Insulate cold roof attic for office

Dear forum,

please excuse my ignorance - I have read through many threads but mostly I don’t understand much, and I am afraid that the local companies here won’t advise me very well either, since the roofers in our region all have a bad reputation. So I would at least like to be prepared before the first appointment so I can ask all the necessary questions.

Here is the matter: We have a 160 sqm attic, cold roof. OSB boards are installed, vapor barrier is present. The thermal separation to the living area is through an attic hatch that can be pulled down from below. We have been thinking: Since I am becoming self-employed, we actually lack a room in the house for an office. Therefore, we have considered partially insulating the cold roof so that I can create an office room. Is there any reasonable solution here, or would this be equivalent to a complete conversion and cost a fortune? I have also attached a few photos.

Thanks for any information!

Best regards, David

What do you imagine by "partially"? Separating a room with drywall and insulating it? Or a bit of insulation everywhere?

And it won't get warm by itself despite insulation; it only keeps the warmth in the envelope longer or better. Is there a heating system or an option for heating (other than electric) available?

Insulating the attic as a DIY project is basically no problem, only the (in my opinion nicely done) cold roof structure makes it problematic to do this afterwards :-( because of the missing vapor barrier.

Can you provide the details of the roof structure?

due to the missing vapor barrier/retarder.

That then goes on the insulation on the inside, iirc...
So actually not a problem either. I see the problem more in the missing heating as you pointed out and especially the missing ventilation. So there should be at least a window in the gable walls.

That then goes inside onto the insulation iirc...
So actually not a problem either. I see the problem more in the missing heating as you pointed out and especially the lack of ventilation. So there should at least be a window in the gable walls.

There will certainly be other solutions for that. It is supposed to be just an office and not living space.

I don't think so, I'm just an amateur too, but as far as I know, the vapor barrier must be installed on the inside underneath the insulation so that the insulation doesn't get soaked. And then heating is necessary because of the living space. When heating is on, the capacity of the indoor air to absorb water vapor increases. That means either the heating must be kept on continuously or ventilation must be done to get rid of the moisture.

That then goes on the insulation on the inside iirc...
So actually no problem. I see the problem more in the missing heating as you mentioned and especially missing ventilation. So there should be at least a window in the gable walls.

You are of course completely right regarding the position of the "intelligent foil." I was probably a bit confused ;-)

Then I would start and get insulation, "foil," lower battens and get going. Is there already OSB on the floor? Then I would lay good / thick carpet tiles there, it doesn’t cost a really big fortune. But insulation (mineral wool) is unfortunately a bit more expensive than a year ago. Rough estimate regarding the costs just for insulation, carpet, and interior cladding of the walls (plasterboard + paint) under 10K.

Careful work is mandatory for the sealing, the rest is a matter of taste.

P.S. Layman’s opinion, as always ;-)