So, I would find it more relaxed, cheaper to build and to need only, say, 240 instead of 290. I think, with the equity status quo, a 1000,- euro rate per month is enough. I don't think you should calculate yourself rich for the future. You are not immune to unemployment, the children might go to university and be expensive. Etc pp. 240 would be without interest, at a thousand euro rate, 240 months or 20 years. With interest maybe 25. Then the fish should be cleaned, and you debt-free. K.