Feasibility of financing a single-family house approximately 150 m²

It looks tight at first. Feasible but tight. I would add about 50k for house costs. The new salaries are good, before you felt like you sold yourselves short. For better understanding, it would help if you wrote more precisely what kind of properties you have at what value and how much you have already paid off.

Thank you for your and everyone else’s assessments. That also matches my feeling with the children and that it will be tight.
I have only been working full-time again since 2020 after my second degree, so I am still in the entry-level salary range. And with my husband, it is certainly the case that he sold himself short.

I am aware that this is probably too little, but this is where I would most likely make cutbacks and do a lot myself in the coming years.

Don't underestimate that. Outdoor facilities are a battle with materials and you also need the appropriate equipment to process it.
I have calculated €12,000 just for materials and equipment rental for the base, paving (no luxury, rather about €35/sqm), splash guard, trees, lawn, house entrance. Garden shed and carport have their own calculation. Fences are not planned for now and the retaining wall around the terrace either (the slope looked a bit smaller back then ;) )

The €350,000 is initially a rough estimate, our architect said it is feasible. We will have to clarify soon how much earthworks are included once we have concrete costs and a floor plan.

That is about €2,300/sqm. For Leipzig, that might still be acceptable, but you don't have much leeway with the budget.

Don't underestimate it. Outdoor facilities are a battle of materials and you also need the appropriate equipment to process it. I have calculated €12,000 for materials and equipment rental alone for the substructure, paving (not luxury, more like €35/sqm), spray protection, trees, lawn, house entrance. Garden shed and carport have their own calculation. Fences are not planned for now and neither is the little retaining wall around the terrace (the slope looked a bit smaller back then ;) )

That definitely worries me too and I can't estimate it. With the plan of where the house will finally stand, a landscape architect friend wants to make us a rough plan of how our garden could look and what is important so that it is no longer a complete mud desert. I am very curious about the result.

That's about €2300/sqm. For Leipzig that might still be acceptable, but you don’t have much room for maneuver with the budget.

Yes, you are right. We hope that through the self-performed work mentioned above (electrics, HVAC, flooring, painter) we will achieve a reasonable price. If the cost calculation is significantly higher, we will have to consider where we can save or what we can possibly do ourselves with a high time investment.

I probably gave that wrong.
Income €5,800
Expenses €3,415 (excluding cold rent)

Available income for loan and additional incidental costs - €2,385

Okay thanks - now I’m clearer :)
Have you already thought about whether you want to build with an architect or with an FH provider / general contractor?

1) The expenses seem quite high to me - you’re probably still in the phase where you’re happy to earn money and like to spend it. We are about the same age and spend around €2,500 per month (excluding cold rent), and I don’t really feel like we live frugally, quite the opposite. We always cook fresh and treat ourselves to everything we want :) So there’s definitely a big lever for you. €1,250 per person should be enough, or even less.

2) When it comes to house costs, I would calculate very conservatively, you can’t estimate it at all if you’ve never built before. I think the forum will agree with me here. Better to budget too much than too little. I would assume €3,000 per sqm in your place. That would be €450k for 150 sqm. The important thing is that the house stands - garage, carport, or similar you can add later. Keep in mind for own work that you also need time for it alongside your job, so I’d be cautious there too. In my opinion, it’s especially important that you have a price for the loan basis at the bank on a basis without own work. Then you can only save at the end and decide very freely (also depending on your life situation) what you actually do.

3) So overall, I wouldn’t take €527,000 but at least (!) €600,000 for the bank. If you have some left over, you either pay it back or invest it in outdoor facilities or the garage or you’ll come up with something (or special repayment).

4) With a €600k loan you have a rate of exactly €2,000 to the bank at 1.5% interest and 2.5% repayment, then a remaining debt of €347,853 after 15 years – doable.

5) If you have incidental costs of €500 and a rate of €2,000 then you need €2,500 month after month, which brings us back to 1).

If I were in your situation, I would go through with it and grit my teeth to fulfill my life dream.

How high is the speculation tax anyway? I would sell the 2nd property directly, then your financing will really be relaxed, even with children. Of course, that will cost you tax and possibly capital gains, but you can sleep peacefully. Of course, it also depends on your approach. Just calculate how much tax you would lose.

How high is the capital gains tax anyway? I would sell the 2nd property directly, then your financing will really be relaxed, even with children. Of course, that costs you tax and possibly capital gains, but you sleep peacefully for it. It's also a matter of personal preference how you approach it. Calculate how much tax you would lose.

Are you building with a developer? Make a deal with him... You sell him the property 1:1 for what you paid, he offers a fixed price with X discount included...

He then builds 2 houses there (which also reduces costs) and can sell them directly with a good markup...