Massachusetts faces a significant housing shortage that has driven up the cost of housing — median sale price of $900,000 in the Boston area — and rendered the region largely unaffordable. One policy change that is relatively easy to implement could help the housing supply regain some equilibrium: the permitting of accessory dwelling units, or ADUs, sometimes called in-law apartments.
Fewer than half of the cities and towns in Greater Boston allow ADUs that can be rented out. Even communities…