I used to erect timber frames about 17 years ago I can’t remember there ever being a vcl fitted, it was just insulation then we boarded it and rarely was it foil backed . We always fitted a breather membrane though.
Is it because of increased airtightness that they’re needed now?
My current new build has had the vcl drilled and screwed into by the blind fitter adding those safety clips for the cords.
will this have any affect on the timber frame and insulation going forward?