ᐅ What is a sensible house-building planning process?

We have decided to build because existing properties here are sold at very high prices and still require renovation or refurbishment. Unfortunately, none of our family or friends have recent experience in construction, so we are currently a bit overwhelmed with everything. We want to build a turnkey prefabricated house since we are not skilled tradespeople and don’t have enough knowledge to contract the trades separately. We are planning to allocate around 100,000 euros (about 110,000 US dollars) for the land. Is it realistic to expect a turnkey house with a basement and 150-160 square meters (1,615-1,722 square feet), including the kitchen, for 250,000 to 300,000 euros (about 280,000 to 330,000 US dollars)? We are aiming for more than a basic level of finishes, so something at a mid-level standard. Energy efficiency is very important to us, so we are leaning towards a ground-source heat pump with a ventilation system that includes heat recovery, as well as solar or photovoltaic support. In any case, we want to be independent of fossil fuels. Is this feasible within the budget? Overall, we want to keep additional construction-related costs to a maximum of 450,000 euros (around 500,000 US dollars).

What would be the best next steps? We have already selected suitable floor plans. Today we are going to visit the prefabricated house center in Nuremberg. How do we find the right provider? Should we submit our plans to each potential company and request quotes? What about the building specifications? How can we compare the specifications if we don’t have much knowledge? We already have a few catalogs at home, and only one provider has sent us two detailed building specifications and price lists. They seem quite informative but also very difficult to understand for beginners… Are there any recommended checklists we could use to guide us through the process? Oh, and what kind of subsidies or incentives are available?

Thanks in advance!