Cost estimate for renovating a 1970s semi-detached house according to KfW or BAFA

P.S.

Due to your geographical location, please buy your insulation in Nettetal. For example, PUR/PIR with fleece for basement wall insulation at half price.

Why insulate between the rafters when the top floor ceiling is supposed to be insulated?

If you look at the sections, the roof is finished, just not completely open all the way to the top, but rather a ceiling is suspended or something like that. I think this is what is meant here by "top floor ceiling." "Just insulate the top floor ceiling" doesn't make sense because the ceiling between the upper floor and attic wasn't meant here, but only the very top part... (I'm not a renovator, whether in practice you would actually remove the ceiling in the attic and insulate the roof up to the peak and then maybe suspend the ceiling again or not, I don't know exactly. - that would rather have been my idea, but maybe that is also wrong)

If you look at the cuts, the roof is developed, just not completely open all the way to the top, but a ceiling is suspended or something like that. I think this is what is meant here by "topmost floor ceiling." "Just insulate the topmost floor ceiling" doesn’t make sense here, because it wasn’t meant to be the ceiling between the upper floor and attic, but only the very top bit... (I’m not a renovator, whether one practically takes out the ceiling in the attic and insulates the roof all the way to the peak and maybe then suspends the ceiling again, I don’t know exactly. - that would have been more my idea, but maybe it’s wrong)

I agree. Attic is meant here by insulation of the topmost floor ceiling. But that doesn’t exempt from insulation between rafters in the attic. However, that can be done quite completely in EL if you are motivated. I would also do underfloor heating + heat pump. If you don’t have all that done by a contractor, it can be done for 25-30k€. I would also have windows and facade done. That will cost a bit of money. I would rate the rest as things you could do if you want. Although electrical and plumbing maybe also make sense. In my opinion, if the water pipes are steel, they should be replaced. I would leave copper pipes. Unfortunately, I cannot say anything about any subsidies and personal contribution.

I would also say that some items fit, but others are significantly too expensive (e.g. photovoltaics: normally I would say you should manage with 1500€/kWp -- and I don’t believe you want to or even can install 20 kWp there? Storage usually doesn’t pay off, because it’s dark and often cloudy in winter. We have now generated maybe 200 kWh with 12 kWp in December because the sun just doesn’t shine. That is all consumed immediately (heat pump)).

However, I also believe that you will not manage with 500T€ for house purchase + ancillary costs + renovation (if you do everything or have everything done).

For major renovations, you can actually estimate 2000€/sqm quite well. We spent 1700€/sqm last/this year WITHOUT basement and facade, but including kitchen and terrace.

Does it perhaps make financial sense to split the work and first do the "inside," keeping the old heating system (2018 is still quite new), and then catch up on the "outside" (facade, roof, basement) in a few years? So, would you have enough leeway in the financing to save, or is that already calculated quite tightly? I would possibly also question the 55EE target and see how it would work out with individual measures. You can also spread those over several applications and several years (e.g. 2025 heating + windows (you can also include new pipes, radiators/underfloor heating, parts of the electrical system and consulting/planning costs) – and then for example 2026/27/28 facade/roof). Of course, it’s a risk regarding the constantly changing subsidy conditions. However, there is also the possibility to deduct renovation from taxes. There is always a 20% subsidy for energy measures.

For example, we have:
- 2022 application for individual building envelope measures (still 20% then) --> roof for 60,000€ --> 12,500€ reimbursement
- 2023 heating application (40%) --> 71,000€ costs -> 24,000€ reimbursement (capped at 60,000€)
- 2023 tax return: windows (reimbursement still outstanding)

What I find strange:
Roof insulation between rafters + insulation of the top floor ceiling:
a) I find it MUCH too expensive for the price given the roof size. For that money, we got a complete 170 sqm roof with insulation between rafters AND over-roof insulation AND new tiles AND scaffolding AND old roof demolition (only the roof frame from the old remained), with ecological building materials (there was a small subsidy from the city for that). Your roof is, if I see it correctly, significantly smaller.
b) Accordingly, I would prefer a completely new roof to the proposed solution. For example, we had tiles from the 80s on which the roofer was already worried about anchoring the photovoltaics. If you put photovoltaics on the old tiles now, that could possibly lead to problems in the long term?

Property in the Cologne/Bonn area

Then I'll call you all into the thread, he is an architect with a focus on building renovation, in Münstereifel (indicates vnac as first name last name, then you will find him).

I just wanted to raise a point regarding the topic "can easily be done yourself," that one should be aware of what this might actually mean. If it is scheduled alongside other work, then it’s not going to be very comfortable. If it’s not properly scheduled and things happen one after another, you can quickly end up with a permanent construction site.

Regarding the painting work, I would also like to point out that there is likely more involved than one might initially imagine from the rental apartment (so not just "paint over existing woodchip wallpaper once or twice"). I see the stairwell over 4 floors (I don’t know if I would want to do that) and I also see items like electrical wiring and water pipes on the list, and I wonder whether depending on the current surface there might be more work required (is it enough to fill in the grooves or do you have to remove old wallpaper, possibly re-wallpaper, and only then paint). Parts of it should probably still be done yourself, but I just want to point out that even "something that simple" might involve more effort than the item initially suggests.