House construction planning for a single-family house of approximately 170-180m²

What is your assessment: Do you expect prices (including raw material prices) to decrease somewhat again in the next few years?

Why should they? What has become cheaper in recent years, except for "electronic waste"? Even there, you have to dig deeper in your pocket if you want something nice (I deliberately do not write high-quality). The price spiral will continue to turn unstoppable and there is only one direction.

since I have often read something about 1.5k to 2k per m2 here in the forum.

No. I have been active in the forum for 7 years and these numbers are unfamiliar to me. 2013: From 1600, Energy Saving Ordinance 100, painter excluded, general contractor standard plastered. Plus incidental construction costs etc. An architect calculates differently, he calculates the enclosed space and including the incidental construction costs. The numbers he mentioned of 3.5 thousand will probably be roughly all costs, including his fee services.

Currently calculate with 2,500 € / sqm for simple equipment. That makes 450,000 just for the house without incidental costs, etc.

I would calculate that as well. Simple rectangular construction with gable roof, underfloor heating, normal roller shutters. Kitchen, outdoor facilities, garage, incidental construction costs come on top. However, I don’t know the Bavaria surcharge.

so, I can confirm about 3,500 EUR / sqm for the Frankfurt area. After all, high-quality and including additional construction costs.

Funny how everything gets mixed up here. It is really important whether you compare with or without ancillary construction costs.

3,500 euros per m2 probably includes everything except furniture and land. You can calculate it that way. Personally, I recommend 2,500 per m2 plus ancillary construction costs, garage, basement, upgrades, equipment, garden, terraces, and miscellaneous.

You can easily build 170m2 without a basement for 600k in Bavaria. No problem at all, not even currently. For that, you also get high-end equipment (ventilation, heat pump, good windows, high-quality parquet).

so, I can confirm about 3,500 EUR / sqm in the Frankfurt area. After all, high-quality and including additional building costs.

Now that's a detailed and explained statement!

. Personally, I recommend 2500 per m2 and then plus ancillary construction costs, garage, basement, upgrade features, garden, terraces, and other items.

Strange recommendation. Personally, I much prefer the tutti kompletto figure as a rough guideline (because all of this is only rough).