Extra loft insulation, I can't believe it works!

ThisIsWeird

H143, you already had a quite decent 200mm of insulation up there? Was it particularly badly laid?!
Sorry, I'm with the somewhat sceptical on here - adding extra insulation is not as transformative as adding the first layer, for the simple reason that the first layer has already done 'most' of the work.
If the first 200mm layer cut the heat loss through the ceiling by, say, a factor of 10 (plucking simple figures out of the air, of course), then only a tenth of the heat loss is going to be hitting this additional layer, so even if it's as effective as the first, it can only improve matters by a further tenth of a tenth. 
Insulation follows the law of diminishing returns.
Unless, of course, the new layer sorted out bigger issues up there like insulation gaps, draughty hatches, that sort of stuff.
Tbh, when we first had LI installed, I didn't notice. When we had it topped up to the recommended levels a few years later, I didn't notice. I'm sure it helped - it must have - but not to any physically sensed degree.

Swipe

Well, the weather turning from sub zero to 7C made a huge difference for me

Eldi_Dos

Swipe said:

Well, the weather turning from sub zero to 7C made a huge difference for me

Which would suggest that improving the insulation and draught proofing would make temperatures more stable in the house.

Swipe

Eldi_Dos said:

Swipe said:

Well, the weather turning from sub zero to 7C made a huge difference for me

Which would suggest that improving the insulation and draught proofing would make temperatures more stable in the house.

Yes, I have next to zero insulation (30mm at best)  in the crawl space around my converted loft. I have a complete re-roof booked in for next year so will all be addressed then as part of the job as per the building control regs.

Eldi_Dos

Swipe said:

Eldi_Dos said:

Swipe said:

Well, the weather turning from sub zero to 7C made a huge difference for me

Which would suggest that improving the insulation and draught proofing would make temperatures more stable in the house.

Yes, I have next to zero insulation (30mm at best)  in the crawl space around my converted loft. I have a complete re-roof booked in for next year so will all be addressed then as part of the job as per the building control regs.

You will notice a difference next winter then.
Once had a attic bedroom like that freezing in the winter and too warm in the summer, wish you well with the work when its being done.

A younger relative moved into a new build about fifeteen months ago and it is noticeable how comfortable the house is.
No great temperature swings just comfortable,they have been pleased with bills as well.

Chickereeeee

Once had a attic bedroom like that freezing in the winter and too warm in the summer, wish you well with the work when its being done.

As with pretty much all loft conversions that I have come across.