The LA construction glossary.
Every acronym, ordinance, and code section we cite in the field, in plain English. Bookmark this page — we'll be adding to it monthly.
Permits
- LADBS (LA Department of Building and Safety)The City of Los Angeles agency that issues building permits and conducts inspections.
- ePlanLADBS's fully electronic plan-check portal for residential and commercial permits.
- Ministerial ReviewPermit review based purely on objective standards — no public hearing, no discretion.
- LA City PlanningThe City of LA agency that handles zoning, entitlements, and HPOZ review.
- LADBS (LA Dept. of Building & Safety)The City of LA's plan-check, permit, and inspection authority.
- CEQA (California Environmental Quality Act)State law requiring environmental review of discretionary government actions.
Zoning
- ADU (Accessory Dwelling Unit)A self-contained second home on a residential lot, with its own kitchen, bath, and entrance.
- JADU (Junior Accessory Dwelling Unit)A smaller ADU carved out of the existing house, capped at 500 sqft, with owner-occupancy required.
- HPOZ (Historic Preservation Overlay Zone)City of LA designation that imposes design review on alterations within a historic neighborhood.
- BHO (Baseline Hillside Ordinance)City of LA rules governing residential construction on hillside lots — height, grading, haul routes.
- Coastal Development Permit (CDP)Permit required for construction inside California's Coastal Zone, issued by the city or the California Coastal Commission.
- SetbackMinimum distance a structure must be from a property line.
- FAR (Floor Area Ratio)The ratio of total building floor area to lot size — caps how much you can build.
- BMO (Baseline Mansionization Ordinance)City of LA rules limiting the size of single-family homes in non-hillside R1 zones.
- JADU (Junior Accessory Dwelling Unit)An ADU up to 500 sqft carved out of an existing single-family home.
- AB 68 (Assembly Bill 68)2019 California law that streamlined ADU approvals and removed local barriers.
- AB 10332023 law letting cities opt in to allow ADUs to be sold separately as condos.
- SB 9 (Senate Bill 9)Law allowing duplex conversion and lot splits on most single-family parcels.
- Owner-Occupancy RequirementA city or state rule that the property owner live on-site as a primary residence.
- BHO (Baseline Hillside Ordinance)City of LA ordinance regulating size, grading, and access on hillside lots.
- HPOZ (Historic Preservation Overlay Zone)City of LA designation that adds Historic Board review to exterior changes.
- Coastal Zone (Coastal Development Permit)Coastal Commission jurisdiction requiring an extra permit for development near the coast.
Construction
- Soft-Story RetrofitMandatory seismic strengthening of older multifamily buildings with weak ground floors.
- Soils ReportEngineering study of subsurface soil conditions, required for hillside and certain ADU lots.
- LADWP (LA Department of Water and Power)City of LA's water and electrical utility — handles ADU service connections and meter sets.
- CSLB (Contractors State License Board)California state agency that licenses and regulates construction contractors.
- CSLB (Contractors State License Board)The California agency that licenses, regulates, and disciplines contractors.
- Class B License (General Building Contractor)CSLB license covering general construction requiring 2+ unrelated trades.
- General Contractor (GC)The primary contractor responsible for executing and coordinating the entire project.
- Design-BuildA delivery model where one firm provides both architecture and construction.
- Value Engineering (VE)Substituting equivalent-performance materials or methods to lower cost without losing quality.
- Scope CreepUncontrolled additions to a project's scope after the contract is signed.
- Change OrderA written contract amendment documenting a change in scope, cost, or schedule.
- AllowanceA dollar budget for an undecided selection (tile, fixtures, appliances).
- ContingencyReserved budget for unforeseen conditions discovered after demolition or excavation.
- Soils Report (Geotechnical Report)A licensed engineer's analysis of soil bearing capacity, expansion, and seismic risk.
- Soft-Story RetrofitSeismic strengthening of buildings with a weak ground floor (carports, open garages).
- Prevailing WageGovernment-set hourly wage that public works contractors must pay each trade.
- Mechanics Lien & Lien ReleaseStatutory security a contractor or supplier can record against the property for unpaid work.
- Electrical Panel UpgradeReplacement of the main electrical service panel with higher amperage capacity.
- Heat Pump (HVAC & Water Heating)Electric appliance that moves heat instead of generating it — the 2025 Title 24 baseline.
- Structural Engineer (SE)Licensed engineer who designs the load-bearing system of a building.
- Construction Documents ("Blueprints")The drawing and specification set submitted for permit and used to build.
Finance
- Construction LoanShort-term loan covering construction costs, converted to a permanent mortgage at completion.
- HELOC (Home Equity Line of Credit)Revolving credit line secured by your home's equity — common ADU financing path.
- RenoFi LoanRenovation loan that underwrites based on the home's value AFTER the work is completed.
Code & Law
- AB 682020 California law that streamlined ADU permits — 60-day clock, parking exemptions, ministerial review.
- AB 22212022 amendment that closed loopholes in AB 68 — clarified setbacks, height, and the 60-day clock.
- SB 92021 California law allowing ministerial lot splits and duplexes on most single-family lots.
- SB 12112024 California law expanding ADUs on multifamily lots — up to 8 detached ADUs allowed.
- Title 24California's energy efficiency code — required for all new construction and most additions.
- HERS RatingField verification of energy-efficiency measures required by Title 24.
- VHFHSZ (Very High Fire Hazard Severity Zone)Cal Fire-designated zone requiring ignition-resistant construction (Chapter 7A).
- CBC Chapter 7ACalifornia Building Code chapter setting ignition-resistant construction requirements.
- Defensible SpaceCleared and managed vegetation buffer around structures in fire zones.
- Alquist-Priolo Fault ZoneState-mapped active-fault buffer that prohibits habitable construction over the trace.
- Liquefaction ZoneMapped area where saturated soils can lose strength during an earthquake.
- Title 24 2025 UpdateLatest revision to California's building energy code (effective January 1, 2026).
- EV-Ready / EV-CapablePre-wiring and panel capacity for future electric-vehicle charger installation.
reader notes
About this glossary
How is the glossary organized?
Five buckets: permits, zoning and land-use, construction, finance, and California building code. Each term carries a short plain-English definition, longer body, related-term links, and source citations to the underlying statute or city procedure. Start browsing on the glossary index.
Where do the definitions come from?
Our principal architect, our permit runner, and the project managers who run California builds every week. We cite the underlying Gov Code, LADBS bulletin, or SF DBI procedure when one exists — see also the permit directory for the source portals.
Is this glossary California-specific?
Yes — every term, statute reference, and city procedure is grounded in California law and Greater LA / Bay Area practice. See coverage on the studio pages. Out-of- state readers can use it for orientation but should not assume the rules transfer.
How often is it updated?
Quarterly review with on-demand updates when state law or a major city code changes. Each entry is dated; anything older than 6 months without a review note should be treated with caution and cross-checked against the field journal.
Can I suggest a term that's missing?
Yes — message the studio via the contact page. We add 3–5 new terms a month based on what owners are actually asking about during consultations.
Why are some terms cross-linked inside paragraphs?
Acronyms and overloaded jargon (JADU, Title 24) auto-link to their glossary entry the first time they appear anywhere on the site. Same idea inside field guides and journal posts — every term resolves to its definition.
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