Single-family house with 2 residential units for KFW funding

We are also currently building monolithic KfW40 and doing a lot ourselves, but in my opinion it hardly pays off. We took advantage of the subsidy because we had planned anyway with [KWL], [PV], and thick insulation in the roof. What you cannot do yourself and still becomes disproportionately expensive are, for example, the windows.

How or with what do you insulate your roof, I would be interested?

So in the end, can one say that a monolithic structure (let's just stick with KFW55 to tone down the KFW40 discussion a bit) becomes more expensive than if I use 175mm Poroton bricks and then stick Styrofoam on afterward?

So, can one finally say that a monolithic construction (let's say I just stick to KFW55 to tone down the KFW40 discussion a bit) becomes more expensive than if I take 175mm Poroton bricks and then glue Styrofoam in front?

It depends on the time periods you calculate over. Our neighbors are currently renovating the façade insulated in the 1990s. Everything off once and completely new. Just the disposal costs bring tears to your eyes.

So in the end, can one say that a monolithic construction (let's just stick to KFW55 to tone down the KFW40 discussion a bit) is more expensive than if I take a 175mm Poroton brick and then glue Styrofoam on it afterwards?

That is not a clever question. This question, from my point of view, is rather like starting the selection of a car based on the number of cylinders. What I mean is: As long as you are not doing the masonry yourself, completely different questions are in the foreground.

Among other things: Development plan Surroundings (soundproofing can also be an issue) Best to find a company that suits you personally (you better never present a company with a specific brick! They should install what they always use and have experience with. The two questions before are only introductory because they can influence the choice of the company. For example, if clinker is specified and a company has zero experience with it, another company would probably be better suited). So. But even here, the questions about which company is actually the right one are still not included. Which again depends on the property and the planned house. Therefore: the brick question is actually not even relevant here yet.

So in the end, can one say that a monolithic building (let’s just stick with KFW55 to calm down the KFW40 discussion a bit) is more expensive than if I take a 175mm Poroton brick and then glue Styrofoam on the outside?

If you want to build EH55 (for which there is no longer KfW support), you are better off with monolithic not only in terms of quality but also cost. ETICS requires exemplary even masonry with plaster facade, which almost excludes amateur DIYers. KfW-compliant EH40 means you have to pay very close attention to the U-value, and for that you end up with noticeably thicker walls with any constructive wall builder than with insulation stuff.

Our neighbors are currently renovating the facade insulated in the 1990s. Everything is being removed and redone. Just the disposal costs bring tears to your eyes. Both are in their late sixties and are doing this mainly to make the house fit for the children—or for a sale.

Nonsense with (bags) sauce. Children in their mid-forties rarely dream of returning to their childhood hometown (including buying out their siblings), just because their parents brought them to home ownership there. A buyer worst case in over twenty years (if the last surviving parent only leaves the house then) will get no discount on the then applicable renovation obligations just because a bit in this direction (= Standard GEG2025) was already done today. They should rather go on cruises. Possibly by 2045 there will already be a competent, sensible government again, and the insulation stuff will be as complicated to dispose of as asbestos today (or even more: to deposit interstellar).