Preferred position for Velux windows?

[Mick6]

Is there a preferred position for Velux windows (closer to the original house wall or closer to the new exterior wall?) in the roof of a single storey extension to maximise light penetration into the original house?

I was going to place them midway between the two but I noticed that someone across the way has got them very close to the original house wall. The extension is three metres deep, the room behind which previously had a patio door to the outside, about 3.5 metres.

Also, is there any guideline figure for window area? We're looking at putting two 780 x 980mm windows in a 6 x 3m roof area.

Thanks for any advice.

[Tony Bryer]

I suspect most people locate them having regard to what is underneath. Do you want to lie in bed looking up at one?

[keith_765]

The lower down the roof slope the more floor area light. The higher up the roof the light will go further back into the room.

[LSR]

If the extension roof is shallow enough to walk on, it's a good idea to leave enough space between the original wall and the Velux windows so you can wash the upstairs windows and clear the gutters comfortably.