LA Real Estate Glossary: From the 405 to Mello-Roos

Every city has its own vocabulary, and LA's mixes freeway slang, weather words and a long list of real estate acronyms. Here are the terms you'll hear most when you move here and buy a home, and what each one means.

Tax, legal and insurance terms below are general descriptions, not advice. Rules change, so verify details for any specific property with the right professional.

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• The 405 (and "the" freeways). Southern Californians put "the" in front of freeway numbers: the 405, the 10, the 101, the 110. The 405 runs north and south along the Westside, through the Sepulveda Pass into the Valley, and is famous for its traffic.

A

• ADU and JADU. An accessory dwelling unit is a second home on a single-family lot, like a backyard cottage or a converted garage. A junior ADU is a smaller unit created within the main house. State law generally allows them across California, but each city sets its own standards.
• Alquist-Priolo zone. An earthquake fault zone mapped by the state around active faults. If a property is in one, it should be noted in the Natural Hazard Disclosure report, and building near the fault can require geologic studies.

B

• BMO. The Baseline Mansionization Ordinance, a City of LA rule that limits how large a house can be relative to its lot in many flatland single-family areas.
• Bolting and bracing. A seismic retrofit for older wood-frame homes on raised foundations: bolting the house to its foundation and bracing the short "cripple" walls in the crawl space. The state's Earthquake Brace + Bolt program has offered grants of up to $3,000 in eligible zip codes for homes built before 1980 (2025 program rules).
• Brush clearance. Annual requirements to cut back vegetation around homes in and near fire zones. In the City of LA, the Fire Department sets the rules and inspects each year (LAFD brush clearance).

C

• Canyon. In LA, both a landform and an address: Laurel Canyon, Benedict Canyon, Coldwater Canyon and Topanga Canyon are winding roads through the hills, lined with homes on wooded or terraced lots.
• Case Study House. A series of experimental modern homes sponsored by Arts and Architecture magazine from 1945 to 1966, including Pierre Koenig's Stahl House in the Hollywood Hills and the Eames House in Pacific Palisades. See the Case Study Houses of Los Angeles.
• Coastal zone. Land near the coast where the California Coastal Act applies. Many projects there need a coastal development permit, which can add review time in places like Venice and Malibu.
• Contingency periods. The windows in a purchase contract when a buyer can investigate the property, confirm the appraisal and finalize the loan, and cancel if needed. The standard California contract commonly defaults to 17 days for investigations, and all of them are negotiable.
• Craftsman. The early 1900s Arts and Crafts house: low-pitched roofs, deep eaves, exposed rafters, wide porches and lots of wood. Pasadena, with Greene and Greene's 1908 Gamble House, is the best-known place to see them.

D

• Documentary transfer tax. A tax on the sale of real estate. LA County charges $1.10 per $1,000 of value, and some cities add their own, including the City of LA. Who pays is negotiated, though sellers commonly pay here.

E

• Earthquake insurance. Standard homeowners policies generally exclude earthquake damage. Separate coverage is available, including through the California Earthquake Authority, and it's a choice each owner weighs.
• Eastside. Traditionally the neighborhoods east of the LA River, like Boyle Heights and Lincoln Heights. In everyday use, many people also mean Silver Lake, Echo Park, Los Feliz, Highland Park and Eagle Rock. See Westside vs Eastside.
• Escrow. A neutral third party that holds the money and documents until every condition of the sale is met, then closes the transaction. Always confirm wiring instructions by phone at a number you already know.

F

• FAIR Plan. California's insurer of last resort. Its dwelling policy covers named perils such as fire, lightning, internal explosion and smoke, and owners often add a separate "difference in conditions" policy for other coverage (California FAIR Plan).
• Fire Hazard Severity Zone. State maps rating fire hazard as moderate, high or very high. A Very High Fire Hazard Severity Zone brings stricter building standards and brush clearance rules, and can affect insurance. Look up any address with the State Fire Marshal.
• The Flats. The level, gridded part of an area below the hills, most famously the Beverly Hills Flats between Sunset and Santa Monica Boulevards.

H

• Hillside ordinance (BHO). The City of LA's Baseline Hillside Ordinance, which limits house size, height and grading on hillside lots based on lot size and slope. It matters a lot if you plan to add on or rebuild.
• Historic-Cultural Monument. A City of LA landmark designation for buildings and sites of historic or architectural significance. Changes to a designated property generally go through review by the city's Office of Historic Resources.
• Homeowners' exemption. A California property tax exemption that reduces the assessed value of an owner's primary residence by $7,000. It generally applies only if you file for it.
• HPOZ. A Historic Preservation Overlay Zone, the City of LA's version of a historic district. Exterior changes visible from the street generally need design review. Hancock Park and parts of Highland Park are examples.

I

• Impound account. An account your lender may use to collect property taxes and insurance with your monthly payment and pay them for you. Supplemental tax bills are often mailed to the owner instead.
• Incorporated vs unincorporated. An incorporated area is part of a city, like Beverly Hills or Culver City. An unincorporated area, like Marina del Rey, is governed directly by LA County. See LA's many cities.

M

• Marine layer. The cool, low cloud deck that forms over the ocean and pushes inland, especially overnight and in the morning. It keeps the coast mild and usually burns off by afternoon farther inland. See LA's microclimates.
• May Gray and June Gloom. Nicknames for the late spring and early summer stretch when the marine layer is most persistent, especially near the coast. See June Gloom explained.
• Measure ULA. A City of LA transfer tax on higher-priced sales, sometimes called the "mansion tax." For sales closing after June 30, 2026, it is generally 4% above $5.4 million and 5.5% at $10.9 million or more, with thresholds adjusted each July (Hanson Bridgett, August 2026).
• Mello-Roos (CFD). A special tax levied by a Community Facilities District, usually to fund roads, parks or other infrastructure in newer developments. It shows up as a separate line on the tax bill and should be disclosed by the seller.
• Metro lines. LA's rail lines go by letters and colors. The A Line runs from Long Beach through Downtown to the San Gabriel Valley, the B Line from Union Station through Hollywood to North Hollywood, the C Line along the 105, the D Line under Wilshire Boulevard (extended to La Cienega in May 2026), the E Line from Downtown to Santa Monica and East LA, and the K Line along Crenshaw through Inglewood.
• Mid-century modern. Post-war architecture with post-and-beam framing, flat or low roofs and walls of glass, found from the Hollywood Hills to the Valley. See mid-century modern homes.
• Mills Act. A California program that lets owners of qualifying historic properties enter a contract with their city for potentially lower property taxes, in exchange for preserving and maintaining the building. Each city runs its own program.

N

• NHD report. The Natural Hazard Disclosure report sellers generally provide, showing whether a property is in mapped flood, fire, earthquake fault or seismic hazard zones. Read it early in escrow.

P

• Pad. The flat, buildable part of a hillside lot, often graded decades ago. A "big pad" means more usable flat land for a house, yard and pool, as in Trousdale Estates.
• Prop 13. The 1978 measure that generally sets a property's assessed value at its purchase price, limits the base tax rate to 1% and caps yearly increases in assessed value at 2%. See property taxes after you buy.
• Prop 19. A 2020 measure that, in general, lets certain homeowners (including those 55 and over and victims of wildfire or natural disaster) carry their assessed value to a replacement home in California, and narrowed the tax break for transfers from parents to heirs. The details are technical, so ask a tax professional.

R

• Red flag parking. On some narrow hillside streets in the City of LA's very high fire zones, posted signs prohibit parking during Red Flag Warnings so fire engines can get through.
• RSO. The City of LA's Rent Stabilization Ordinance, which generally covers rental units in buildings built on or before October 1, 1978, and limits annual rent increases and evictions (LA Housing Department).

S

• Santa Ana winds. Hot, dry winds that blow from the deserts toward the coast, most often in fall and winter. They bring warm, clear days and raise fire danger.
• Sewer lateral. The pipe running from the house to the city sewer. Many older LA homes have clay pipes, so a camera inspection is a common part of buyer inspections.
• SigAlert. A traffic alert for any unplanned event that closes one lane for 30 minutes or more, as the California Highway Patrol defines it (CHP). It's named for Loyd Sigmon, who created the radio alert system in the 1950s.
• Soft-story retrofit. Seismic strengthening for wood-frame apartment buildings with a weak ground floor, often tuck-under parking. The City of LA requires it for many older buildings of this type.
• South Bay. The coastal cities south of LAX, like Manhattan Beach, Hermosa Beach, Redondo Beach and Torrance, each its own city.
• Spanish Colonial Revival. White stucco, red clay tile roofs, arched windows and courtyards, the signature LA style of the 1920s. See Spanish homes in LA.
• Supplemental tax bill. A one-time bill (sometimes two) that covers the difference between the previous owner's assessed value and yours for the rest of the tax year. It can arrive months after closing.

T

• TDS and SPQ. Two standard California seller disclosures: the Transfer Disclosure Statement, a state form about the property's condition, and the Seller Property Questionnaire, which asks about a longer list of specific items. Read both closely.

V

• The Valley. Short for the San Fernando Valley, north of the Santa Monica Mountains. Much of it is in the City of LA, including Studio City, Sherman Oaks and Encino, with warmer summers than the coast.
• View lot. A lot, usually in the hills, positioned for a city, canyon or ocean view. Views can be protected by local rules in some places and not in others, so ask before you count on one staying.

W

• Westside. Generally the area from around Beverly Hills west to the ocean, including Brentwood, Westwood, Mar Vista, Venice and Santa Monica. There's no official boundary.

Z

• Zone 0. The first five feet around a home, where California has been developing ember-resistant rules for homes in fire zones. Timing and details have been changing, so check what's in effect for a specific address.