Air Brick to Nowhere! Developer fail or standard practice?

[rlw83]

Hi all, expertise needed!

In the hunt for causes of heat loss, I've just discovered something odd.

Our 2007 brick-cavity house has two 9x9" exterior air bricks which have square, terracotta ducting going through both wall 'skins' and butt up roughly to the INTERIOR plasterboard wall. Inside it's dot'n'dab but the ducting doesn't appear to vent directly into the dot'n'dab cavity apart maybe from via the rough edges of the duct - see photo. This causes two REALLY cold patches on the interior wall and surely isn't standard practice.... is it?

The house is cavity wall construction with polystyrene bead cavity insulation from new (no signs of retrofit). It has everything else you'd expect... under-floor air bricks on the other exterior walls, weep vents over cavity trays, windows with trickle vents.

So is this standard practice or a design flaw?

Since these bricks can't be providing much ventilation to anywhere, can they be safely blocked up?

Thanks
1. View from inside the airbrick of the back of the interior plasterboard

Air brick exterior

 

[robinbanks]

surely isn't standard practice.... is it?

Expecting the average volume house builder tradesmonkey to understand the finer points of air tightness and insulated envelope is an exercise in futility I'm afraid

Are you saying the cavity is fully filled with beads everywhere else but here?

 

[rlw83]

Are you saying the cavity is fully filled with beads everywhere else but here?

Yes the cavity is filled elsewhere but these air bricks are ducted through BOTH walls so the insulation is contained. What I'm concerned about is why the air bricks are even there other than to cause a cold spot on the internal plasterboard? Could they be filled?

 

[robinbanks]

Original house design had some massive log burner and building regs said it had to have X square metres of air inlet to the room maybe

 

[jeds]

That would be my guess - the vents are most likely air supply to gas or log burner. Or should have been!