Many of the Section 811 (capital advance) housing units developed for the physically and mentally disabled are typically one-story construction that can take full advantage of using solar light tubes (aka Solatube, Velux Sun Tunnels, etc.) for ancillary lighting of hallways, closets, laundry areas, bathrooms, kitchens, etc).
Unlike skylights that can often times be problematic, "light tubes" have minimal roof and ceiling penetrations requiring only an aluminum flashed acrylic dome (typically 12-inch in diameter) on the roof and highly (interior) polished aluminum tubing that gathers and channels natural daylight into the unit via a 10-12-inch diffuser installed at the ceiling.
I installed one in my home and cannot believe the difference it makes on interior illumination - even on cloudy days or at night when the moon is full or waning! The nice feature about a sun tunnel is that it is not prone to excessive heat, humidity and/or condensation like a skylight since the (round) diffuser is sealed at the ceiling and resembles a light fixture lense. I've had it installed for over three years with no problems and am contemplating on installing one or two more since it still amazes me to no end the amount of light brought into the home.
Furthermore - and from a therapeutic perspective - bringing natural daylight into a housing unit developed specifically for the mentally disabled may also benefit the resident by reducing the effects of light deprivation on a persons well being.
The unit(s) can also be installed in various types of subsidized housing for the elderly (202 Capital Advance) to reduce electric cost, as well enhance the lighting and safety of an apartment's interior for a much more comfortable and plesing environment.