Velux in Attic

creedp

I'm building a 1 1/2 storey in which I was originally of the view that the attic would be so limited that it would not be worthwhile installing an attic velux. However. the roof is now going on and it is clear that the attic space will indeed be quite substantial so as to offer reasonable storage opportunities. Consequently, would people be of the view that installing an attic velux would be worthwhile in this case or would it create more problems than it solves.

On an similar note my wife wants to install a velux in a bedroom that has one south facing window because every other bedroom has 2! I'm concerned about the cold bridge implications of having the 'light tunnel' through the attic into the bedroom in addition to the potential overheating and lighting of the room during the summer. Would these concerns be something that others would share?

Thanks

RKQ

creedp wrote: »

I'm building a 1 1/2 storey in which I was originally of the view that the attic would be so limited that it would not be worthwhile installing an attic velux. However. the roof is now going on and it is clear that the attic space will indeed be quite substantial so as to offer reasonable storage opportunities. Consequently, would people be of the view that installing an attic velux would be worthwhile in this case or would it create more problems than it solves.

A velux on the rear elevation would add natural light to the attic store. Discuss same with your Certifier / Designer.

creedp wrote: »

On an similar note my wife wants to install a velux in a bedroom that has one south facing window because every other bedroom has 2! I'm concerned about the cold bridge implications of having the 'light tunnel' through the attic into the bedroom in addition to the potential overheating and lighting of the room during the summer. Would these concerns be something that others would share?

Thanks

A new velux on the front elevation will require planning permission. Discuss same with your Certifier. You do not say which elevation you would install this velux on?
On a personal note I see no problem with an insulated light tunnel to a velux rooflight. Natural day light would out weight overheating in summer, as velux or windows are easy to open for ventilation. A well designed & installed light tunnel should not cause a cold bridge.

creedp

RKQ, thanks for the advice on both issues. The velux for the bedroom is on the rear elevation and has already been included for planning. I was just concerned that with the high level of insulation now installed in attics, that it might be difficult to attain a similar std with a light tunnel and therefore the additional light might not be justified.

Also in relation to the insulation of the attic floor, I was planning to put down 300mm of rockwool when I though the space would not be used but now that I am considering using it for storage etc what types of insulation would be best? I could still put 150mm of rockwool between the joists but what would people suggest above the joists?

Thanks

bbam

Hi..
We built a 1.5 story about 18 months ago, we have 2 velux fitted in the roof line and they are great, the floor is ply'd out so it's great storage with natural daylight..

We have 300mm rockwoll and 50mm insulated slabs on the under side of the joists...

I'd say put in the velux as it would be a much bigger deal to do it in the future...

The Barrier

we are building a 1.5 wall plate dormer as well. We have put in 8 inch joists with high density rigid insulation between joists backed on the ceiling side with 38mm insulated plasterboard. We're flooring attic space.

clint_eastman

bbam wrote: »

Hi..
We built a 1.5 story about 18 months ago, we have 2 velux fitted in the roof line and they are great, the floor is ply'd out so it's great storage with natural daylight..

We have 300mm rockwoll and 50mm insulated slabs on the under side of the joists...

I'd say put in the velux as it would be a much bigger deal to do it in the future...

I'd agree, I put in 2 veluxes in the attic at the back of the house to allow natural light. I'm interested to hear on your insulation build up, that is very high spec (300mm rockwool + insulated slabs), did you use 12" joists? I used 9" which now means I have to come up with another method to allow me floor out the attic.

creedp

clint_eastman wrote: »

I'd agree, I put in 2 veluxes in the attic at the back of the house to allow natural light. I'm interested to hear on your insulation build up, that is very high spec (300mm rockwool + insulated slabs), did you use 12" joists? I used 9" which now means I have to come up with another method to allow me floor out the attic.

Thats my issue now as well as I only have 6" joists and if flooring out the attic I wont be able to achieve the required level of insulation unless I use some form of rigid insulation board on top of joists.