ᐅ Building Envelope KfW 55

Hi,

my 120 sqm (1290 sq ft) house will have 24 cm (9.5 inches) Poroton bricks and 12 cm (5 inches) rigid foam insulation.
There will be 24 cm (9.5 inches) collar beam insulation and 5 cm (2 inches) insulation under the floor slab.

Is this a good setup?

I found some additional information.
The floor slab insulation consists of Styrodur C rigid foam boards with a thermal conductivity of 0.035 W/(m·K), installed on a finely leveled base and covered with a polyethylene (PE) sheet as a protective layer.
Below the insulation, a stainless steel ring earth electrode is planned.

The facade insulation uses rigid foam boards with at least a thermal conductivity of 0.040 W/(m·K), applied in multiple layers with plaster and fleece reinforcement, plus a top coat plaster with a grain size of 2–3 mm (0.08–0.12 inches).
Insulation boards are installed around the base area (damp-proof course level).

Roof insulation
Between the rafters and collar beams in the converted attic area, a 24 cm (9.5 inches) thick mineral wool insulation with a thermal conductivity of 0.035 W/(m·K) is specified.

What do you want to hear now?
Is it possible to achieve KfW 55 with this?
What does your contract say? If KfW 55 is guaranteed there, then your builder must ensure that it is met.

Der Da schrieb:
What do you want to hear now?
Whether it’s possible to achieve KfW 55 with that?
What does your contract say? If KfW 55 is guaranteed here, your builder has to make sure it fits.

Of course, KfW 55 is guaranteed.

I just want to know if the measures are good or if any experts here have objections 😉

Hello,

Nutshell schrieb:

I just want to know if the measures are good or if any objections from the experts here come up 😉

How are we supposed to know that? You have only provided the bare minimum information about the new build, the orientation of the plot in relation to the sun is unknown, the technology to be installed (which is likely substantial for a 24cm (9.5 inches) wall), and so on.

If your provider has contractually guaranteed KfW 55 standard, they are also obligated to comply with it. Furthermore, an independent expert must be involved in the construction project; they should intervene if something is not executed correctly.

Regards, Bauexperte

Bauexperte schrieb:
Hello,


How are we supposed to know? You only provided the bare minimum information about the new build—the orientation of the plot in relation to the sun is unknown, the installed systems (which might be quite extensive for a 24 cm (9.5 inch) masonry wall), and so on.

If your supplier has contractually guaranteed KfW 55, they are legally obliged to meet that standard. Furthermore, an independent expert must be involved in the construction process; they should intervene if anything is not executed correctly.

Regards, Bauexperte

Oh, okay.
The house faces southwest from the terrace side, which has four floor-to-ceiling windows.
Underfloor heating will be installed throughout the house except for the utility room.
The heating system will be a gas condensing boiler combined with 5 m² (54 ft²) of flat solar collectors.
A decentralized ventilation system, Lumos E2, will also be installed.