ᐅ Complete Renovation and Modernization of a House in 1986 – What Were the Costs?

Hello community, I would like to ask for your assessment and experience once again.
We are considering buying a house from 1966 with approximately 160m² (1,722 sq ft). The location is unique for us.
The condition of the building is good.
We can contribute with our own work for the core renovation, demolition of the old roof, creating openings, etc.
We will definitely involve an architect with a structural engineer or a building contractor.

We have big plans and would like a rough estimate of the costs we should expect:

- Roof/attic extension of about 110m² (1,184 sq ft), open to roof style, with photovoltaic panels
- New heating system (probably heat pump with underfloor heating)
- All windows on the ground floor (including a panoramic window)
- All windows on the upper floor (extension with panoramic window)
- Various wall openings
- Staircase renewal to the upper floor
- Conversion of a small room into an entrance area with a front door
- New electrical wiring, water pipes, and sewage pipes
- Exterior wall insulation
- New double garage

There are no available building plots in our region.
Would you recommend demolition and new construction for our project?
Or could the project be worthwhile with good planning?

Thanks for all tips, experiences, and cost estimates.

Full renovation of 160m2 (1,722 sqft) without personal labor and additional vertical extension?
160 * 3000 for the renovation + a flat rate of 50,000 for the vertical extension.
530,000 € without really knowing the project.

I would have also guessed around half a million. It’s no different than if you demolish it.

Why do you want to renovate against the house rather than with the house?
- Changing windows
- Wall openings
- Adding an additional floor
etc.
These factors can drive the costs so high that building new would cost the same.

I am confused: according to the title, the house dates from 1986, but the text says it is twenty years older; and its size is 160 m² (1,722 sq ft), but it is supposed to grow to 110 m² (1,184 sq ft) through an extension?

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https://www.linkedin.com/company/bauen-jetzt/

There is an incorrect number in the headline that I am unable to change. The house was built in 1966.
The current attic has only about 35m2 (375 sq ft) of living space. After adding an additional floor/raising the roof, the upper floor would then have 110m2 (1184 sq ft).

Flo1990 schrieb:

There is a wrong number in the headline that I cannot edit. The house was built in 1966.

Okay, 1966: high likelihood of cast iron drainage pipes, lead water pipes cannot be completely ruled out; electrical wiring probably still original but too minimal by modern standards; wet rooms fully in need of replacement. Overall, a full renovation down to the shell.

Flo1990 schrieb:

The current attic has only about 35m² (375 sqft) of living space. After a roof/loft extension, the upper floor would then have 110m² (1184 sqft).

So from a 1-bedroom + living room (total 160m² (1722 sqft)) to a 2-bedroom + living room including the roof space—but not fully converted for living?
Photos and existing floor plans and cross-sections would be helpful.

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https://www.instagram.com/11antgmxde/
https://www.linkedin.com/company/bauen-jetzt/