Accessory Dwelling Units

• Author: Tyler Adams
• Pages: 2-6

2 Sustainable Development Code: Climate Change

ACCE SSO RY

DWEL LIN G UNI TS

Tyler Adams (author)

Jonathan Rosenbloom & Christopher Duerksen (editors)

INTRODUCTION

Accessory dwelling units (ADUs) help maximize space in residential dis-

tricts. ADUs are additional living quarters on single-family lots that are

independent of the primary dwelling unit and can go by a variety of names

such as accessory apa rtments, second units, in-law units, laneway houses,

and granny ats.1 ese additional apartments or cottages may or may not

be attached to the existing home and tend to be smaller, with many juris-

dictions having size limitations. ADUs are built with fully-equipped living

quarters, including kitchens and bath s. ADUs are typically owned by the

property owner of the single-family lot and are either rented out or granted

access to another part y depending on the situation and permission pursuant

to the local code.2 While ADUs can take a variet y of forms, they generally

appear in three congurations in relation to the primary dwelling: inter-

nal, attached, and detached. Internal ADUs are integrated into the existing

structure, such as a converted att ic or basement, attached ADUs are built on

as additions to the primary unit, and detached ADUs are built structura lly

separate, such as a converted detached garage.3

ADUs are not a new concept to address aordable housing. In the United

States, ADUs were a very popular housing option in the early nineteenth

century with the expa nsion of cities during industrialization.4 Ho wev er, f ol-

lowing World War II the American shift to suburban-ism led to many leav-

ing the city and seeking out larger single-family lots that were restricted by

Euclidean zoning.5 e rise in housing prices a nd the decrease in the avail-

ability of low-rent units has led many jurisdictions to bring back ADUs as a

form of low impact aordable housing. Even outside the legislative process

communities have been developing programs using ADUs as a way to com-

bat housing shortages and the subsequent rise in homelessness.6