Fairfax County staff propose looser rules for accessory living units; residents press parking, occupancy and lot‑size concerns

Fairfax County zoning staff presented a draft zoning‑ordinance amendment to expand and clarify rules for accessory living units (ALUs) at a public webinar, proposing to allow more interior and detached units, alter lot‑size thresholds, raise some size limits and remove an added parking‑space requirement outside state‑designated areas.

“An ALU is a secondary dwelling unit in conjunction with and subordinate to a single‑family detached dwelling,” said Casey Judge of the Zoning Administration Division, who led the presentation with Carmen Bishop. Staff showed interior, addition and detached‑over‑garage examples and said the amendment aims to align local rules with the county’s housing action plan and reduce the number of zoning interpretations required.

The draft contains several specific proposals: keep the 1,200‑square‑foot cap for detached ALUs but allow the Board of Zoning Appeals (BZA) to approve larger sizes on a case‑by‑case basis; impose a 35‑foot maximum height for detached ALUs on lots larger than 36,000 square feet while maintaining a 20‑foot cap on smaller lots; raise interior ALU maximums from 800 to 1,200 square feet while preserving a 40% accessory limitation; and adopt a tiered lot‑size approach that allows detached ALUs by right or via administrative approval on lots of 36,000 sq ft or greater, allows them by special permit on lots near 15,036 sq ft, and excludes them on smaller lots.

Staff also recommended removing a separate administrative zoning permit and its associated recordation, renewal and owner‑occupancy requirements so that zoning review would generally occur through the building‑permit process. “If owner occupancy is removed, then the principal dwelling and the ALU could both be rented,” Judge said, adding that existing occupancy rules and the county’s property‑maintenance code would still apply.

The proposed text would also eliminate the ordinance’s requirement that an ALU add one off‑street parking space beyond the existing lot’s requirement. Staff noted new state legislation prevents imposing that extra space in certain designated areas and said accessory uses elsewhere typically do not carry a separate added parking ratio.

Public commenters split on the merits. Cynthia and other residents asked whether removing owner‑occupancy and the extra parking requirement would simply turn ALUs into investor‑driven rental units and increase street parking; staff replied that jurisdictions that eased ALU rules (staff cited Long Beach, Calif.) have not reported widespread parking, overcrowding or trash problems and that parcel‑level parking and septic/sewer impacts are reviewed during building‑permit review. Steve pressed staff to acknowledge that state restrictions apply only to limited areas and that removing the county’s additional parking requirement outside those areas is a policy choice that could worsen parking in many neighborhoods; staff said the recommendation rests on accessory‑use precedent and trying to lower barriers to creating ALUs.

Several residents urged lower lot thresholds (quarter‑acre or smaller) or special‑permit pathways for denser neighborhoods so homeowners could add granny flats for family members. Becca, who cited the county housing needs assessment, said rents in Fairfax have risen sharply and that ALUs are a cost‑effective tool to add housing supply. Others, including Paul, warned that removing owner‑occupancy, renewals and occupancy caps could harm affordability and neighborhood character.

Staff acknowledged multiple concerns, said they are researching school‑enrollment and downstream sewer impacts raised by supervisors, and encouraged continued engagement. Carmen Bishop said the changes are staff‑driven based on outreach and not a special‑interest effort. Staff requested written comments by the end of August as they prepare a staff report for the board’s authorization step; they said public hearings are targeted by the end of the year.

The county has not yet taken formal legislative action; the board will decide whether to schedule public hearings and what final provisions to adopt. Staff materials (white paper and draft text) are posted on the project web page and were linked in the chat during the webinar.