ᐅ Planned house construction – garage/workshop on the ground floor with living space above

Hello everyone,

I am planning to build a house next year. The lower level will only have storage space for an RV, cars, a tipper truck, a technical room, a small storage room, and the entrance including the stairwell. The living area will be upstairs. The floor plan is approximately 14.5 x 12 meters (48 x 39 feet), and the ceiling height downstairs should be 4 meters (13 feet) to accommodate the RV with a 3-meter (10 feet) entrance height, although 1.5 meters (5 feet) of that height will be lost due to the slope. Upstairs, I want an exposed roof truss with about a 20-degree roof pitch.

I have a few questions:

For the lower level, I am considering using double concrete walls. Has anyone had experience with this? What about government energy efficiency funding (KFW) if I only insulate the ceiling? Or would you insulate everything? The roller doors would be the weakest point in terms of insulation.

Upstairs, I plan to use filler block bricks (Poroton). Are there significant differences between the various manufacturers like Schlagmann, Wienerberger, Unipor, etc.?

On top of that, there will be an exposed roof truss. Would you recommend a double roof truss with insulation between the rafters, or the use of prefabricated insulated panels? Since I want to apply for a KFW loan, I am wondering if insulation between rafters is sufficient?

Thanks in advance for all the answers.

Best regards,
Niederbayer

Concrete double walls are also available with internal insulation, commonly referred to by most manufacturers as "thermal walls." Maximum heights are usually around 3.5 meters (11.5 feet). What about your budget and the possibility of obtaining building permits / planning permission?

Insulating the upper part while leaving the underside uninsulated would be the approach I would consider first. The underside of the living area will then be the challenge. Access from below or from the side?

rick2018 schrieb:

Concrete double walls are also available with internal insulation, often called Thermowand by most manufacturers.
Maximum heights are usually around 3.5 meters (11.5 feet).
How about your budget and building permit/planning permission?

Thermowand: installation is possible, but it will lead to permanent condensation at the roller doors, and the price is quite high.
Budget: fits.
Building permit/planning permission: according to the building plan, there is no objection to having one story at 4 meters (13 feet).

hampshire schrieb:

Insulating only the upper part and leaving the lower part uninsulated would be the approach I would take first. The underside of the living area will be the challenge. Entrance from below or from the side?

Exactly. I'm worried about the transition from the walls to the ceiling – dew point in the concrete.
Entrance from below. But the stairwell doesn’t necessarily have to be heated.

The KfW requires compliance with the Energy Saving Ordinance.
In this case, DIN 18599 applies.
Through zoning, you have separated the non-residential area from the residential area.