Ever noticed how everyone is suddenly in a better mood when the sun shines? Light and warmth make us feel happier and optimistic, not just because it’s an excuse to eat ice-cream, but because we associate it with growth, sustenance and safety. The same principles apply inside as well as out. Independent studies show that the brighter a home, the happier the occupants. Light, airy spaces cheer us up. Brightness brightens our mood. That’s why we design our homes with larger windows. They let light flood in, filling the rooms with spirit-lifting luminosity. And because they are all well insulated, they trap more of the sun’s heat once inside. Warmer, happier homes? That’s got to be worth looking into.