Let there be light

Adding light
A wall of windows and skylights can open up a dark and gloomy living space. Here's a list of "dos" and "don'ts" for adding light.
Skylights
DO pick skylights that open. They're better at venting than windows are. Extra cost: $200 each, or $700 for mechanized ones.
DON'T scatter skylights randomly. To prevent leaks, keep them away from where two parts of the roof meet.
Big windows
DO install big fixed windows on the walls that face your best views.
DON'T neglect to add small windows that open above or below fixed glass.
Window height
DO put windows high on the wall for the best venting and light throughout the room.
DON'T forget that trickier installation hikes the cost of putting windows tight to the ceiling (by $400 each).
Window grouping
DO group several windows together; you'll save on construction costs and have a less obstructed view.
DON'T separate windows with fat supports that ruin your view and run you another $200 per opening.
Window shades
DO keep interior fabrics from fading by installing shades in windows facing east, west or south; built-ins are $100 and up.
DON'T use UV-inhibiting coating, especially near noncoated windows; it gives your glass a tinted or reflective look.