Hot compost works in the dark as it is the thermophilic bacteria and not sun exposure that make it hot. Keep the compost away from your house if your house is wood! <- just sayin'
Hostas grow in the shade. Edible shoots from what I've heard. Might be a good place for a summer greens (which tend to bolt in full sun in mid summer).
A permanent ladder to your roof? Fire escape?
Insulated above ground or below grade root celler?
Cold koi pond?
Meditation space? Chill Zone?
"Never doubt that a small group of thoughtful, committed citizens can change the world; indeed, it's the only thing that ever has."-Margaret Mead "The only thing worse than being blind, is having sight but no vision."-Helen Keller