Prefab house from 1976 - ready for renovation or demolition?

Since I assume that a) the basement in case of office use (and other heated or heatable rooms used as storage, etc.) is not regularly heated like real living space and b) the floor slab is more or less uninsulated and will remain so, I would thermally separate these rooms in the basement. The thermal envelope leaks at least downwards and that becomes noticeable.

I partly agree with a). Because if a wall heating were realized, continuous heating would make sense due to the inertia. For b) one can counteract for a few euros. If you let the room cool down for a few days, then it will be over with quick heating later by the heat pump. Then an alternative is needed.

I somewhat agree with a). Because if a wall heating were to be implemented, continuous heating would make sense due to the inertia.

Which brings us back to the limited renovation costs or the "small" budget.

For b) you can do countermeasures for a few euros.

See a). You have to redo the entire floor, have only limited build-up height, exceeding that means new doors/too low ceiling height (with ceiling insulation at least "only" the height you restrict and you are very cheap and simple), etc.

Of course, everything can be done. But it all costs. And the budget is already limited, as quite a bit needs to be done in the actual living area.

I partly agree with a). Because if a wall heating were to be implemented, continuous heating would make sense due to the thermal inertia.

With b), you can counteract it for a few euros.

If you let the room cool down for a few days, then a later heat pump will no longer be able to heat up quickly. Then an alternative is needed.

I partly agree with a). Because if a wall heating were to be implemented, continuous heating would make sense due to the thermal inertia.

With b), you can counteract it for a few euros.

If you let the room cool down for a few days, then a later heat pump will no longer be able to heat up quickly. Then an alternative is needed.

Thank you all for the lively discussion about my (potential) basement. Now, of course, the question arises for me as to how high the budget would need to be in your opinion to sensibly renovate this as well (at least the two rooms that are probably already going to be heated regularly or continuously, but which have also so far been used as normal rooms, i.e. an office and a bedroom). Unfortunately, the realtor could not tell me if there is any kind of insulation hidden behind the wood paneling in the three mentioned heated rooms.

That 300,000 EUR is now considered a small budget does worry me somewhat. Priority, of course, is given to windows, floors (underfloor heating), insulation, piping (electrical as well as water), and heating optimization. Thanks to services from acquaintances, the bathrooms could be kept cheaper. Since the basements are relevant as office rooms, however, a more or less good renovation of at least these rooms would still be a goal of the entire operation.

That 300,000 EUR is now being referred to as a small budget still worries me a bit.

No. That was not meant that way.
But if you already want/have to do essential things...

- 40k windows
- 5k front door
- 3k insulation of upper floor ceiling
- 3k radiators
- 30k heat pump with accessories
- 30k floors
- 30k painting
- 30k new electrical system
- 40k new bathrooms

and these may be more expensive or sometimes cheaper and sometimes more expensive, then you shouldn’t get lost in basement office rooms. Just imagine you have bought the house, and when implementing the measures it turns out that maybe the roof has to be done after all. Or there are new interior doors. Or the lady of the house might prefer underfloor heating instead of the old radiators. Or you suddenly want to optimize the floor plan again. Or the country house floorboards are simply a “must have.”
Then the 300k shrink much faster than you think. Therefore, it’s better to calculate with costs of 250-270k and plan these amounts so that in the end there remains a usual buffer for unforeseen expenses.

From practical experience with commercial real estate clients: We calculate at least 10% buffer for construction cost increases into every construction project (based on construction costs). Additionally, the investor usually has to provide another guarantee for the assumption of an additional 10%. So in total 20%, which we as a bank want to have secured. Why? Because somehow something always does not go as planned in the project.

For a full renovation, I would have told you to plan half a million for the house. Just so you have a feeling of how “small” your budget is – but you don’t want and don’t have to do everything. You just have to set priorities.

What all of this costs in detail is a question of how much talent, time, and perseverance you have. Because a wall heating system on the interior insulation that still needs to be installed can be realized relatively easily as a DIY project. It costs material, but above all, time and effort.

Away from the basement: as I said, I would anyway go in the direction of underfloor heating. If everything is going to be removed anyway, you can usually have it milled in. I would probably make a list of "must-haves" and then go down in priority. Then get quotes for the things you cannot do yourself. Then gather material from the internet for the things you can do. That way you get an overview and a feeling for it.

Here and there additional supervisory work is needed. You must not lose sight of that. If you hire plumbing and tiling separately, for example, you need to clarify when the bathtub will be installed so that tiling can be done around it.

By the way, everyone often has an opinion on individual details. The best example is right here. However, you can free yourself from that, listen to opinions, and then implement your own idea.

Here is an example: a friend of mine has realized this path with the milled-in underfloor heating. He brushed off my suggestion of a wall heating in the bathroom, saying it was too "fancy" for him. He simply installed a classic chicken ladder as a radiator. And he still lives there. So: gather opinions and then follow your own path. Some things will not be "optimal," but will still work.