Can we afford this?

Hello,
we had a consultation today at Bien-Zenker, as we have the desire to buy a house. However, we do not know if this is currently feasible.
A brief overview of our situation: my partner is 27 years old and a childcare worker earning €1580 net per month, and she is currently protected from dismissal because she is 50% physically disabled. I am 26 years old and a civil servant (from 01.02.2011 I am a lifetime civil servant) and earn €1680 per month without allowances.
We are also planning to have children in the next few years, but it can still take about 3 years.
We also have a plot of land in sight which is 352m² large and costs €88,000 including development costs.
We would like the house to have a basement (but we need a "white bathtub"). The house (Efficiency House 70) was calculated with a basement (white bathtub) and the associated equipment including our own efforts and estimated material costs. In the end, we come to €185,000, and we were told that we should expect about €30,000 in additional construction incidentals. When I add everything together, we come to €303,000.
Now our question is whether it is realistic to calculate with the additional construction costs? And do you think it is financially feasible?
We have about €27,000 in equity, which would be available immediately.
We would be very grateful for your help.

Hello, the house is to be about 130m² in size. Included in the price are the earthworks, gas condensing boiler, and the water treatment on the roof. The house is technically finished so far, so we still have to do the floor coverings and the wall work (puttying and wallpapering). The amount of €10,000 was also mentioned to us, but this was accepted as it is listed as working material of the company Bien-Zenker when they do it themselves. The notary/land registry fees have already been included in the land price by us. Therefore, these do not have to be considered anymore. We were at Bien-Zenker in Darmstadt and actually found the conversation very, very informative and friendly.

Hello, does none of you have a tip for us whether this could fit or not? And possibly how we should change the numbers???

Good morning,
at that price I would have it done immediately, of course it also depends on what kind of materials are used.
I can hardly believe that they do it for that money including tiles???
Regards

The €10,000 only includes the material, which is based on cost statements from Bien-Zenker. If you don’t lay the tiles yourself, then of course the tiler’s costs are added on top.

Hello, yes, we have also thought about that, as this will also happen. It will also be fine if you only receive 67% of the salary.