ᐅ How should the connection to the sunroom be properly insulated?

We are currently having a house built with an attached sunroom. A sunroom is an unheated conservatory. A friend of ours, who is a master mason and owns a construction company, recently inspected the building shell and was surprised that the slab of the sunroom is directly connected to the house’s slab without insulation. In his opinion, insulation should have been installed here—just like on the other exterior walls—to prevent frost from traveling beneath the sunroom’s concrete and reaching the living room floor. Otherwise, we would have to compensate by heating the living room.

Our contractor should have known this because we clearly told him that the sunroom would be unheated.

What are your thoughts on this?

Heidi1965 schrieb:

and we have to heat up the living room because of it.

I have no idea what the professional standard is. But "heating up against it" always sounds good. Whether you end up wasting 1€ more per month during the winter months because of this "botched work" or not, it doesn’t matter. In fact, it has no impact on the heating costs.

Why does it have no impact on heating costs?

Heidi1965 schrieb:

Why doesn’t it affect the heating costs?

Because it concerns a very small area compared to your building envelope. Just a few centimeters (inches). Of course, some heat is lost there, but it is negligible. Similar to an attached balcony. You won’t notice any difference.

Okay. That reassures me. Thank you!