kfw40plus monolithic solid - tips/experience?

You write that with a 0.07, e.g. Ytong, a 0.16 U-value of the wall could be achieved. I assume you mean a 42 cm thickness as the basis? I already wonder... is that enough? I googled a requirement here that at least a 0.15 U-value must be met. Is it possible to somehow compensate a little for the missing insulation value?

And again my question. I was told that the 0.07 stone, whether Poroton or Ytong, is very porous and must then be reinforced extensively. Can anyone confirm this?

What do you mean by "I am at the source"? A photovoltaic calculation is an island project. My specifications are roof, orientation, budget, and also the conditions that must be met, e.g. self-consumption rate and feed-in limitation. All of this should also be economical. I can calculate that. With "my" system I overshoot the target by far. The system has about 500% higher capacity than required and the storage is about 3 times larger than required. Only to what extent and whether this has a positive effect on the calculation and achievement of the kfw40+ standard no one tells me. The contractors consulted each refer to an internal complex calculation after I have signed, the energy consultant and passive house planner want money first for the calculation, with uncertain result.

You write that with a 0.07, e.g. Ytong, a 0.16 U-value of the wall can be achieved. I assume you mean a 42 cm thickness as a basis?

Yes.

I am already wondering... is that enough? I googled a specification here that at least 0.15 U-value must be met. Can the slight lack in insulation value somehow be compensated?

A single-family house consists of more than just the sum of its 4 walls + roof; the sum of all measures (masonry, insulation, windows, thermal bridges, etc.) must later achieve the required U-value.

And again my question. I was told that the 0.07 block, whether Poroton or Ytong, is very porous and must be reinforced extensively afterwards. Can anyone confirm this?

I know that our builders curse when they have to install the hollow bricks. But it cannot be that bad, otherwise they would outright refuse to use the bricks—whether filled or unfilled. Aerated concrete, on the other hand, is very easy to handle; nothing crumbles, otherwise quite a few single-family houses in Germany would pulverize sooner or later.

Could it be that the builders you asked usually work with another brick (perhaps sand-lime brick) or are not yet familiar with the KfW 40 requirements?

What do you mean by "I sit at the source"? A photovoltaic calculation is an isolated project planning. My specifications are roof, orientation, budget and of course the requirements that must be met, e.g. self-consumption quota and feed-in limitation. All this should also be economical.

Oh—learned something new; I thought through your work you also had contacts with energy consultants. If that is not the case, ask at the energy agency or look for energy consultants in the relevant associations. A second offer never hurts.

Rhenish greetings

yes, I also suspect by now that the BU I inquired about is not yet familiar with kfw40+. However, according to their own statements, both mainly build with Ytong. I just discovered the kfw 431. Here, 50% of the "construction supervision" is reimbursed and there is a list of energy consultants available. Apparently, there are 36 of them within a 5km radius. I have made contact. Let's see what comes of it. Yes, and again. My original question was whether I can compensate for a worse wall with other components, e.g. a better insulated basement than usual or better insulation under the floor slab or a better insulated roof or even better windows... or with energy measures such as the 200% plus energy house. Of course, the house does not consist of just one wall - but I am being led to believe that the wall must reach a coefficient of 0.15 in any case. If it is above that, the wall is excluded!? So that does not seem to be the case?

Hello everyone, we are planning a house in the Allgäu. Since it will not be small and includes 3 residential units, we would like to use the kfw40plus subsidy. The photovoltaic system is already extensively planned (the entire roof), so that is already set. In addition, a water-guided masonry stove.

Hello,

we are almost in the same position or rather considering and looking in all directions. We are also planning KfW 55 and 3 residential units. That alone is already a special challenge (residential building class III, 3 ventilation systems, ...)

We also want and will build monolithically and do not want external insulation.

We had a very extensive meeting with our architect and structural engineer on Wednesday. But there is still a lot of uncertainty or undecided matters.

Currently, we have a team consisting of an architect, structural engineer, checking structural engineer, and KfW energy consultant.

We also consider questions such as what if 40 or 40+ for example. The subsidy is quite substantial.

In addition, I am currently researching all programs from the BAFA that might be relevant.

Important: the 50% subsidy for the energy consultant is available only from April 1, 2016.

We are happy to exchange our experiences here in the usual way. With such a project, you quickly get annoyed if you have overlooked or did not know something in advance.