ᐅ Insulating a cold attic roof for use as an office space

Dear Forum,

Please excuse my lack of knowledge – I have read through many threads but often feel completely lost, and I’m worried that local companies here might not give the best advice, as the roofers in our area generally don’t have a great reputation. So, before the first appointment, I would at least like to be prepared to ask all the right questions.

Here’s the situation: We have a 160 m² (1,722 sq ft) attic with a cold roof. OSB boards are installed, and there is a vapor barrier. The thermal separation from the living space is through an attic hatch that can be pulled down from below. We have been thinking: Since I’m starting my own business, we actually need a room in the house to use as an office. Therefore, we considered partially insulating the cold roof to create an office space. Is there any practical solution for this, or would it be equivalent to a full conversion that would cost a fortune? I have also attached a few photos.

Thank you for any information!

Best regards, David

What do you mean exactly by "partially"? Partitioning a room with drywall and insulating it? Or adding some insulation here and there?

And insulation alone won’t make it warm; it just helps retain heat longer and more effectively within the building envelope. Is there a heating system or an option for one (other than electric) installed?

Insulating the attic as a DIY project is generally no problem, but the (in your case nicely executed) cold roof construction makes retrofitting insulation difficult :-( due to the lack of a vapor barrier.

Can you share the details of the roof structure?

i_b_n_a_n schrieb:

regarding the missing vapor barrier / vapor retarder.

That would go on the inside of the insulation, if I recall correctly... So it’s basically not a problem. I see the issue more with the missing heating, as you pointed out, and especially the lack of ventilation. At least a window should be installed in the gable walls.

Tolentino schrieb:

If I recall correctly, that is applied on the inside of the insulation... So it shouldn’t really be a problem. I see the bigger issue as the missing heating you mentioned, and especially the lack of ventilation. At least there should be a window in the gable walls.

There will surely be other solutions. It’s supposed to be an office, not living space.

I’m not an expert, just an amateur, but as far as I know, the vapor barrier should be installed on the interior side, beneath the insulation, to prevent the insulation from getting wet. Also, heating is necessary because it’s a living space. When the space is heated, the air’s capacity to hold moisture increases. This means it either needs to be continuously heated or ventilated to remove the moisture.

Tolentino schrieb:

That is supposed to go on the insulation on the inside, if I remember correctly...
So actually not a problem. I see the real issue more with the lack of heating, and especially the missing ventilation you mentioned. At least there should be a window in the gable walls.

You are absolutely right about the position of the "smart vapor barrier." I was a bit confused there ;-)

Then I would get started and buy insulation, the "vapor barrier," UK battens, and begin. Is there already OSB on the floor? Then I would lay down good, thick carpet tiles there; it doesn’t cost a fortune. However, insulation (mineral wool) is unfortunately a bit more expensive than a year ago. Rough estimate regarding costs for insulation, carpet, and interior wall finishing (drywall + paint) is under 10,000.

Working carefully on the sealing is essential; the rest is a matter of personal preference.

P.S. Layman’s opinion, as always ;-)