Roof Windows - U Values, Security, (not) Velux?

[drsilky]

I'm installing 3 Roof Windows in a rear, single storey extension that is 3m. Would somebody be able to give some advice please:

1) Because it's a single storey, do I NEED extra security or are the standard double glazed ones (that all seem to be toughened glass) enough?

2) There is a kitchen in the extension - is there an advantage to uPVC vs polyurethane coat vs wood?

3) Velux, Fakro, Keylite appear to be roughly the same price however the Rooflite/Duratech/Brite (which as far as I can tell are all the same company) come in significantly cheaper particularly for the size I'm looking at (780 x 1400 or 1040 x 1080). I know the u value might not be as good (0.1 or 0.2 difference) but does it make THAT much difference? They come with 10 year guarantee and I'm more concerned with safety and leaking though can't find any indication that they would be problematic.

Thanks again for the advice.

 

[Rad1o]

I don't know whether this is still topical being from December. We put some roof lights into a single storey extension and the loft. We went for Fakro. The smaller ones you get as triple glazed units and that makes a difference. For more insultion you can get roller shutters on timers.
Re. security our builder was joking that anyone could just climb onto the roof and unscrew the roof light from the outside and jump in. I don't know how often this access route is used for a burglary. I would guess you need a somewhat skilled and clever burglar.

 

[catlad]

You can't unscrew the window from the outside
and open it, plus why would you want to enter through
a window that was 3m+ above ground level.

 

[Rad1o]

I fitted the roof lights with the builder. Under a quickly removed trim we have 4 good size screws that fit the woof light to the rafters. Once they are out you can lift the whole window up. But I agree that people do not go in this way.

 

[masamune]

I fitted roofmaker (luxlite) in my extension, 2m x 1m they come triple glazed as standard. There are no screws on the outside and each panel weighs around 200 kg. I very much doubt anyone would try lifting it up to enter (even if screws were exposed), when it took 6 guys to fit it