your architect’s? If the latter, hopefully they also explained the additional expenses and thus additional costs associated with this idea?


That’s what happens when you save in the wrong place, for example on a new kitchen

Kind regards

Hello Bauexperte,

thank you very much for your answers. Unfortunately, it took me a little longer to get back to you

The story about the "slab" is unfortunately not correct, I expressed myself wrongly there. What is sunk is a basement slab. In the area, many houses with a "normal" slab (without a basement) have also been built, without adding another foundation. So the burden will probably pass us by.

The 45° roof pitch does not come from our architect either; it is unfortunately stipulated in the development plan.

In your experience, how big is the "relative" cost difference between one-and-a-half stories with dormers and two stories?

Thank you in advance for your answer, and have a nice rest of the week.

Carsten