Is the construction project feasible or are we taking on more than we can handle?

We could finance the plot without a loan, as a parent would provide an interest-free loan here.

Even an interest-free loan is a loan. I gather that you also have to pay it back, the money is just "advanced"?!
Personally, I actually recommend a private contract for something like this, so that the money is secured for the parents in case of a breakup.

The plots are intended for bungalows, which is also what we want.

Hmm, I don’t quite believe that. The term bungalow doesn’t really exist. I assume a single-story construction, which for example also includes a normal gable roof house with two living levels. The 1 refers to one full floor.

Equipment as always not just standard, but also no luxury. Underfloor heating is desired. List prices, for example at Town & Country, are around €220,000

But I wouldn’t go with Town & Country. This house builder is rather a cheap option. With too many change requests and upgrades, there is a lot of potential for trouble, dissatisfaction, and construction defects.

Furniture, outdoor facilities and prefabricated garage would then be added.

Also the ancillary construction costs and painting work…

€220,000 house
€40,000 upgrades (you have to see what must also be paid extra in terms of technology and energy efficiency. The Eco-55 variant is already a special feature… it doesn’t come for just €3,000)
€20,000 painting work and floor coverings
€25,000 outdoor facilities
€15,000 prefabricated garage
€30,000–50,000 ancillary construction costs

plus plot.

Thank you for the answers.
That sounds very sobering. I have now read it as meaning that below 500k it will be quite difficult, maybe even unrealistic. We were hoping more for 400-max. 450k
up to 1800€ monthly (1500€ installment) credit including incidental costs I would already consider feasible for us. But I would probably get a loan of around 330,000€.
As already mentioned, with regard to family planning, our salary is rather unlikely to be maintained, so I would calculate with 4500€ instead.
We could now speculate and secure the plot and see how everything develops in 2-3 years. The risk of losing the costs would still be quite manageable. (Notary, land registry and real estate transfer tax as costs (approx. 5-6000€).

Thank you for the answers. That sounds very sobering. I have now read it as meaning that under 500k it will be quite difficult, maybe even unrealistic. We had rather hoped for 400 - max. 450k. I would already consider a credit of up to €1800 monthly (rate €1500) including additional costs. But I will probably get a credit of only around €330,000. As already mentioned, with regard to family planning, our income will probably not be maintained, so I would rather calculate with €4500. We could now speculate and secure the plot of land and see how the whole thing will develop in 2-3 years. The risk of losing the costs would still be quite manageable. (Notary, land register and real estate transfer tax costs (approx. €5-6000).

Add the rate for the family (land) on top of that. So about €400-500 monthly extra. With 2% repayment and €400,000 financing (€470,000 costs - €70,000 equity) at 3% interest, you would then be at: €1666.67 + €400 (family) = €2,066.67 + €300 additional costs = almost €2,400. That is already very borderline.

The plan was rather to pay back the €40,000 in 3 years and then start building.
Land purchase would presumably be 01/23.

Thank you for the answers. That sounds very sobering. I have read it as meaning that under 500k it will be quite difficult, maybe even unrealistic. We were hoping more for 400 to max. 450k. Up to 1800€ monthly (1500€ installment) credit with additional costs I would already trust ourselves with. But I would probably get a loan of only about 330,000€. As already mentioned, with regard to family planning, our income probably won’t be maintained, so I would rather calculate with 4500€. We could now speculate and secure the land and see how things develop in 2-3 years. The risk of losing the costs would still be quite manageable. (Notary, land registry and real estate transfer tax as costs (approx. 5-6000€).

I think it is possible. Last year we built a bungalow with 107 sqm for 230,000 euros, with a small regional company. With heat pump, underfloor heating, electric shutters, a large sliding window. Additional building costs maybe 20,000 to 30,000 euros, I would have to calculate that. It largely depends on what the connections cost in your area, there is a wide range. But you can find that out from the utility providers. However, we did the painting and flooring ourselves, for that you don’t need 20,000 euros, maybe 5,000. We also did the exterior work completely ourselves. Although we have been living on the property for several years, so there was already a garden, driveway and garages, but we had also done that ourselves once. You don’t necessarily need a garage, you can also build one later. Plants and stones can be obtained through classified ads, if you want. And maybe you can contribute even more self-performance, do the insulation yourself, chases for the electrician, drywall. But that certainly works better with smaller regional companies.

Hello, if the 450-500k come as construction costs, plus one child and part-time work, it is unrealistic