Financial planning for new construction with good income and little equity

Next, painful tip:
Save as much as possible, completely, for at least 1 year. See how much accumulates. Keep a household budget! Where is the money flowing out?
It seems to me that either the income situation is still relatively "fresh" as it is, or that a standard of living has been maintained so far that would not be sustainable with a house construction under the given conditions. And losses in living standards are enormous stress factors. Please do not underestimate that.

Yes, it is a mix of both factors, on the one hand our income has indeed grown quite significantly in recent years, on the other hand, the standard of living has almost always been adjusted unconsciously. However, we see that additional costs for installments etc. amounting to 1,000-1,200 EUR/month are manageable without major sacrifices, especially since my salary is expected to grow by about 10% at the beginning of 2025.
Now to an update: I have received a cost breakdown from the franchisee of Town & Country, which is the topic here. Well, what can I say – most people here were right. The financing requirement was set at 405,000 EUR. Topic real estate transfer tax for the house: set at 0%, with a note that you should consult your tax advisor here because “the legal situation is not uniform.”
So mentally here +20-25k EUR. House connection costs – estimated at 10,000 EUR for everything. Call to the municipality, with reference to the specific plot, statement: water connections alone minimum 20,000 EUR. No buffer for upgrades, other cost items may also be understated...
At half a million you really end up there quickly. So that topic is off the table, politely declined.

Now a new game. We are currently looking one level cheaper – terraced house / semi-detached house. In Rhineland-Palatinate, between Mainz and Alzey, I came across an interesting project. Semi-detached house, 140m2, ALL IN (allegedly): land, house, outdoor facilities (down to roll lawn and fence), garage + parking space, floors and wallpaper, photovoltaics, tiles, bathroom equipment (Grohe and co), KFW40, and so on. In other words, you get the keys and move in. Cost point: 456,000 EUR + incidental purchase costs 7%.
We have meanwhile reviewed and think we have a way to cover the incidental purchase costs, which here would be about 30k EUR, without it hurting.
Thus, 100% real estate financing, first assessment by the financial advisor: 3.56-3.8% loan + 3.11% KFW loan 100,000 EUR = under 2,000 EUR monthly repayment.
What does the esteemed community of the forum say? The construction service description apparently also includes all “classics” at first glance – of course, both the construction service description and the building energy law contract will be reviewed in advance by experts. If no gaps/traps are detected anywhere and we definitely see that no upgrades are necessary = I think we can afford this. But as said, only if one has sufficient assurance that no further costs can arise (force majeure like insolvency etc. excepted).

Thank you!

Do you like the floor plan? Because there usually won't be any major redesigns or only for a hefty additional fee.

Do you like the floor plan? Because major redesigns will usually not be possible or only for a hefty surcharge.

I'd say it has 95% of what we want. We'll look at the remaining 5%; if it's not possible or too expensive, we can live without it.

Then please post the ID of the portal here from the exposé to check the offer for hidden costs. I think it is positive that you asked Town & Country right away. Do you already have an appointment at your house bank to roughly discuss the possibilities (limit)?

Then please provide the ID of the portal here (no link) from the exposé, to check the offer regarding hidden costs. I find it positive that you inquired with Town & Country right away. Do you already have an appointment with your house bank to roughly discuss the possibilities (limit)?

House bank (+ financing advisor), yes there have been talks and official offers, 450,000-470,000 EUR is feasible. Regarding the ID of the portal, I am clueless, what does that mean? I simply received a PDF of the construction service description and a price list by email. It is no longer about Town & Country house, this is an offer for semi-detached houses in RP. Local project developer who has applied for a general contractor whose name I do not yet know but will find out.

Local project developer who applies for a general contractor whose name I do not yet know but will find out.

You don't have to care about the general contractor. They are not your contracting party. Your house construction owes you a house – how they build it is a business decision. Maybe everything will still change after signing the contract. You cannot influence that.