Planning one of those rooms with a glazed roof panel?
You really need to think very carefully before you go ahead!
In summer the heat gain and glare can be enormous causing major overheating. A typical North facing 900mm x 900mm sky light can put 3kw of heat an hour into your room between 9.00am and 3pm.
Sky lights are difficult to shade effectivly, although putting them on a South facing roof can help. Don’t forget though in most of Australia the sun is almost directly overhead in summer.
As heat naturally rises in a room high level windows can lose 30% more heat than a typical window in a wall. Even with double glazing you will be loosing far more heat than would be the case for an insulated ceiling. With the sun at a low angle you will also get minimal heating benefit on sunny winter days.
If you feel there is no alternative keep the skylight as small as possible (see Australian Standard AS4285 Skylights for sizing guidelines), or use daylight tubes.
A better solution is Daylight Tubes