Many schools are upgrading to PIR controlled lighting when they have a makeover. If no movement is detected in an area for 10 minutes the lights dim to half power. If there's still no movement for a further 10 minutes, they switch off.
Only seems to cause a problem when they're doing exams and the teacher has nodded off at the front !
Many council properties are adopting similar systems but they are just on or off, no fancy dimming circuits. There is a small "permanently on" set of lights distributed around the place.
If you had them adjusted right you could simulate that car advert where the street lights come on as the car passes then go out again ! It would make the Cardiac Arrest team look very impressive at night
