an excellent comprehensive beginning, basheva, as expected! can i add that dancers also find it difficult to get worked up about jumping around, when the temperature gets over about a hundred (37 degrees-ish) - but i don't think you'll hit THAT problem too often in camden!
<P>psychologically, i believe a feeling of space and spaciousness is important - light coloured walls and ceiling would be good. windows are good for the same reason, but in the inner city obviously there are privacy concerns, and dancers do get around with very little clothing on, and can be self-conscious - so you will have to balance those needs in your environment. often studios have high windows, so lots of light comes in, but no-one can see in. of course, then you can't see OUT very much.....<P>some studios which have children's classes have a one-way observation window for parents - soundproofed - actually the de valois studio at the royal opera house has this, too (although not for parents, of course, and possibly more as a result of lighting needs in the adjacent corridor, than specifically for observation). if you have one, it's good to have it curtained, so observation can be prevented if desired. same for the mirrors - they should be floor to ceiling (ideally) and be covered with floor to ceiling heavyweight pullback curtains.<P>good even lighting is important in the big space. personally i hate fluorescents......which i have read are not particularly healthy.<P>hopefully lots more people will chime in with more ideas......we love thinking in terms of 'ideals'!