Is purchasing a house and complete renovation affordable?

Does that roughly mean, in reverse, that you shouldn't even build under 160 sqm of living space for four people? :)

I almost think that was meant ironically..

We are currently renovating as well, 190 sqm of living space - new electrical and plumbing installed, windows are in - still missing roof + painting + flooring, but we already have quotes for those.

Everything is new except external insulation + basement, for the roof only new covering and insulation, but no new roof structure. In the end, we will probably land at 400k, including photovoltaics and kitchen, excluding exterior works.
From that, about 50k is funding (BAFA + local from the city) and another 15k through taxes.

Biggest cost items:
Roof + photovoltaics = 75k (our roof is still quite small, only about 80 sqm floor area)
Heating + new pipes + bathroom installation = 85k
Painting work (new plastering + painting + exterior painting + designing facade) and floor refinishing = 50k
Architect fees = 35k
Windows + front door + window sills = 35k
Structural engineering + floor plan changes = 35k
Electrical work: 25k
Kitchen: 18k

The rest is small stuff.

The original cost estimate from the architect was 280k - but that didn’t include photovoltaics, a new roof, or facade work.

I would guess we could have saved 30-40k overall with simpler variants (cheap countertop/appliances in the kitchen, no Cat7 in all rooms, no server cabinet, no new interior doors, plastic windows instead of wood, ...) and another 30k for a simpler roof option with insulation at the top floor ceiling instead of a complete new roof. But then we would have had to redo the roof in 10 or 15 years and paid twice.

I can also only confirm that you really have to have the leisure for DIY. Last week I filled in the electrical chases/plaster damage. That was really fun for 2 rooms. But after that I really didn’t feel like doing more. Removing wallpaper was even worse in terms of motivation. When you spend forever on a wall with 5 layers of wallpaper and see no progress, the fun really disappears quickly. I’m glad we didn’t set ourselves too much, but we also have 2 small children :)

For me it would be a problem. And for many others too. You will just have to accept that.

One can also simply choose to say nothing. At the end of the day, you only gave your two cents and gained nothing, but you may have hurt the other person because you generalized and judged their life choices. However, to do that, one would of course have to be able to empathize with other life realities.

Something about thinking outside the box...

The right size is probably somewhere in the middle. Three people on 250sqm is just as extreme as five people on 80sqm. And then it’s also a question of priorities. I don’t need a 15sqm bathroom, but in the living room I want to still be able to move around properly when the Duplo train is set up (and Dad sees it as a challenge to assemble all the parts ;) ) Sometimes it’s the little things that make a house feel cramped or not. For example, the question of where to park the stroller. Is it standing in the middle of the hallway or can it be pushed under the stairs?

Aren't reserves meant for that? *pondering*

They definitely are. Without a relief in energy prices, however, things would slowly look bleak for some. I don't even want to imagine how that has affected people who proudly bought huge properties from the stock two or three years ago with the firm intention of renovating them during ongoing operation.

We are currently renovating as well, 190 sqm living space – new electrical and plumbing installed, windows are in – still missing roof + painter + floors, but we already have quotes for those.

Everything is new except exterior insulation + basement, for the roof only new covering and insulation, but no new roof structure. In the end, we'll probably land around 400k, including photovoltaics and kitchen, excluding exterior works.
About 50k funding (BAFA + local from the city) and another approx. 15k through the tax deduction apply.

Biggest cost items:
Roof + photovoltaics = 75k (our roof is quite small, only about 80 sqm base area)
Heating + new piping + bathroom installation = 85k
Painting work (all new plastering + painting + exterior painting + designing facade) and floor refurbishment = 50k
Architect services = 35k
Windows + front door + window sills = 35k
Statics + floor plan changes = 35k
Electricity: 25k
Kitchen: 18k

The rest is minor stuff.

The original cost estimate from the architect was 280k – but that didn’t include photovoltaics, a new roof, or facade work.

I would guess we could have saved about 30-40k overall with simpler variants (cheap countertop/devices in the kitchen, no Cat7 in all rooms, no server cabinet, no new interior doors, plastic windows instead of wood, ...) and another 30k for a simple roof variant with insulation of the top floor ceiling instead of a completely new roof. But then we would have had to redo the roof in 10 or 15 years and paid twice.

I can also confirm that you really have to have the patience for doing it yourself. Last week I filled electrical chases/ plaster damage. That was really fun for 2 rooms. But after that, I really didn’t feel like it anymore. Removing wallpaper was even worse motivation-wise. If you spend ages on a wall with 5 layers of wallpaper and see no progress, the fun really goes away quickly. I’m glad we didn’t impose too much on ourselves, but we also have 2 small children :)

Those are good figures. We ourselves are currently renovating my parents’ house. Living space 230 sqm, location NRW. For the house, I took out a loan of 150k from KFW and get a repayment bonus of 35%. The total budget is 550k without exterior works, but with many amenities. Except for the foundation walls, everything is being done "new." We have no craftsmanship skills and did the demolition ourselves. Please don’t underestimate the costs for disposal :-) . We have experience from several new builds that we have accompanied as "construction managers." Good friends of ours are taking over construction supervision and are competent. The selected companies are well-known in the village and do good work.

Otherwise, roughly the trades:
15k disposal/demolition
5k earthworks
75k for shell construction work, widening foundation, brickwork, insulating house walls, sealing basement, installing new inner windows, partially inserting beams, and a concrete staircase
18k for new bricks
40k roofing work
80k carpentry work, one floor completely timber frame construction
80k plumbing, 2 bathrooms, 1 guest WC, all piping new, air-to-water heat pump, central ventilation system, underfloor heating
40k electrical, partly smart home for ground floor, all new wiring
10k interior plaster, partially necessary on the ground floor
20k tiling work
10k interior doors, including loft door
17k flooring
6k screed
48k windows, expensive aluminum exterior door, south side fully with external blinds
10k drywall
20k photovoltaic system
32k kitchen
14k sauna
6k ancillary costs for structural engineer, architect, and energy consultant (all friendly colleagues)

Fingers crossed for you.