This renovation to a prototypical Toronto semi-detached home makes the most of a compact, urban property. Several strategies to maximize tight spaces extend the boundaries of the house. Opening up the main level and adding an oversized sliding door to the backyard fills the living spaces with light and air while extending the house visually to the outdoors during the cooler months and physically in the summer. Custom built-in millwork optimizes small spaces by adding storage while doubling as furniture, and the new finished basement provides overflow space for guests and active kids.