Purchase decision small semi-detached house 100 sqm from 1930

We also have "only" 102 sqm and there are three of us. The house was built in 1930 and a family of 13 people moved in....and I don't think the extension existed back then.

35k EUR for the HVAC with two new bathrooms plus heating (new system, underfloor heating) is far too little. Starting from 50k EUR upwards. Don’t forget the architect. And if the roof is going to be redone anyway: add a photovoltaic system at the same time, possibly even integrated into the roof (instead of the roofing membrane). You don’t want to insulate the facade?

Okay, then I’ll plan that item a bit more generously. However, I’m still not quite sure if a heat pump will even work for us. Honestly, I have no idea where the outdoor unit could be installed on our property. All routes to the boiler room are quite long. Facade insulation is not planned for now, except for the two dormers, because they need to be newly slated anyway (I have now factored that into the roof). Such facade insulation with all the associated work is really extremely expensive. I hope that with new windows, a new roof, insulation of the dormers, and basement ceiling insulation, we’ll be doing well for now. We don’t need an architect. We’re contributing quite a lot of electrical work ourselves and have enough contacts with craftsmen. Photovoltaics are budgeted at 20k € – it’s included as such.

Topic heating: Does it make sense to initially continue operating the heating with low-temperature radiators and surface heating in connection with the oil heating system, then with a lower flow temperature - and later simply replace the oil heating system with a heat pump? Or in other words, is that even possible?

Currently, it is difficult to get a heat pump at all. The idea would then be to simply replace the oil heating system later when the market has calmed down again.

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We don’t need an architect. We are contributing quite a few electricians and have sufficient contacts with tradespeople.

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Think it over again. The term architect might not be quite appropriate here; it’s more about construction management and coordination of the trades. Schäfer definitely has no experience. A pragmatic civil engineer, possibly.
Additionally, a competent energy consultant, depending on subsidies and/or also just for various calculations.

Both cost money but are well invested.

Think it over again. The term architect might not be that appropriate here, it's more about construction management and coordination of the trades. Schäfer definitely has no experience. A pragmatic civil engineer maybe.
Additionally, an energy consultant who is competent, depending on grants and/or also just because of various calculations.

Both cost money, but it’s well invested.

We will reflect again ;) Basically, no one is rushing us and we have time. If there is some standstill in between, the world will not end. Provision interest or even repayment alongside the current rent would be annoying, but manageable. We currently live rather cheaply with 500 € cold rent.

An energy consultant should definitely come. It doesn’t cost a fortune and in my opinion, it’s simply a must nowadays.

Hi and thanks for your post :) Can I find your renovation project somewhere here? Do you have a link for me? Best regards Any other feedback on my cost breakdown? :)

So, now I can write extensively from my laptop. I never presented our project separately here, but I’m happy to write something about it now. Our house was also built for mine workers, in 1921. The plot is larger though, about 650m2, because feed for the pigs, which lived in the basement stable, was grown here. Our house was fitted with bathrooms in the 60s (before that there was a laundry room in the basement). In the early 90s, the roof, facade, windows, and exterior doors were renewed. We bought it in 2017 and renewed the following: electrical system, roof insulation from the inside to create living space under the roof including a new small bathroom there, roof windows, most other windows, bathrooms, water pipes, floor coverings, interior doors, stairs uncovered, sanded and glazed, paneling removed and ceilings dropped with drywall to 2.60m. Over the last 5 years, we renewed the interior plaster on the first floor, plastered the basement inside with renovation plaster and handled lots of small jobs and dug up a lot in the garden. Next year, if all goes well, we will renew the interior plaster on the ground floor (it’s now 101 years old!), insulate toward the basement (so far uninsulated wooden beam ceiling over vaulted basement, feet cold in cold winters), renew the last 3 old windows as well as the front door and, depending on costs, install underfloor heating, heat pump and photovoltaics. Our gas heating is from 2010 and runs perfectly so far, but I think I don’t need to mention why we want to switch before it breaks down on its own. What did we spend on it? We took out a €39,000 loan for the renovation, which we used up. With a mix of craftsmen and own work, we have since reached estimated renovation costs of €50,000, could be more, unfortunately I didn’t list it separately and we just kept going when money was available. Mind you, quite a bit of own work, no frills (simple electrical, cheap doors, laminate) and prices from 2017.