We have raked ceilings in our new split level extension that follows the fall of the land (and in the rooms that were part of the skillion sections of the old cottage) and I love the sense of space they give and also the fact that the inside reflects what is happening on the outside of the house. We have used ceiling boards (painted white – I didn't want to feel like I was living in a cigar box) both in the old cottage and in the new section and they certainly add an enormous amount of visual interest to the rooms as well. However, I endorse the comments about the added trickiness of light fittings. Pendants with rods are out and pay particular attention to the little rose/canopy thingies that connect pendants to the ceiling – make sure that they sit flush with the ceiling and don't have weird unsightly bits that you can suddenly see because of the angled ceiling. We have successfully used LED downlights with a recessed diffuser and dimmer switches to make sure there is no glare but if the raked angle isn't too extreme they are a definite possibility.

There are so many variables and ways to build things. Building succesfully is very much working well in three dimensions and understanding the structure, and the waterproofing required in three dimensions. Your question suggest that you are only thinking in terms of heights and brick courses, but there are lots of other things happening that would suggest that you get a section of the house and post it with dimensions. Most building professionals work in millimetrres rather than brick coursing. So converting your dimensions to millimetres - 28 courses is 2400mm, which is the minimum height for a habitable room ceiling. Six courses of brickwork is 514mm for the window opening, however your glazed area will be less than this due to the width of the window frame. Your 3 courses of brickwork which is 257mm should be enough for most steel lintels, unless you have a really wide opening for a window? You also need to allow for flashing if the clerestorey is above another roof running into the same wall - if this is the case you may need the full 47 courses. I would be asking your designers why they need 47 courses, as it is a lot higher, and there may be problems with setback issues? Is it a flashing issue? Is it a window opening width and lintel issue. I am afraid you haven't really supplied enough information or images to explain about the clerestorey window so it is impossible to answer precisely. Best of luck, Dr Retro of Dr Retro House Calls and Dr Retro Virtual Visist

thanks all- we in south australia. most homes we have lived in are character homes that have original high ceilings so having the 2400mm ceilings feels more enclosed to us personally. I've researched and hoping we can expose floor joists and line them with gyprock to 'raise' the ceiling height to the lower floor. upstairs we can vault the ceilings and add skylights to open it up

1800mm on a 2740 ceiling height is small. What height, off the floor level, are you starting your 1800mm windows? If you started them at 500mm from floor level, this would give you are nice high window. It would be the cost of the extra wall from floor level. weigh this cost against a 2057mm window. I have 2740mm ceilings and all my living windows are stacker doors at 2340mm. If you are having curtains, you could have your 1800 windows, and have the curtain drop from the cornice of the 2740 ceiling height. This would disguise the low window. But then this also would be an extra cost for the length of the curtain.