Dream of a house possible?

Hello, I am new here and happy to have found this forum. We also have the dream of owning a house and would like to buy/build a house especially because of the current low interest rates. Here are the current details: I am 39, employed in the public sector, currently on parental leave until at the latest May 2012, then income of about 850 €, my husband is 42 years old, also in the public sector, income of about 2370 € and additionally child benefits of 368 €. The family planning is complete. I would like to know how much credit we would roughly get? Unfortunately, I must also mention that we still have 30000 € of remaining debt, due to a so-called junk property. Is there a possibility to somehow refinance this amount as part of the construction financing? Or are there other alternatives? I know that it is probably not sensible, but the interest rates will probably not be so low in at most 2 years, when I also go back to work.