Is purchasing a house and complete renovation affordable?

... it was 5400 net and currently there is a savings rate of 2700 euros and already 200,000 euros saved up.

350,000 euros purchase price, 250,000 euros renovation needs (I would work that out with a priority list), 50,000 reserve, notary, but NO real estate transfer tax and NO broker, since it’s grandma’s house, so no expenses in that area
==> 650,000 euros ==> 450,000 euros loan.

In the mortgage calculator, I played a bit with the equity because it automatically also calculates the real estate transfer tax.

The rate would therefore be 2257 euros plus additional housing costs.

In reserve there would still be the parents’ 30,000 ... could increase the renovation pot to 280,000.

Whoever managed to save 200,000 euros by 28 should also be able to afford the rate. You just have to plan the children and parental leave carefully, but by then maybe there will also be salary increases.

I don’t see it that negatively across the board.

Then I might have mixed up the threads. Somehow I had 4k net in mind. The savings rate is really good, of course.
You can bridge parental leave, but a year is really long. So you shouldn’t be running at a loss even in those months.
We are currently in that situation. House already in repayment, I’m on parental leave. It’s tighter than usual, savings rates are smaller, etc. But we still manage to end the month in the black. You can’t perfectly time parental leave either.
Going back to work after a year only works if you get the right daycare spot. That was in the media a lot recently, that although you have a legal right to it, it doesn’t help if there are no caregivers.

That would be the point that would still discourage me a bit as someone who is not very risk-tolerant.

I don't see it as universally negative.

I see it similarly. But I'm also somewhat optimistic. As a civil servant, you don't really have to worry about losing your job or anything like that, and although the increases aren't huge, it's somewhat more predictable than the open market. And I think it's commendable, first of all, that the house is being bought, but ultimately the purchase price stays somewhere within the family (of course, it could also possibly go towards the alternative apartment or care, but I can also imagine that Grandma would be happy if the house is spruced up and then maybe some small amount flows back here or there if things get really tight) I wouldn't count on that now, but it does feel different than if the money simply "went away" to some stranger. An old building wouldn't be for me personally, for reasons that have already been extensively discussed here, and I would definitely take the points raised to heart (especially not overestimating one's own contributions). But I don't see it as "impossible." Our alternative is actually the new townhouse on a narrow lot in the neighboring town to our desired city - but I also understand if that's not for everyone.

Yes, of course you can do that. Then there will be no buffer left for reserves and other types of retirement provisions. If I also include [Hausgeld], insurance, retirement provisions, and cars in the calculation, it no longer looks so good.

Well, additional costs, cars have worked so far ... with a savings rate of 2700 euros.

EDIT: What I would still do is get detailed renovation offers.

I somehow had 4k net in mind.

I think someone calculated the 4k net for parental leave. Of course, a >2000€ installment is absolutely no fun. On the other hand, it will pass again.

I am a big fan of thinking in variants.
Variant 1 is the renovated single-family house from Grandma for 2200-2300€. With that budget for renovation, it is certainly up to new-build standards and unwelcome surprises are factored in. Additional costs are then cheap, 130 sqm plus cellar are more than enough for a family. The garden is already finished and not postponed to "later" due to lack of money.
Variant 2 is the new-build single-family house or semi-detached house for >3000€ installment. No need to discuss further, it’s too expensive.
Variant 3 is an existing house from the free market. Newer ones are certainly way too expensive, older ones need renovation. Unwelcome surprises and hidden problems are not excluded. Grandma’s little house is certainly better here.
Variant 4 is the new-build condominium. Probably at least as expensive as variant 1, but definitely smaller. No garden, privacy with question marks.
Variant 5 is a condominium from the existing stock. Cheaper than variant 4, but with the prospect of special assessments in the future. Otherwise like 4.
Variant 6 is renting, I’ll simply take 1500€ for 100 sqm, but that is certainly existing stock and not new build. Corresponding additional costs, plus foreseeable modernization charges. Additionally, the usual rent increases. Cost parity with variant 1 will probably be reached well under 10 years, but then you own nothing at the place, have less space, and no garden.

Anyone with further variants is welcome to add them.

A savings rate of that amount is not rocket science either if you don't pay rent. Then, ultimately, 2700 euros are spent per month by two people. Which is not really thrifty. I'm just playing devil's advocate here, simply to sharpen the view of the real challenges instead of being driven only by fear of missing out and an alleged once-in-a-lifetime opportunity.