Sorry FernandoT I've only just picked this up. I don't visit this site too often.
Its been (since Oct 2013) 4 months since fitting the new guardian roof.
Firstly, the warmth is great and this is throughout the down stairs of the house. Before fitting the roof (which from the earlier post was polycarb) the down stairs was cold in the first year of moving in.
We had loft and cavity done first, followed by some larger radiators fitted down stairs, but the conservatory was both large and open as a room from the kitchen.
My kitchen is around 16 feet by 25 feet so is a bit big and the conservatory as mentioned is also quite large.
The heat down stairs was never being contained and the house would grow cold very quickly.
We fitted the Guardian roof (please note there are many others out there so pick the one for you) and noticed a considerable difference. Now the house retains 18 degrees down stairs whereas it would often drop to 8 degrees in the kitchen and conservatory.
It takes around 60 minutes to bring the rooms back to 20 degrees and we use the heating in the morning and at 4 to 5 pm for about an hours (so 2 hours a day) and the house keeps at temperature.
A couple of problems :
1. We haven’t tried this in summer yet so don't know how it will perform, I will write later in the year.
2. The ceiling plastering is not the best but this was down to the skills of the builders not the roof itself. For example our shape is a P shape and the left side has a dome which has been left more hexagonal than circular inside by the plaster work and the lines are not straight which shows. We didn't see this until we painted the ceiling white.
But that’s a workman ship problem.
3. We haven't notice the lost of light by having a solid roof, this is because its white but also we are South facing
All in all we are very pleased and although it takes a long time to recover 10 grand its money well spent for me.