I can still throw WBI Massivhaus into the ring. They build locally, solid (Poroton) but with Futura floor slabs. Just take a look. Otherwise, two appraisers recently independently recommended Stollhaus in case of building during house inspections. They apparently made a positive impression on them as appraisers. Besides that, I still have Generalbau Peter, Meisterbau Nord, Nagelbau, and Trave Massivhaus on the list.