Building Codes & Habitability — Maryland

City Building Codes — Washington, DC
DC Department of Buildings (DOB) enforces DC Construction Codes (based on 2018 IBC with DC amendments) and DC Property Maintenance Code. Rental registration: DC Rental Accommodations Division (RAD): ALL rental units must be registered (DC Code §42-3502.05); annual fee per unit. DC Rent Control: Rental Housing Act of 1985 (DC Code §42-3501 et seq.): applies to most residential units in DC not built after 1975 or owned by small landlords (4 or fewer units owner-occupied); annual increase capped at CPI + 2% (or 10% max); just cause eviction required. DC Basic Business License: required for all rental housing operations. Heating: Oct 15 through May 15; landlord must maintain 68°F. DC Housing Code (14 DCMR): comprehensive minimum standards for all rental housing including structural, plumbing, mechanical, electrical, and occupancy. DC Office of the Tenant Advocate: provides tenant legal assistance and advocates for habitability. Unique: DC requires landlords to offer lease renewal unless grounds for non-renewal exist.

Building Codes — Delaware (DE) Rental Housing
Adopted code: Delaware State Fire Prevention Regulations and local building codes based on 2018 IBC. Habitability statute: 25 Del. C. §5305 (Residential Landlord-Tenant Code). Heating: Oct 1 through April 30; landlord must maintain 65°F in all habitable rooms. Smoke detectors: required in each sleeping room and on each floor; landlord installs; hardwired with battery backup in new construction; battery acceptable in existing (16 Del. C. §6604). CO detectors: required in all residential units with fuel-burning appliances or attached garage (16 Del. C. §6605). Repair-and-deduct: yes — after written notice and landlord failure within 15 days; cap is $75 per repair. Notable: Delaware preempts local rent control. Wilmington has local housing code enforcement. Delaware's residential landlord-tenant code is one of the more detailed mid-Atlantic codes; landlord must provide written receipts for security deposits and comply with interest requirements.

Building Codes — Alabama (AL) Rental Housing
Adopted code: Alabama Building Code based on 2018 IBC; enforcement is by counties and municipalities. Habitability statute: ALA Code §35-9A-204 (Alabama Uniform Residential Landlord and Tenant Act — URLTA). Heating: landlord must provide working heating equipment; no specific minimum temperature in state law; courts apply 68°F as baseline. Smoke detectors: required in each sleeping room and on each floor (ALA Code §24-9-11); landlord installs; battery or hardwired. CO detectors: no statewide requirement as of 2024. Repair-and-deduct: yes — after written notice and 14-day failure; cap is $200 or half month's rent. Notable: Alabama preempts local rent control. Birmingham and Huntsville have local housing codes. Alabama's URLTA was substantially modernized in 2006 and covers most residential tenancies.

Building Codes — Mississippi (MS) Rental Housing
Adopted code: Mississippi Building Code based on 2018 IBC; enforcement is primarily local. Habitability statute: Miss. Code §89-8-17 (landlord obligations under Landlord and Tenant Act). Heating: landlord must maintain working heating system; no specific minimum temperature. Smoke detectors: required in each sleeping room and on each floor; landlord installs; battery or hardwired (Miss. Code §45-11-201). CO detectors: no statewide requirement. No repair-and-deduct right. Tenant remedy: terminate lease after 30-day written notice and failure to repair. Notable: Mississippi has among the most limited residential tenant protections in the US. Local codes vary widely; rural areas often lack formal code enforcement. Jackson has a local housing code enforcement office.

Building Codes — Washington (WA) Rental Housing
Adopted code: Washington State Building Code based on 2021 IBC/IRC with WA amendments. Habitability statute: RCW 59.18 (Residential Landlord-Tenant Act — RLTA). Heating: landlord must provide heating equipment capable of maintaining 70°F in all inhabited rooms during cold weather — 70°F is stricter than IPMC. Smoke detectors: required in each sleeping room, on each floor, and outside sleeping areas; landlord installs and maintains; if tenant damages detector landlord may charge for replacement. CO detectors: required in all dwellings with fossil fuel appliances or attached garages (RCW 43.44.110). Repair-and-deduct: yes — after 10-day written notice to landlord; cap of $300 or half month's rent (whichever is greater) per repair incident. Seattle Rental Registration and Inspection Ordinance (RRIO): all rental units in Seattle must be registered; periodic inspections required. Notable: WA bans "no-cause" evictions for most tenancies (just cause required after 20+ days); strong anti-retaliation protections.

City Building Codes — Seattle, WA
Seattle Department of Construction and Inspections (SDCI) enforces Seattle Building Code and Seattle Housing and Building Maintenance Code (HBMC). Seattle Rental Registration and Inspection Ordinance (RRIO): ALL rental units in Seattle must be registered; periodic physical inspections required (every 4-6 years depending on building type). Annual registration fee per unit. Heating: WA state requirement of 70°F applies; Seattle requires heat available from heat source within the unit (no central boiler serving multiple tenants without individual controls). CO detectors: RCW 43.44.110 requirement applies; SDCI enforces. Seattle Just Cause Eviction Ordinance: requires specific stated reason (from an enumerated list) for eviction. Tenant relocation assistance: landlords must pay 3 months rent as relocation assistance when displacing tenants for demolition, substantial rehabilitation, or change of use. Seattle Multifamily Housing Code: additional requirements for buildings 5+ units including fire sprinkler systems, accessibility, and green building standards (Seattle Green Building Standard requires most new multi-family to meet LEED or equivalent).

Building Codes — Rhode Island (RI) Rental Housing
Adopted code: Rhode Island State Building Code based on 2018 IBC. Habitability statute: RI Gen. Laws §34-18-22 (Residential Landlord and Tenant Act). Heating: Sept 1 through June 15; landlord must maintain 68°F in all habitable rooms. Smoke detectors: required in each sleeping room and on each floor; landlord installs; hardwired with battery backup required in buildings of more than 2 units; battery in single-family and duplex (RI Gen. Laws §23-28.1-5). CO detectors: required in all residential units with fuel-burning appliances or attached garage (RI Gen. Laws §23-28.1-5.1). Repair-and-deduct: yes — after written notice and landlord failure within 20 days; cap is $125 or one month's rent. Notable: Providence has a rental registration and inspection program. Rhode Island preempts local rent control. RI Department of Health has jurisdiction over minimum housing standards in addition to building code.

City Building Codes — Chicago, IL
Rental registration: All residential rental units in Chicago must be registered with the City; fee varies by unit count. Chicago Residential Landlord and Tenant Ordinance (RLTO, Chicago Mun. Code §5-12): One of the strongest tenant protection ordinances in the US. RLTO applies to most Chicago rentals except owner-occupied buildings with 6 or fewer units. Key RLTO provisions: (1) Landlord must pay interest on security deposit (currently ~1.5% annually). (2) Landlord must provide inventory checklist at start of tenancy. (3) Tenant may withhold up to rent reduction for material non-compliance after 14-day written notice. (4) Repair-and-deduct: up to $500 or half month's rent after 14-day notice and landlord failure. (5) Landlord must give 30-day notice for heat/water/essential service shutoffs. Heating: 68°F required from Oct 1 through June 1 by city ordinance. Chicago Building Department enforces Chicago Building Code (separate from IPMC): includes annual fire inspection for multi-unit buildings. Lead paint: Chicago has own lead ordinance requiring disclosure and testing for pre-1978 units rented to families with children under 6.

Building Codes — Montana (MT) Rental Housing
Adopted code: Montana Building Codes Act based on 2018 IBC; enforcement is local. Habitability statute: MCA §70-24-303 (Montana Residential Landlord and Tenant Act). Heating: Oct 1 through April 30; landlord must maintain 68°F in all habitable rooms. Smoke detectors: required in each sleeping room, outside sleeping areas, and on each floor; landlord installs; battery or hardwired (MCA §50-61-101). CO detectors: required in all residential units with fuel-burning appliances or attached garage (MCA §50-61-102). Repair-and-deduct: yes — after written notice and landlord failure within 14 days; cap is $300 or one month's rent. Notable: Montana preempts local rent control. Billings and Missoula have local housing code enforcement programs. Montana's rental market is tightening rapidly due to population growth; enforcement capacity limited in rural areas.

Building Codes — California (CA) Rental Housing
Adopted code: 2019 IPMC with California amendments; California Building Standards Code (Title 24). Habitability statute: Cal. Civ. Code §1941 (implied warranty of habitability); Cal. Civ. Code §1941.1 (enumerated conditions). Heating: landlord must provide heating to maintain 70°F in all habitable rooms (stricter than IPMC 68°F). SB 721 (2019): mandatory inspection of exterior elevated elements (decks, balconies, walkways) every 6 years for multi-family buildings with 3+ units. Smoke detectors: new construction requires hardwired with battery backup; existing pre-1992 buildings may use battery-only; must be in each bedroom and on each floor. CO detectors: required in all dwelling units with fossil fuel-burning appliances or attached garage (Cal. Health & Safety Code §17926). Repair-and-deduct: yes — tenant may deduct cost of repairs from rent up to one month's rent after landlord fails to repair within 30 days of written notice (Civ. Code §1942). Lead paint: all pre-1978 units must use EPA-certified contractors for any renovation disturbing painted surfaces. Rent control: statewide AB 1482 caps annual rent increases at 5% + CPI (max 10%) for qualifying multifamily buildings 15+ years old. Notable: CA requires landlords to install water-conserving plumbing fixtures when replacing fixtures in pre-2017 buildings.