Airtightness for Flush Mounted Consumer Unit

MortarThePoint · 2026-06-12T14:26:46Z

I've agreed with the sparky that I am going to have a satellite consumer unit (CU) for an attic conversion. That way, I have a single feed to the attic and then dedicated isolator, RCBOs etc for the attic sockets, fans and lights etc. I am planning to put a flush mounted consumer unit into a stud wall that has an airtightness requirement. I'm not expecting to achieve airtightness with the CU itself[1], so am thinking I'll create an OSB box behind the plasterboard that is lined with Passive Purple (air tight paint) and has sealed entries for the cables. The airtightness membrane of the wall would then get tape sealed to this OSB box. Is that how airtightness is normally done for flush mounted consumer units?

I like the look of the flush mounted consumer unit below. I know Hager also make a good one, but I feel it's a bit industrial looking for being visible on a wall in living space. Hopefully this one doesn't actually have the logo on it, but if it does a pit of paint could easily solve that. Has anyone used a Live brand consumer unit?

[1] I know Wiska do airtight cable grommets you can get from TLC, but attaching the membrane to the CU housing sounds tricky.

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