Just for comparison: I signed the construction contract for a prefabricated house in timber frame construction and the loan agreement in May 2018. The construction contract with the description of construction services listed everything with the total amount, minus all the trades I did myself (underfloor heating including insulation, sanitary installations, roof drainage, painter from Q3, floor coverings), split into material and labor costs. I had to additionally sign these labor costs (about 22,000 EUR) separately and also provide them to my financing bank, besides the description of construction services. The building application was submitted in August, a mini-sampling and production go-ahead for the prefab house in October, demolition of the existing house + earthworks in October, approval in mid-November, foundation slab in mid-December, house erection in mid-January, and from then on the self-performed work started, partly in parallel with the official trades. The screed came in mid-February, then there were delays with the heat pump and the screed heating because the power connection was not installed, handover at the end of May, move-in in mid-June. I did not do the masonry, excavation, pour the foundation slab, install windows or doors, do electrical work, or do the Q2 plastering myself. You want to do all of this yourself, partly even while working. I have trained tilers, painters, installers, and heating technicians within my circle of friends and family, with whom I previously clarified that they have time and that I can schedule them. Your 9 months will not be enough. And honestly: the motivation decreases week by week. I prepaid all material costs from my own (not specified separately for this reason) equity since the bank only paid out after presentation of the invoice. After completion, an appraiser came who wanted to see all rooms and take photos of almost all rooms; he asked questions about KfW standards, floor coverings, equipment, etc.
