Home financing about 500K - Can I afford it?

Hello, we plan to build within the next 2 years. Unfortunately, I keep getting different opinions on whether it is financially feasible. We are 31/30 years old.

Our current income is:
Mine full-time 2750 net
Wife 1400 net
Children 2 410

Total 4560 Euro/month
Equity 70000 Euro

Monthly expenses

Daycare 500 Euro
Cars (2 both paid off) 300 Euro
Mobile DSL 80 Euro
House incidental costs + reserves 750 Euro
Food 550 Euro
Miscellaneous 300 Euro

Monthly total 2580 Euro

Surplus 1980 Euro

With this, a financing of about 450,000 Euro should be possible, with a monthly rate of 1500 Euro.
Thank you very much

If the household budget is correct and the equity has been saved up by yourselves, it is indeed possible. However, not much will be left over, that must be clear to you.

Money was saved up independently, my parents pay club fees etc. for the children and would also provide a guarantee with their house (worth approx. 1.2 million). Would this be of interest to the bank for a better interest rate?

That would not be an option for me, with the equity you currently get great options.

[...] my parents, who would also guarantee with their house (worth approx. 1.2 million). [...]

With a golden parachute backing you, financing is not a problem.

Leave the parents' house out of consideration. The position car seems very low to me. Apparently, €300 only covers consumption and insurance costs?! A savings rate for replacement (later) would have to be added. Otherwise, it fits.