Well, it makes little sense to write down individual construction times here, as it depends on personal circumstances how long such a build takes. You have to plan for at least 1 year; anything else is guesswork. If your husband is often not on site, it is important to have proper site management, and by that I don’t mean the developer’s employee. Without grandparents to support you, you won’t be able to do much yourselves, unless you want to tie your child to the construction stairs to be able to paint in peace :-) Here you should just budget for a professional painter/floor layer. And building with an architect would not be the first choice either. Unless you can and want to drag your child everywhere, from the architect to the window maker and to the tile studio... you save yourself a lot of stress and running around if you go to the sample selection and leave the child with the grandparents in the meantime. I don’t quite understand your last point, what do you mean by "not living alone in the house later"?