Is the construction project affordable? 570 k€ loan with a 5300 € salary

Hello everyone,
we are planning to buy a house and would like to ask for your assessments.
It is a new single-family house built to KFW 55 standard with 150 sqm living space + basement with air-water heat pump and photovoltaic system with storage in Bavaria.

[*]How old are you? 32, 32
[*]Do you have children? Not yet
[*]Are children planned? Yes, planned
[*]What do you do professionally? employed engineer, employee in the public sector
[*]How many hours do you work? currently 35, 39

Income and asset situation:

[*]What incomes do you have? Net (3300 + 2000) total 5300 €
[*]How much equity do you have? 180 k€
[*]How much equity do you want to invest in the house project? 120 k€ financing + 30 k€ (kitchen, …); 30 k€ are reserves

Housing costs:

[*]current warm rent: 700 €
[*]electricity: 35 €

Mobility: 1 car with 300 €

Living expenses:
Groceries, GEZ, cats, gifts, hardware store, internet, mobile phone, personal liability insurance, clothing, beauty, canteen food, restaurant: 1530 €
Retirement provision: 2*150 = 300 €

Future house expenses: (photovoltaic electricity generation not included)
Insurances (household, building), property tax, water, sewage, electricity, waste disposal, term life insurance: 490 €
Maintenance reserves: 1 €/sqm *150 = 150 €

Total income: 5300 €
Total expenses (without warm rent): 2130 + 640 = 2770 €
Balance: 2530 €
General information about the property:

[*]How large is the plot?: 315 sqm
[*]New build, single-family house
[*]Double carport
[*]How large is the house?: 150 sqm living space, 50 sqm basement

Construction or purchase costs:

[*]Purchase costs (construction costs house ready to move in, plot, development costs, ancillary construction costs, outdoor facilities, photovoltaic + storage): 618 k€
[*]planned optional services and special requests: 37 k€
[*]additional acquisition costs (notary 2%, land transfer tax 3.5%): 36 k€
[*]Total costs: 691 k€

Cost breakdown:

[*]Total costs: 691 k€
[*]deductible equity: 120 k€
[*]financing amount: 571 k€ (without considering KfW55 repayment grant of 18 k€)

We are currently planning a monthly rate of 1800 €. This would leave a monthly surplus of 730 €.

What is your opinion on our planning? Are we overextending ourselves?
Have we overlooked costs? Are the assumed expenses, incidental costs realistic?
How does it look with children? What additional monthly expenses should be planned for a child?

First of all, where is the catch, the house is way too cheap. Or no garage and garden included?

Income is not substantial for such a high loan amount.

Hello in the forum!

Is this a tied selling with a developer? Are those really all costs or just "catalog/advertisement prices" for now?
If the price is final like this, including all groundworks etc., then it is very good. (Where exactly in Bavaria is the house located?)

Otherwise, regarding finances: Thanks to the equity, I see quite good possibilities, although at the upper limit of what is feasible. We have comparable net income without significant equity and finance 515k with a 1,500€ installment. However, our children are already there, so we know our minimum income. Be aware that as soon as children come, the wallet will be squeezed a lot. And this period can last anywhere from 12 to 72 months.

On the whole, that seems coherent and feasible to me. I can't assess whether the costs for Bavaria are realistic. With a basement, it seems inexpensive to me, but if you are sure that you can make it with the budget, then it should be doable with your income. How much offspring is planned? For the first child, you can often get by relatively well with the 65% + maternity leave periods with full income. If you can return to work after the first 1.5 years, it works. Am I correct in assuming that it is the income of 2k that partially disappears with offspring, not the income of 3.3k?

We have just built under similar conditions. Slightly less income, slightly less loan amount. One child, house financing during my parental leave. Meanwhile, I am working part-time again, as planned. We knew that the first 2 years would have to run with a tighter belt since the new (higher) burden from the annuity coincides here with my part-time income AND the daycare fees. When the little one turns 3, the daycare fees disappear, then it becomes more relaxed again.

So far, financially it is going as planned, even a little better. A second child is not planned for us. If we were to change our minds spontaneously, that would still be financially manageable, but then the long-distance trips would move further into the future. ;)

Are the assumed expenses, additional costs realistic?

To me, it reads quite solid. The additional costs will probably be somewhat lower, and a reserve fund is not necessary in the first few years, but overestimated money can always be allocated somewhere ;) The only thing to consider would be the months/years with the first/second child. Free or inexpensive childcare would be nice there so that the woman can go back to earning. Car savings rate for a new one? How does that look?

Purchase costs (construction costs house ready to move in, land, development costs, ancillary construction costs, outdoor facilities, photovoltaic + storage): €618k

Such offers usually lag behind on the items that are ultimately not included in the offer, without seeing them. Do you have an ID for the exposé in a portal that we could quickly check?

planned optional services and special requests: €37k

That’s quite a bit. Keep in mind that the first years are characterized by expenses -> lawn mower, garden furniture, planting, furniture, lamps, etc. But somehow these things work out, as you can invest in them instead of a vacation.

I also find it solid