Arguably, the most popular types of housing in the old city of Toronto are the neat, close-set rows of detached and semi-detached houses that date to the great expansion of the 1920s and early ’30s. It’s still a sensible form of high-density housing, but with one major drawback: if your neighbour’s house is only a few feet away, your only natural light comes in through the front and back, making the centre of these houses gloomy. So when renovating or building a new home on these narrow-set lots, bringing in light is always a top priority.