Drilling in a vapor barrier

[AlexMcHugh]

Hello!
I need to install a heat pump in an extended part of the house, where the extension was built in 2000.
It's located by an attic hatch and the installer wants to put in an attic hatch (60x60) to make it easier to run the cables.
I asked about the vapor barrier and how it would be affected, but he said it wouldn't be a problem.

However, it felt like he didn't really know what I was talking about. Is what he said really correct? The house has mechanical exhaust ventilation, if that might affect anything.

Grateful for help!

 

[falkn]

The important thing is that the vapor barrier seals against your attic hatch and that the hatch is also sealed against its frame.

 

[AlexMcHugh]

That feels reassuring, then I work with ångspärrtejp at the edges of the hatch and ensure that the hatch is sealed against the frame.