Cost estimate for old building renovation

Hello forum,

Parallel to my other thread about financing the renovation of the old building, this one is about the total cost estimate.

The following facts: The house is still occupied on the ground floor by my wife’s grandmother. No renovation is planned there. The upper floor (100m2) will remain as per the layout except for two walls that will be removed. Floor coverings (cork in parquet look) and wall coverings (painted plaster) will be installed by ourselves. In addition, there will be an extension of the warehouse which will add an additional 60m2 of living space. The attic (100m2) will be extended upward by about 1.20m. The roof including the rafters must be newly constructed on top. The 60m2 extension serves as a roof terrace in the attic. A dormer with a terrace door must be planned here. The whole thing should reach approximately [KfW 70 Standard]. Trades carried out by friends and acquaintances are the following: architect, mason, gas, water, electricity, tiling, heating installer, and the kitchen at staff discount.

What do you think the estimated costs will be?

Greetings from the Palatinate

Year of construction of the house 1960 with extension from 1970.
A few more additions...
External insulation + new plastering.
Underfloor heating on a total of 260m2.
Gas condensing boiler or pellet heating.
All new electrical installations.
All new water services.
A precast concrete staircase to the upper floor in the outdoor area. A wooden staircase to the attic inside the house.
1 sliding patio door, 1 front door, 10 interior doors, 1 glass sliding door, 2 windows measuring 140cm x 120cm in the attic. New windows were installed in the upper floor just 3-4 years ago, which should remain.

I know I can't expect any numbers. Nevertheless, I would be interested in your opinion on whether I could manage with the targeted 225,000€.

So with the scope, including the extension, new beams, etc., I doubt that YOU will manage with 225,000 EURO.

For comparison. Acquaintances of mine renovated a 200sqm house (roof, windows, ETICS, water, electricity, heating, doors, floor coverings). They ended up just under 170,000. And they did a lot of work themselves.