Floor plan ideas and cost estimation for the renovation of a semi-detached house from 1939

Hello everyone,

after it has become clear to us (and made clear) that a renovation is better than an extension in the garden, I now want to ask for advice here again from the collective intelligence.

The facts:

- An architect has been commissioned and is already working on it. So far we find the plan nice.
- The semi-detached house basically dates from 1939. The living room on all levels is an extension from 1981. Just like the balcony and double garage.
- The ground floor is occupied by my mother. We live on the 1st floor. The attic is still rented out. The tenant knows that he has to move out. The loft was already partially converted. It was insulated with glass wool about 10 years ago. Basically only the painting is missing. It is supposed to become my office.
That means, we want to merge the 1st floor, attic and loft into one unit.

Previous ideas:

1st Floor:

- The existing staircase should be closed off downwards to the ground floor. For “family reasons” we want a separate entrance. The staircase upwards should however remain, or a new one be made (or restored?). It is still the original staircase from 1939.
- The front steps should run along the previous balcony. The stairs go up from north to south.
- Since we haven’t really used the balcony so far due to its dimensions (7 x 2m), it will be used to enlarge the old children’s room and future dining room with kitchen.
- The kitchen will become a windbreak/wardrobe and entrance area.
- The bathroom will remain as it was completely renovated just 3 years ago and will basically be the guest WC/bathroom.
- The bedroom stays.
- The living room stays but should become brighter. That means even bigger windows need to be installed.

Attic:

- Kitchen will become a utility room with washing machine and dryer. Also, a staircase to the loft/office will be installed here.
- Since the tenant smokes here and the children’s rooms must be added, we probably need to completely renovate the core (or?).
- The remaining space will become 3 children’s rooms plus a bathroom.

Loft:

- Will be an office. I would like it to be brighter and like more glass. If financially possible, I would like to have a large window somewhere, where I can nicely look towards the city center.

Costs:

- An energy consultant recommended by the architect was already on site. He estimates the renovation costs at about €370,000-400,000!!! That leaves me somewhat speechless. I had expected about half. Is it really that expensive??
He says that for subsidies we would have to do the entire roof. Estimation for the roof: €100,000. Technology €100,000. Interior finishing the rest. And at €370,000 more than 5 hours/day of own work is expected!! (!?) Otherwise it’s rather €400,000…
Google never shows me such high costs. Of course the costs are hard to estimate but I still find this quite a big deviation.
I would only want to have the roof done if it is really necessary or brings something. The focus is already on the interior finishing. The subsidies are currently not really that high that it makes sense to invest that much just because of that, right?
There is supposed to be underfloor heating and a ventilation system. But does that make the technology so expensive? The gas heating installed 16 years ago still works…

Questions:

- What do you think of the floor plans?
- What do you say about the costs?
- What would you have done and what would you rather leave out?
Our focus is on contemporary appearance (bright) and technology (underfloor heating and ventilation system).

How do you like the floor plans?

By posting them here along with the link to your old discussion. I still have the house in front of me, but that means nothing.

By putting it in here and also the link to your old discussion. I still have the house in front of me, but that means nothing.

You were just too fast.
But somehow the image upload does not work for me.

Here are the floor plans:

Upper floor:

Red is the old layout.
Green is the new one.


Attic:

The white walls are old.
The gray ones are the new plan.

Red is the old layout. Green is the new one. [...] The white walls are old. The gray ones are the new planning.

Izmir is too complicated. Synoptic representations are helpful, but not in this form.
As usual, you have certainly already seen this here. And then the most practical thing is to stick to the usual "color coding": existing stock in gray or black, new construction in red, demolition in yellow.

The existing staircase is to be closed off downwards to the ground floor. For "family reasons," we want a separate entrance.

You should also depict that; the ground floor is missing here and is confusing.

The semi-detached house basically dates from 1939. The living room on all levels is an extension from 1981.

I probably already said that in the old thread, that I don't believe the survey and would recommend clarifying how the house was actually built.

An energy consultant recommended by the architect was already on site. He estimates the renovation costs at about €370,000-400,000!!! That leaves me somewhat speechless. I had expected half that. Is it really that expensive?
He says for subsidies we would have to do the entire roof. Estimate for the roof: €100,000. Technology €100,000. Interior construction the rest. And with €370,000, self-performance of >5h/day is also expected!! (!?) Otherwise, it's more like €400,000...
Google never shows me such high costs. Of course, the costs are hard to estimate but I still find that a huge deviation.

> 5 hours per day ... SCNR, I have to quote the carrot: "no way, little Peter!" Does the energy consultant know anything about statics?
The by far (dangerously!) too high item is the estimation uncertainty. That here lies in the six-figure range!
I therefore strongly advise you to do very precise planning. Many renovation owners (and their old-building-inexperienced architects) build on the fundamental misconception that in existing buildings phase 1 can be done as a gloss-over. The opposite is the case; the effort is rather multiple times compared to new construction. Otherwise, you have to write "maybe" in front of every position and "or double that" behind. This is not yet the worst case, but it usually balances out in this magnitude.

Record and describe the status and measures very precisely!
The energy consultant should also clearly state for which measure which conditions regarding subsidies apply.

I currently lack the time to recap, but most of what I said in your old thread will also apply in the changed project horizon. At least I don't feel the need to write more here today.

I would probably rather access the ground floor apartment from the "balcony," meaning the front door there, and you keep the staircase. 1. cheaper, 2. I don’t find the straight outside stairs practical for everyday use with 3 kids. Energy-efficient renovation can be doubly subsidized through the granny flat on the ground floor. You should take advantage of that. Yes, building has become expensive, and renovation too. Where was north again? I think it can work without much fuss about floor plan changes like here.

He says for subsidies we have to do the entire roof. Estimate for the roof: 100,000 €. Technology 100,000 €. Interior construction the rest.

and where is the facade insulation item?