ᐅ Insulating the Attic / OSB Boards

Hello fellow homebuilding enthusiasts,

New construction KfW70 single-family house.

We are currently deciding whether to insulate our attic space right away and whether to install OSB boards at the same time. The carpenters don’t have a clear opinion on this.

I would like to hear some advantages and disadvantages; right now, I only see the financial aspect. Both together would cost me about 2400 € net additionally. A colleague of mine said today that he wanted to save money on his new build but now is willing to invest. He would have it done right away.

Cross-sections attached.

Looking forward to your suggestions.

Disadvantage: it costs money.
Advantage: then it’s finished and done, and you can properly use the attic space right away.

We had it done in our current house and will have it done again straight away in the new house.

Yes, exactly, that’s what I think too.
Are there really no disadvantages except for the financial aspect?

Of course it exists; you then have extra storage space that you fill with unnecessary clutter and will eventually need to clean up.

But I would also have it done right away.

Ok. Then you might be able to save some money by just installing the OSB boards. The insulation doesn’t seem to be absolutely necessary.

Thanks for the help!

But if you don’t insulate at the top, won’t you lose a lot of heat? Heat rises, after all.
Is your roof insulated all the way to the top?