ADU Pass
Juneau City and Borough
ADU Pass helps homeowners in Juneau City and Borough, Alaska navigate the permit paperwork for building an accessory dwelling unit. We cover 2 cities and 4 ZIP codes in this county.
Map
County ADU details
County ADU ordinance
The City and Borough of Juneau (CBJ) is a unified home-rule consolidated city-borough (Alaska's equivalent of a consolidated city-county; ~32,000 residents; the state capital, encompassing downtown Juneau, Douglas Island, the Mendenhall Valley, and roughly 3,255 sq mi of borough land most of which is roadless wilderness). Alaska has no statewide ADU preemption — Alaska's stateAduLaw is netEffect 'no-statewide-law' — and zoning is exercised by Alaska's home-rule and first-class boroughs (those that have organized) and individual home-rule cities. CBJ regulates accessory apartments and accessory dwellings through CBJ Code Title 49 (Land Use Code), Chapter 49.25 (Definitions) and Chapter 49.50 (Use Tables). 'Accessory apartments' are permitted by right in most residential districts (D-1, D-3, D-5, D-10, D-15) subject to maximum size (typically 850 sq ft or 35% of principal dwelling), one-per-lot limit, and parking. Detached ADUs ('accessory dwellings') are conditionally permitted with somewhat tighter standards. The Juneau Assembly amended Title 49 in 2022-2024 to expand accessory apartment allowances as part of its housing-supply response to chronic state-capital housing shortage.
County assessor
Assessment policy: CBJ Assessor's Office assesses real and personal property under Alaska Statutes Title 29 Chapter 45 (Property Tax). New ADU construction is reassessed at full and true value as of January 1 following completion. Alaska has no constitutional assessment growth cap, but the senior citizen exemption (AS 29.45.030(e)) and disabled veteran exemption ($150,000 of value off the homestead) are administered locally. CBJ levies separate areawide and service-area mill rates; the Mendenhall Valley and downtown service areas have higher combined rates than roadless borough territory.
County overlays (3)
Known county issues (3)
- other — Strong demand-side ADU economics partially offset by elevated construction costs (~$400-$600/sf typical for ADU-grade construction in Juneau, vs ~$250-$350/sf in lower-cost continental US markets).
- other — ADU siting along the Mendenhall River is constrained by both FEMA SFHA rules and CBJ's enhanced GLOF overlay; some parcels effectively cannot host new ADUs.
- other — Several downtown and Thane Road parcels cannot host new-construction ADUs regardless of zoning allowance; the avalanche overlay is an absolute prohibition in red zones.
Alaska state — ADU law and programs
State financing programs
Alaska does not operate an ADU-specific statewide loan or grant program. The Alaska Housing Finance Corporation (AHFC) is the state's housing finance agency and administers a broad portfolio of mortgage products, multifamily-development financing, and grant programs. None target ADU construction directly, but several can be used to fund ADU-bearing properties or ADU-adjacent housing supply. The Lands to Housing Catalyst (launched 2025-2026) makes state-controlled land available to homebuilders in the Mat-Su Borough and Fairbanks North Star Borough, including for projects that may include ADUs.
State housing programs
Alaska's statewide ADU-relevant programs are advisory and capacity-building rather than mandatory. The Alaska Municipal League published the 'AkDU's and Don'ts' brochure (2023) as a model-ordinance and best-practices guide for boroughs and cities considering ADU-friendly zoning amendments. The Alaska Housing Finance Corporation's Innovative Housing Initiative supports prefabricated and panelized residential construction methods that include ADU-scale units. Neither is a preemption mandate; both rely on local adoption. No statewide pre-approved ADU plan catalog or impact-fee waiver statute exists.
Federal (United States) — ADU-relevant rules and programs
Federal ADU law
The United States has no federal statute that directly regulates accessory dwelling unit entitlement or design. Land-use authority over ADUs resides with states and local governments under the traditional police power. Federal engagement is limited to financing (Fannie/Freddie/FHA/VA/USDA), flood insurance (FEMA/NFIP), and discretionary housing programs (HUD), which are recorded in sibling sections of this file.
Federal financing programs
Federal housing-finance agencies and GSEs set nationwide underwriting rules that govern whether an ADU can be financed, appraised, and counted toward mortgage qualifying income. The relevant actors are Fannie Mae, Freddie Mac, FHA (HUD), VA, and USDA Rural Development.
Federal tax credits
There is no ADU-specific federal tax credit. ADUs may incidentally qualify for existing federal energy-efficiency and clean-energy tax credits when the ADU construction includes qualifying measures.
Federal housing programs
HUD administers several discretionary programs that can fund ADU-related activity at the grantee's election, but none is an ADU-specific program.