Partial renovation of terraced house financial framework

Hi guys,
hope I’m not annoying you with another title like “please roughly estimate my costs.” I’ll try anyway because none of the threads really fit our case.

We have the opportunity to buy a house in the desired location and size. We originally planned to buy a house or start actively searching in 2-3 years, but sometimes opportunities come up unexpectedly. The property, location, and price basically fit perfectly, except for the annoying renovation issue.

About the house:
-row house in the middle
-built in 1978
-75 sqm plot
-110 sqm living space—>ground floor 55 sqm, 1st floor 55 sqm
-attic not developed
-basement
-28-year-old oil heating system

We already got a firm offer from the seller, just need to give our go-ahead.
We spontaneously got the key for a few days and were able to show it to a few experts who know about the subject but unfortunately not all trades and the energy consultant, as no appointment was available so quickly.
Of course, we would prefer to have a detailed renovation plan, but that’s not possible for time reasons.

So here’s our plan:

-old heating out, new heating heat pump in
-underfloor heating ground floor and 1st floor
-corresponding screed out and back in
-new windows (6x standard, 1x large window with sliding door approx. 3.5x2m living area) + roller shutter boxes KV is currently being written
-probably necessary decentralized ventilation
-walkable attic insulation
-basement ceiling insulation
-new electrical system KV is currently being written
-new water pipes
-new kitchen
-1 bathroom (9 sqm) 1st floor new
-1 guest WC new
-new flooring
-plaster walls, wallpaper on top
-stairs can stay
-interior doors can stay
-roof in very good condition, no measures necessary
-basement dry, no measures necessary
-floor covering installed
-no changes to room layout

Basically, we have no big demands on kitchen, bathroom equipment, flooring, etc. We just want to have a good energetic and renovation technical basis and things that need to be done and make sense in the course of an initial renovation. Things like photovoltaic system and external insulation, depending on budget, new front door, which are basically useful, can, in our opinion, still be done in a few years without us having to move out temporarily. So we see the house more as a long-term project.

I am also handy myself and enjoy putting my own work into projects, but I’m not a professional, so I can imagine doing simple DIY work in the house but I clearly know my limits. That means things like gutting, basement ceiling insulation, attic insulation, wallpapering, painting, and whatever else comes up I would do myself. My idea is that, without much time pressure, I would gladly do things like new basement tiling or changing interior doors myself in the following years.

I find it really difficult to estimate the renovation finances here because it’s neither a pure renovation nor a complete overhaul. A friend who is an architect, but only has limited knowledge in this area, said he would calculate with €200,000, but probably less. Of course, I have already done a lot of research myself, but I don't have much confidence in Dr. Google, and most threads from recent years simply don’t really fit our project.

What do you think, does this plan even make sense and are the renovation costs realistic?

Morning! First of all, this is not a partial renovation, but a complete renovation. I would actually also replace the interior doors. That way, there are no problems with the heights and those would be the only "old Schrömmelken" left inside. Before I reached the end of your post, my gut feeling about the measures and the size of the house told me: It should cost around €200,000 – so about €2,000/sqm. The shell including the roof remains, the rest is new. Although for the €200,000 I would actually also budget an ETICS. My tip: Go all out and make the house a KfW 55 house. It might cost a bit more gross, but after funding, in the end significantly under €200,000. Then the heat pump also pays off, because your heating costs will probably only be around €30 per month.

What do you think, does this plan make any sense at all and are the renovation costs realistic?

Your plan sounds reasonable, I cannot provide any information about costs. Take a look at this thread with a link to another similar project (changing tires while driving by ): A terraced house from 1978 sounds to me spontaneously like: an insulation upgrade of the exterior walls might have to be done from the inside; and: presumably already completed modernization measures in the same settlement or even row of houses.

Thank you already for your answers. The problem with the exterior wall insulation is that it is a slightly offset terraced house, so the insulation would extend into the neighbor's front yard + no gable projection. Unfortunately, on this side the staircase is in the way for the interior insulation, which we do not want to touch as it would probably exceed our budget.

The problem with the external wall insulation is that it is a slightly offset terraced house in the middle, so the insulation would extend into the neighbor's front garden

That is initially not a problem. At least not in almost all federal states it is not your problem.

no gable condition.

Stupid. You would have to calculate financially. Additional effort compared to the subsidy.

The problem with the exterior wall insulation is that it is a slightly offset mid-terrace house, so the insulation would extend into the neighbor's front garden + @11ant no gable overhang. Unfortunately, on this side, the staircase is in the way for interior insulation, which we do not want to touch as it would probably exceed our budget.

Whatever relevance this now has to the fact that there is no gable-side roof overhang; indeed, that is an additional complication here. The neighbor could quite reasonably be expected to tolerate a build-over of his property with insulation. I see the staircase here rightly identified as an obstacle for interior insulation. Moving it – as far as technically possible – would be economically unreasonable. However, considering the 24 cm thick exterior walls (unless they are aerated concrete), insulation is already advisable here – I had expected 30 cm pumice hollow blocks or porous bricks given the year of construction. Overall, I therefore recommend refraining from this.