External insulation or windows first

SemperFidelis

Hi,

I've bought a cavity block house with single glaze windows and no insulation at all. After reading through boards I believe external insulation is the only option for this type of house. I plan to also get some good double glaze windows too.

So my question is from the point of view of the finishing which should I get done first, external wall insulation or double glaze windows. Both will have an impact on the finish around the windows/sills so I'm wondering is there a preferred order.

Thanks

Melendez

This post has been deleted.

sinnerboy

Windows first most definitely .

They will be losing heat on a per m2 basis , about 3 times faster than the walls are. ( Approx wall U value will be 1.7w/m2K , window approx 5.1 W/m2K).

Assuming windows equate to 25% of wall area you get by way of simplified example ( wall area being 100m2 , windows being 25m2)

100 x 1.7 = 170w/k loss through walls
25 x 5.1 = 127.5 w/k loss through windows.

Despite the smaller area , the rate of heat loss through the windows almost evens the score. Furthermore the heat you lose through single glazing is very sensible by that I mean physically sensible - the human body really feels it. The low surface temperature of the single glazing seems to suck the heat from you.

SemperFidelis

Many thanks for the replies,

I'll try get both done together but unless I get a great quote for the insulation it'll likely be windows first then.