Loan amount - What is achievable?

First, define what you need and what the market offers. If you tell me financing 500k, I say no. Max 350k.

Now you've already revealed almost everything anyway, please organize and compile everything again so that one can see what the situation actually is

- Immo1 condominium rented out:
Value: xxx
Encumbered with a mortgage: xxx of which not yet repaid: xxx
Rental income xxx
Expenses xxx (loan installment, share of community costs, etc.)

- Immo2 condominium occupied:
Value: xxx
Encumbered with a mortgage: xxx of which not yet repaid: xxx
Rental income (theoretically possible) xxx
Expenses xxx (loan installment, share of community costs, etc.)

- Immo3 building plot:
Value: xxx
Encumbered with a mortgage: xxx of which not yet repaid: xxx

- Other loans/ car leasing/ liabilities etc.? Each amount and how much repayment is still outstanding?

- Equity: cash, overnight money, other investments, home savings contract (term?, how much longer must it still be serviced? how much could already be withdrawn?)

Then compare all current expenses with the total income.

Depending on the overall situation, you can either build a palace or just set up a party tent on your building plot.

Alright, then here is a summary once again:

- Immo1 condominium rented out:
Value: approx. 120,000
Encumbered with a mortgage: 50,000, the other part of the mortgage is on Immo2
Outstanding loan: almost the full 120,000, as it was a 100% financing and the purchase was recent.
Rental income 550 euros cold (net rent)
Expenses 300 euros monthly (loan installment, community fees, etc.)
Remaining debt after fixed interest period 2028: approx. 100,000

- Immo2 condominium lived in:
Value: 160,000
Encumbered with a mortgage: 70,000 remaining from Immo1 for Immo2 mortgage on the parents' house
Rental income (theoretically possible) calculated conservatively 750 euros
Expenses 145 monthly (loan installment, community fees, etc.)
Remaining debt after fixed interest period 2028: approx. 50,000

- Immo3 building plot:
Value: approx. 120,000
Encumbered with a mortgage: 50,000 of which 40,000 still unpaid

- Other loans/car leasing/liabilities etc.? How much each and how much still outstanding? No other loans or liabilities.

- Equity:
Cash/daily allowance approx. 30,000
Emergency reserve in an additional account: 10,000
Other investments stocks: approx. 8,000
Building savings contract (Bausparer) 50,000 paid in, 100,000 can be borrowed at 1.4%

Current income is about 3,800 euros, with an upward trend. We are both employed in the public sector, where you advance through the salary levels over the course of your career.
For example, my wife is currently still at level 1, so it will increase significantly in the coming years.
Also, she works "only" 50%, which will increase as the children grow older.
Christmas bonus/performance-based pay I am leaving out here for unforeseen expenses.
Also, the very high costs for the daycare will fall away in the fall.

For the house construction we would now need to finance 400,000 for the house itself and the current remaining debt on the plot. So a total of 440,000.

Do you think this is realistic here?

Or should we rather pay off the plot first and continue to save equity?

Depends on what you want to hear!
If you want to hear whether you will get financing: maybe?
If you want to hear whether the financing is healthy: definitely not!

So many liabilities, a low income for Bavaria, and then take out 440k on top of that. I couldn’t sleep peacefully at night anymore. You will definitely get the money, but you have to expect to pay it back with a rate of half your income... I would never do that.

Something seems to be miscalculated with Immo 1. After 10 years, only €20,000 of the loan has been repaid?