Home renovation / Renovating built in 1952

Hello dear forum!
So far I have read a lot and now I have a question for you:

We are planning to buy a small settlement house in the south of Germany (Waldshut-Tiengen).
The house was built in 1952. In 1977 the roof was newly covered and insulated with glass wool at the same time (seller’s statement: no asbestos). In 2011 the roof tiles were coated.
The house is heated with night storage heaters, which are also said to contain no asbestos. The hot water preparation is done by a gas boiler.
The house has a living area of just under 150 sqm. The plot measures 570 sqm.
The house is fully basemented, which does not appear to be damp.
The house itself is very well maintained, but not "up to date" anymore.
The windows were replaced with double-glazed windows in 1999.
I know you can only roughly estimate costs, but maybe someone here already has more experience in this area.

We have planned:

Renewal of the heating system (gas is an option since it is already in the house)
- What do you think the installation costs will be?

Thermal insulation outside, attic and basement ceiling
- A friend who is an architect suggested a rafter insulation because it does not create dirt inside. The attic is one large room that was used as a children's room. We actually wouldn't need the room, so insulating the top floor ceiling would also be possible (+ the sloping ceilings on the upper floor).
- What would you find more sensible, how do you estimate the costs? The roof still looks very good and according to the architect should last another 20 to 30 years.
We would have an ETICS installed on the outside
- What do you think the costs for this will be?

The electrical system was renewed on the ground floor; on the upper floor it is original from the year of construction. The water pipes are all from the year of construction.
I planned to renew all the water pipes and also the electrical system (possibly a BUS system, since it is a men’s toy and a good friend is a master electrician, but not a MUST!)
- Is it sensible to renew the water pipes? (A water softening system is installed)
- What costs should I expect for this?
- For the electrical system I have estimated 15,000 - 20,000 euros

Inside we would like to make some floor plan changes. So it can get dirty.

We have planned to do as little as possible ourselves. However, demolition work and "chasing" the walls can definitely be done by ourselves.

I am very grateful for suggestions, answers and cost estimates! I can of course also gladly answer questions.

Many thanks!

Fabian

Renewal of the heating system: Should radiators be installed or underfloor heating? Then the screed must also be removed. Costs 20-30k

I would seriously consider thermal insulation. The roof is already insulated; if you really don't use the room upstairs, you can add insulation directly on the floor, which is no big deal. DIY for 2k no problem.

Insulating exterior walls is expensive and never pays off. But if you have to / want to do facade work anyway, it can be done. Costs start at 30k.

Insulating the basement ceiling: Is the basement planned outside the heated envelope? That means a correspondingly tight door from the stairwell? Otherwise, you can save yourself that. I can't say the costs, no experience.

Electrical work could in my opinion even become cheaper if you do a lot yourself, although I can't estimate the costs for the BUS system. Pure electrical work with a lot of DIY should be feasible well under 10k.

Water piping definitely completely new, including wastewater. You have to lay heating pipes anyway. Doesn't cost the earth; together with the rough installation of the bathrooms, I would estimate about 8k.

What is missing are the floors and bathrooms. Tiling is not cheap, that adds up quickly. Sanitary fixtures also have huge price ranges; if you buy yourself, it's relatively manageable, but if you go for luxury sanitary ware, it quickly becomes astronomical.

Layout changes: Structural builder or drywall builder necessary, structural engineering must also be considered. What about windows, doors, interior doors?

Basically, we are talking about a core renovation without the roof; roughly, you can calculate 1000€/m².

Thank you for your response!
Sure, underfloor heating would be great, but in my eyes it doesn’t have to be done. We could live well with radiators.

If you think that insulation of the top floor ceiling is sufficient, we would do that, I think the own work shouldn’t be a problem.

Exterior walls never pay off? Since the house was repainted in 2005, nothing needs to be done. I just thought it would bring a huge benefit. Nice if the 30k can be saved!

No, the basement is connected to the living area via the stairwell (a normal door). So insulating the basement ceiling actually doesn’t bring anything here.

For the electrical work, I would like to do the auxiliary tasks, maybe chisel open the wall, etc. Maybe also pull in the cables. A BUS system would be a luxury I would like to have. I’ll just have to see how expensive that would be. But of course I could also do without it.

Water and sewage piping: Perfect, I had also planned this cost framework.

In the bathroom we would shop ourselves and then hand those things to a plumber. We would also buy tiles ourselves and then have them laid.

Regarding floor plan changes: Only two / three walls are to be “removed”. According to the architect, no problem.

The windows are double-glazed thermal windows from 99, which are supposed to still be “great”. We would leave them as is. Maybe widen a door to the conservatory.

The interior doors should all be new, all with frames, just because they’re not to our taste. I have estimated 5,000 for that. For new floors and wall coverings (plaster, painting, etc.) each 10,000.

If those were all the costs, you’d be pretty cheap overall.

If anyone has any comments or tips, I’d be happy!

Thank you for your answer! Of course, underfloor heating would be great, but in my opinion it’s not necessary. We could live well with radiators.

I feel the same way in the "old building" right now, we also stuck with radiators (house built in 1900).

Exterior walls never pay off? Since the house was repainted in 2005, nothing needs to be done. I just thought it would bring a huge benefit. Nice if the 30k can be saved!

Never might not be correct, but if you do it solely to reduce heating costs and not also because the facade needs renovation, then calculate how many years it will take to pay off.

For the bathroom, we would shop ourselves and then hand these things over to a plumber. We would also buy tiles ourselves and then have them installed.

Be careful, this is often not well received and doesn’t necessarily have to be cheaper. If you don't want overly fancy options for the basic stuff, it’s usually more sensible to get it through the plumber. The plumber often adds a markup on the labor for such items, the same can apply to the tiler.

The interior doors should all be new, all with frames, simply because it’s not our taste. I calculated around 5,000.

You can do that well yourself and if you are happy with decent standard doors, then you can calculate about 220-250€ per set of door and frame. Of course, it depends on what you want, whether you need special sizes, and where you buy, for example, we installed Herholz doors and are very satisfied. Installing on your own with some skill is not rocket science.