ᐅ Is this masonry construction sufficient for KfW55 standards?

danixf schrieb:

We have a similar construction, and next time I would choose sand-lime brick. Houses made with aerated concrete are extremely noisy in comparison.

I can fully agree with that. 🙄
Sign, seal, stamp, apostille, and dance my name around the certificate. 😀

danixf schrieb:

If you can live with it, then the construction method is definitely acceptable.

I can barely live with it.

The financial aspect is irrelevant.

kati1337 schrieb:

I can fully agree with that. 🙄
Sign it, seal it, stamp it, apostille it, and dance my name around the document. 😀

I can barely live with that.

kati1337 schrieb:

I can fully agree with that. 🙄
Sign it, seal it, stamp it, apostille it, and dance my name around the document. 😀

I can barely live with that.

Calcium silicate blocks only for the interior wall? Calcium silicate blocks have poor thermal insulation.

MeinHaus45 schrieb:

Calcium silicate brick, but only for the interior wall? Calcium silicate brick has poor thermal insulation.

Then you just add some insulation wool in there. 😀
It’s a matter of personal preference. Is the house located in a new development area? On a busy street? What are the neighbors like?
The real question is how well you handle noise. The fact is that with this wall construction, you will definitely be able to clearly hear a passing car.

MeinHaus45 schrieb:

Sand-lime brick only for the interior wall? Sand-lime brick has poor thermal insulation.

Sand-lime brick can of course be used for exterior walls as well! Just add appropriate insulation (you can also use the 2cm (1 inch) air gap) and that's it.

Yes, you will probably need to increase the insulation to 18cm (7 inches). I would also recommend using calcium silicate bricks if you are already going for a double-wall construction.

First of all, for a reliable answer, it is important to know whether you plan to build, for example, a two-story city villa or a bungalow with the same living area. The city villa has a significantly better surface-to-volume ratio (A/V), which allows the building envelope to perform better even with slightly higher U-values. We have a bungalow just over 90m² (970 sq ft), with a lower proportion of windows facing south, west, or east. Therefore, solar gains are minimal (this was intentionally planned). Windows have a U-value of 0.81, exterior walls are made of sand-lime brick, 17.5cm (7 inches) thick plus 20cm (8 inches) of mineral wool insulation with a thermal conductivity of 0.035. The floor heating has 13cm (5 inches) of insulation at 0.032, and the ceiling is insulated with 24cm (9.5 inches) of mineral wool between the rafters (0.035) plus 6cm (2.5 inches) under the rafters. This setup meets the U-value requirements for the building envelope according to KfW Efficiency House 55 standards. Additionally, we use an air-to-water heat pump, which brought us to the KfW Efficiency House 55 EE standard. Furthermore, we voluntarily installed a 13.68 kWp photovoltaic system cost-effectively during the construction phase.