In the United States, secondary suites are technically referred to as accessory dwelling units or ADUs. These ADUs are legally built within or on the same lot as an existing home or apartment. These living spaces provide complete independent living facilities including kitchens, bathrooms, and private entryways. There are, however, certain legal requirements that property owners need to be aware of when it comes to secondary living spaces.
In order to qualify as a finished living space, a basement must meet legal egress requirements for safe escape or easy entry of rescue teams during emergencies. Many home fire deaths occur when residents are attempting to get to the interior exits, but toxic smoke and extremely heats can lead to disorientation during these emergency situations. Legal egress requirements include having windows that adhere to International Residential Code (IRC) criteria, emergency exiting plans, and fire escapes.
Places to safely exit are fundamental for accessory units and each home or apartment needs a minimum of two points of egress. In addition to basement and ADU egress requirements and emergency safety, there are a few additional aspects that property owners need to focus on when it comes to accessory living, including:
- Electrical systems — Since the electrical service needs to be controlled by each resident, it’s important to have a quality and efficient system within the home or apartment. Each unit will need an electrical panel, and all circuits must be fed from their own panels. Additionally, electrical services should not be mixed in order to easily measure how much electricity each unit consumes.
- Internal Energy Conservation Code compliance — All construction projects above a minimal scope — and an accessory unit exceeds the description of minimal scope — must comply with the regulations set by the International Energy Conservation Code. This code sets rules for windows and doors, insulation, heating and cooling, fresh air intake, and many other requirements.
- Plumbing system — Each dwelling unit must have its own means to heat water and distribution. Plus, the unit must have a control valve in order to avoid serious plumbing emergencies. Waste lines cane shared, however, since basement accessory units are separated from the main dwelling, enabling the main waste pipes to be joined.