Costs for building a house in the year 2024

Just my experiences (as also posted elsewhere) regarding construction costs. From my point of view, it all depends on the topic of own work. We started building in spring 23 and recently moved in. Below are a few smaller key data points:

Construction location: OWL (NRW)
Plot: Available
Cost for the house: €420,000
Area: 180 sqm living space + garage
Mono-pitched roof, Viessmann heat pump, photovoltaic system, 1 main bathroom + 1 guest bathroom with small shower, no basement, "normal" electrics (no KNX or similar).

Below are a few single items I have in mind right now:

Shell construction + base plate + earthworks: €140,000
Roof/carpenter: €42,000
Sanitary/heating/air conditioning: €35,000
Plaster (interior/exterior): €35,000 (we had real quality problems here -> better to spend a bit more or choose the company better)
Photovoltaic system: €13,500
Windows: €40,000
Screed: €9,000 (fast-drying)

Floor plan was designed by an architect.

Own work:
Installation of the photovoltaic system (10kWp + storage)
Helping with roofer work (screwing rafters, covering roof, installing gutters, garage slope insulation, etc.)
Filling concrete ceiling
Wallpapering/painting children's room, dressing room, storage room, utility room myself
All chipping work for electrics done by myself (company only marked)
Floor work except tiling done myself
Vapor barrier + insulation between rafters
Laying floor insulation + underfloor heating pipes
Installing window sills (inside/outside)
Installing "normal" windows myself (under the guidance of a professional) -> lift-and-slide door and large elements were done by the contracted company
Roller shutters/motors also done myself
Drywall construction

But: From June 23 until the end of January 24, I was on the construction site every Saturday (all day) and almost every day after work from 4 p.m. and did at least something until 8 p.m.

Feel free to ask for details. This is just a "rough" overview for now.