Owning your own home

You have, with this post and others, unwittingly become my go-to passive cooling consultant.

Much like @Howard, we have a loft extension heat problem - during the London Summer month, the top bedroom can hit 35+°C, making it impossible to use.

This is in comparison to the first-floor mid bedroom, which is in shadow in the day, and has one external (solid) wall, that maxes out at 23 / 24°C.

It's only this year that I've really started to look at it, as with the house filling up with children, I can't just change rooms to the coolest one any more.

So far, I've been trying to mitigate it with selective window opening, (interior) shutter closing, and door opening / closing, but that only knocks it down a few degrees.

I've just shelled out for external awnings for the Velux windows - per your comment, stopping the sun before it gets to the windows seems smart - and also some more reflective blinds.

I rather feel, though, that the real problem is that the extension was built on the cheap, and the insulation in the roof is well below building regs for extensions (not that it was ever signed off...) - I've chucked a load of PIR between the roof rafters in the eaves (as there was none), and when doing so, could see that there is what looks like a very cheap thermal quilt in the main roof space.

Out options appear limited to:

• Close the door, and give up the room over Summer,
  
• A split aircon unit, with solar panels powering it so that I don't feel too much like an environmental disaster
  
• Rebuild the roof with more insulation (the rafters aren't deep enough to have think PIR and adequate ventilation
  
• Is there such a thing as roof shades?