Homeowner Policy & Architecture Glossary

Assessor’s Parcel Number (APN)
An Assessor’s Parcel Number (APN) is the unique number assigned by the city’s tax authorities to identify your property (including land and structures) for record-keeping purposes (LAHD).

Deed
Your deed is a legal document that transfers real estate ownership. To see a sample deed of trust with explanations of relevant elements, visit the LA County Department of Consumer and Business Affairs (DCBA) website.

Documentation / process for ownership
Samples of documentation needed to show or prove ownership can be found with the Los Angeles County Registrar-Recorder/County Clerk.

Fair Market Value
Fair Market Value refers to the assessed value of a property compared with similar properties in the area. It is often calculated by a professional home appraiser.

Heirs property
Heirs property is real estate passed down without a will, leaving ownership divided among multiple heirs while the title remains in the deceased person’s name. Because title is unclear, heirs can’t fully use or borrow against the property and may be ineligible for homeowner benefits (Urban Institute).

Lot / Site
A lot or site is a measured portion or parcel of land considered as a unit having fixed boundaries (LA County Residential Code).

Lot Line
The boundary or lot line separates two adjacent properties. Your lot line or property line is the legal boundary of your property, and setbacks are measured from these lines.

Property Line
See definition for Lot Line.

Site Plan
A drawing showing your property boundaries, existing and proposed structures, setbacks, driveways, trees, and grading.

State Tax Lien
A lien is placed on property for failing to pay state income taxes (LA County Clerk).

Trust Deed
A trust deed is a document that transfers land to a trustee as security for a debt or other obligation (LA County Clerk).

Conditional Use
Conditional uses are those requiring discretionary review to ensure they fit appropriately with existing or allowed uses in the zone. Discretionary review may be required based on unique characteristics like size, technology, equipment, location, traffic impacts, or demand on public services (LA County Planning).

County Assessor’s Portal
The LA County Assessor’s Portal is an online tool that provides detailed property information for parcels within Los Angeles County. It includes data from the Assessor’s current assessment rolls including land use, building characteristics like square footage or year built, a property’s assessed value, historical property values and taxes, and ownership information. The Assessor’s Portal can be accessed here.

Debris Removal
Debris removal refers to the process of removing impacted or hazardous materials from burned sites. In partnership with LA County Public Works, the US Army Corps of Engineers (USACE) conducted the clearing of debris from sites. At this time, you may have opted into debris removal. The opt-in date for debris removal done by the Army Corps of Engineers was April 2025. To confirm the status of removal, visit the interactive webpage. If you opted out of the process, please visit this LA County website to confirm next steps.

Disaster Recovery Ordinance
LA County’s Disaster Recovery Ordinance eases development requirements and allows for rebuilding in impacted Altadena and unincorporated LA County. One specific element of the Ordinance allows for temporary housing and accessory structures on properties that previously had legal housing.

Disaster Recovery Permit
A Disaster Recovery Permit is used for rebuilding projects. These permits have an expiration on January 7, 2030, five years from the initial disaster.

Entitlement
An entitlement (or ‘entitlements’), is the planning approval authorizing a specific land use or permitting the construction, modification, or use of a building (LA City Planning Department).

Floor Area Ratio (FAR)
The floor area ratio (FAR) is the ratio of a building’s gross floor area to the total size of the property on which it is located. The equation for determining the FAR is: gross floor area / total property area (LA City Planning Department).

Habitable Space
Habitable area (or habitable space) is any occupiable area intended for living, sleeping, eating, or cooking. Spaces like bathrooms, closets, hallways, storage rooms, and utility areas are not considered habitable space (CA Residential Code).

Like-for-Like
A like-for-like replacement must match the damaged or destroyed structure’s size, location, and land-use. Limited modifications are allowed as long as they do not increase the floor area, height, or building footprint by more than 10% or 200 SF, whichever is greater. Like-for-like rebuilds are exempt from current zoning code standards, but still must meet current building, fire, and health and safety code requirements. Rebuilding a home to the same size and configuration as the original often speeds up permitting and may allow you to keep your property tax base.

Livable Area
Livable area, also referred to as “gross living area”, is the total finished, conditioned, above-ground living space of a home measured from the exterior walls of a structure. To count toward the livable area, a space must be fully enclosed, meet minimum ceiling height requirements, be accessible from the primary living area, and use the structure’s HVAC system. Basements, garages, unfinished attics, porches, and detached structures do not count towards livable the area.

Non-Conforming
A building or property is non-conforming if its current use doesn’t match the zoning code. Non-conforming can also be used to describe the physical attributes of a building that are no longer code-compliant but that were at the time of construction (LA City Planning Department).

Overlay Zone (Zoning Overlay)
An overlay zone is a layer of supplemental development regulations applied to properties within specific subareas. A zoning overlay acts as a specialized zoning district with its own rules beyond those included in the base zoning. All projects within an overlay must comply with all applicable zoning overlay regulations (LA City Planning).

Plan Check Review
Plan check review is the review of plans, specifications, drawings, and supporting documents by a plan check engineer to verify code compliance before permits are issued (LA DWP).

Plans
Plans refer to design drawings of structures or features. For the permitting process, plans must be drawn by licensed professionals, like architects or engineers. Examples of specific plan types include: structural, architectural, floor plans, site plans, elevations, soils reports, among others.

Planning
“Planning” is the process of organizing and administering the use of land, usually done by the local government agency. Planning departments make policies and guidelines that shape the growth and development of communities. The relevant planning department for most homeowners in Altadena is the LA County Planning Department. If you are unsure of your location, use the LA County Jurisdiction Lookup tool to confirm your applicable planning department. The Planning Department can be reached by email at [email protected] or by phone at 213-974-6411.

Z-Net
Z-Net is an online web-based mapping tool to help residents of unincorporated LA County identify their zoning based on their address. If you are not in unincorporated LA County and live in one of the County’s 88 cities, you have to find that city’s specific zoning. The City of LA version of Z-Net is ZIMAS.

Zone Information and Map Access System (ZIMAS)

The Zone Information and Map Access System (ZIMAS) is a web-based mapping tool that provides planning and zoning information for the City of Los Angeles. It offers parcel-specific information like allowable land use and zoning designations (LA City Planning Department).

Zoning
“Zoning” refers to the specific regulations that govern how you develop your property, what you are allowed to build, and how it needs to be designed. You may be familiar with some zoning terminology, like “residential zoning,”“single-family zones,” or “industrial zones.” Each jurisdiction creates and monitors its own zoning! Your property was likely located in a “Residential Zone” because you were allowed to have a residence on the property. Additional zoning details may include “overlay zone” or be found in a “neighborhood specific plan” (see definitions above)!

Additional Living Expense Coverage
Additional Living Expense (ALE) Coverage – also known as Loss of Use coverage – is an insurance provision that covers the costs you incur when you cannot live at your property. Depending on insurance policy, ALE could include rent at a temporary residence, furniture rentals, or transportation. Homeowners should check their insurance policy to know if coverage is time or amount based. If time-based, ALE coverage is a minimum of 24 months plus additional extensions depending on circumstance. All homeowners should contact their insurance provider to understand limitations on ALE and visit the California Department of Insurance to understand their rights.

Bridge Loan
A bridge loan is a short-term loan that uses your current home’s equity to provide funds for a down payment on a new home. A bridge loan is typically more expensive than a standard mortgage, but offers greater speed and flexibility (HomeLight).

Building Code Upgrades Coverage
Homeowners may have supplemental Building Code Upgrades coverage, which can help pay for upgrades required to comply with current codes, including fire-resistant materials, energy efficiency, and structural improvements.

Direct Costs
Direct costs are expenses that can be tied directly to a specific construction activity, task, or project. They form the core financial components of a construction project and are also sometimes referred to as “project costs” (Deltek).

Extended Replacement Cost Coverage
Homeowners may also have supplemental Extended Replacement Cost coverage, which covers increased costs of construction or labor in post-disaster periods.

Homeowner’s Insurance
Homeowner’s insurance To understand coverage, homeowners should contact their insurance provider and ask for their policy and declarations page. Insurance companies must provide this information for free within 30 days of the request. The California Department of Insurance recommends homeowners ask how much coverage they have (1) to rebuild or repair their home, (2) for their personal belongings, and (3) for living expenses. They should also ask about Extended Replacement Cost, Building Code Upgrade coverages, and how to claim benefits. (California Department of Insurance – Top Ten Tips for Wildfire Claimants)

Loss of Use
See Additional Living Expense Coverage.

Misfortune & Calamity (M&C) Relief Program
This program, administered by the Tax Assessor’s Office, allows homeowners to rebuild while retaining their pre-damage tax base. There are two main standards: 120% Rule for Governor-Declared Disaster Areas and Substantial Equivalence. 120% Rule for Governor-Declared Disaster Areas: If the rebuilt property’s value is within 120% of the pre-damage value, it will not be reassessed, but many homeowners may not qualify due to increased property values and construction costs. Substantial Equivalence: Homeowners retain their pre-damage tax base if the rebuilt structure is substantially equivalent in size and use to the original. Additions exceeding the substantial equivalent, such as a bathroom or an ADU, are considered new construction and may be reassessed separately.

New Construction
Under California property tax law, “new construction” includes major additions to land or buildings, alterations to restore a structure to like-new condition or to change its use, significant improvements that rehabilitate or change how the land is used, and the renovation or replacement of fixtures that effectively makes them new (LA County Assessor).

Property Tax Relief
Homeowners whose property received over $10,000 worth of damage file their paperwork within one year of the fires may be eligible for property tax assessment. More information and copies of the forms can be found on the Assessor’s website.

Proposition 13
Proposition 13 (Prop 13) was passed In 1978 to restrict increases of property taxes. Rather than require reassessment annually, Proposition 13 allows an initial property tax assessment at fair market value and moving forward limits property tax to one percent of that assessed value. Assessed value cannot increase by more than two percent year to year, except if there is a change in ownership, new construction, a decline in value, or is listed as a historical property. For homeowners that have had their property for many years, they likely have experienced the benefits of limited property tax increases compared to the rapid increase in home values in Southern California.

Proposition 19
Proposition 19 (Prop 19) was passed in 2020 to amend state law governing property tax benefits. There is a specific provision on disasters, which allows homeowners who have been impacted by a natural disaster including wildfires, to purchase a replacement home of greater value than their original home and transfer their tax base with an adjustment to account for difference in values.

Rebuild Project Fee Waiver/ Refund Request
Impacted homeowners in unincorporated LA County who are rebuilding may be able to request a waiver or refund of project permit and inspection fees. To be eligible for a waiver, deferral, or refund of fees, a homeowner must have both owned and lived on the property on January 7, 2025. Rental and commercial units are not eligible. To ensure eligibility and review details, visit LA County Recovers’ page on Fee Deferrals & Refunds.

Remodel
A remodel is any construction project that raises the quality or extends the usable life of a property. “Like new” or substantially equivalent renovations involve more substantial structural changes including modifying the layouts of existing spaces, altering the use of a property, or upgrading the capacity of the mechanical, plumbing, or electrical systems. Projects part of normal maintenance like termite treatment, dry rot repairs, or roof replacements are not considered remodels and are therefore not accessible. This also includes cosmetic upgrades like replacing bathroom or kitchen finishes or fixtures (LA County Assessor).

Small Business Administration (SBA) Loan
The Small Business Administration (SBA) Loan Program provides low-interest loans with affordable terms to help homeowners and renters recover and rebuild in federally declared disaster areas. Homeowners can borrow up to $500,000 to repair or rebuild their primary residence, and up to $100,000 to replace damaged personal property. SBA loans cover losses not fully paid by insurance and may include additional funds for mitigation upgrades to protect against future disasters (US Small Business Administration).

Soft Costs
Soft costs are costs that include engineering, architectural, and other professional service expenses incurred before the start of construction (LA DWP).

Accessory Dwelling Unit (ADU)
An Accessory Dwelling Units (ADU) is a permanent livable unit that has a full kitchen and bathroom and is additional to a primary unit or structure. ADUs can be attached, detached, within a main structure, or a conversion of an existing accessory structure like a garage. ADUs in LA County are required to be at least 150 SF with varying maximum SF depending on the type. For more information, homeowners interested in building ADUs can visit the County’s Planning site.

Aesthetic Guidelines
Local design rules that regulate how buildings look (materials, colors, roof forms, or styles) to ensure consistency with neighborhood character.

Allowable Height
An allowable height requirement regulates how tall a building may be, measured either by number of stories or by total height in feet (Abundant Housing LA).

Architectural Program
A list of all the spaces and features you want in your home (e.g., number of bedrooms, size of kitchen, storage needs). This “wish list” guides the design.

As-Builts
As-built drawings are drawings that show what was actually built, which may differ from original plans. Often needed if portions of a home survived the fire, revised plan sets prepared after construction is completed that documents changes made during the construction process that were not originally included in the approved plans or specifications (LA DWP).

Basement/Foundation Plan
A drawing showing the structure that supports the home. Important if you are rebuilding a basement or adding a new level.

Buildable Area
The buildable area is the portion of a lot where the primary structure may be constructed and excludes the portions of the lot reserved for required yards, setbacks, and areas limited to accessory uses (City of LA Planning Code).

Building Code
A set of state and county rules that ensure safety (fire resistance, structural strength, energy efficiency, etc.). Your new home must comply with current codes.

Building Envelope
A building’s envelope includes exterior elements, (walls, windows, doors, roof) that protect the interior from weather. Materials matter for fire resistance and energy performance. It includes both conditioned and unconditioned spaces.

Building Footprint
The area of the home that touches the ground. Changing the footprint may trigger new reviews, if your project is considered a like-to-like or longer permitting timelines.

Building Permit
A permit is a legal document issued by the Building Official authorizing construction and serves as a record showing a given project met current code requirements and was built according to approved plans and specifications (LA DWP).

Dwelling Unit
A dwelling unit is one or more habitable rooms designed for one family to live and sleep in, with only one kitchen. This includes mobilehome living areas designed for one family with facilities for living, sleeping, cooking, eating, and sanitation; and 2) any sleeping room that has a bar sink or utility outlets intended for cooking, except hotel guest rooms or suites approved by Conditional Use Permit (CUP) (LA County Planning Department).

Easement
An easement is the granting of a right to use another person’s land, either for benefit of adjoining property, such as a right-of-way, or “in gross” such as an easement for a public utility (LA County Clerk).

Egress
Safe exits from a home. Bedrooms must have emergency escape windows or doors that meet code.

Electrical Code
The LA County Electrical Code (Title 27) (LACEC) regulates the installation, alteration, reconstruction, and repair of electrical wiring, devices, appliances, and equipment in or on any building, structure, or property (LA DWP).

Elevation (Architectural Elevation)
A drawing that shows the outside face of your building (front, rear, sides). Useful for visualizing height, windows, and materials.

Energy Code / Title 24
California’s energy efficiency standards. Reconstruction must meet these requirements.

Floor Area Ratio (FAR)
A planning rule that compares the size of your home to the size of your lot. Helps determine how large you can build.

Geotechnical Report
A geotechnical report, also sometimes referred to as a “soils report”, is prepared by a soils / geotechnical engineer and describes the site’s ability to provide stable ground for construction. It outlines the site investigation, evaluation, design recommendations, testing procedures, and required inspections (LA DWP).

Junior Accessory Dwelling Unit (JADU)
Similar to an ADU, a Junior Accessory Dwelling Unit (JADU) is a residential space within the primary structure that has its own entrance and kitchen facilities. It does not need to include a separate bathroom, but there must be access to the primary’s bathroom. Different from ADUs, JADUs are considered part of the main structure, must be 500 SF or smaller, and the owners must reside on-site.

LA County Code Amendments
The County adopts more restrictive building standards when needed due to local climate, geology, or topography (LA DWP).

LA County Residential Building Code
The LA County Residential Building Code (Title 30) (LACRBC) applies to the construction, alteration, repair, relocation, and use of detached one- and two-family homes and townhouses up to three stories, along with their accessory structures (LA DWP).

Mechanical Code
LA County Mechanical Code (Title 29) (LACMC) covers the installation, alteration, repair, and maintenance of heating, ventilation, cooling, refrigeration systems, incinerators, and other heat-producing appliances. The LACMC applies to the construction, alteration, movement, enlargement, repair, and use of detached one- and two-family dwellings and townhouses up to three stories, along with their accessory structures (LA DWP).

Non-Conforming
A building or property’s use that doesn’t currently conform to current zoning code is described as non-conforming. Non-conforming can also be used to describe the physical attributes of a building that are no longer code-compliant but that were at the time of construction (LA City Planning Department).

Non-Habitable Area
Non-habitable area refers to the parts of a dwelling that do not meet the standards for occupancy. This includes areas like bathrooms, laundry rooms, hallways, stairways, closets, and other service or maintenance areas.

Parking Requirements
Parking requirements specify the number of parking spaces a project must provide. For residential uses, the requirement depends on the number of units; for commercial and industrial uses, it’s based on the building’s square footage (Abundant Housing LA).

Plumbing Code
The LA County Plumbing Code (Title 28) (LACPC) covers the construction, alteration, relocation, removal, repair, and use of gas piping, plumbing, drainage systems, house sewers, and private sewage disposal systems (LA DWP).

Pre-Approved Standard Plans
Pre-approved standard plans are designed plans that have gone through part of the planning and permitting process. The benefits include a shortened and predictable review timeframe and process and reduced design cost. Homeowners still have to work with a design professional, and irregular lots may not be suitable for plans.

SB 9
Senate Bill 9 (SB 9) is a state law that has two provisions meant to increase infill housing in Los Angeles. The first provision allows two housing units to be built on single-family zoned lots. The second provision allows for an urban lot split of a single-family zoned lot. Under SB 9, a single-family lot can be split with each new lot supporting two units (a total of four housing units). In July, 2025, LA County gained authority to suspend SB 9 without review in Very High Fire Hazard Severity Zones (VHFHSZ).

Scope of Work (SOW)
A detailed description of what is included in your project; essential for accurate contractor bids and contract pricing.

Setback
Setbacks are the required distances between your building and property lines. Fire zones may have special setback rules.There are three different kinds of setbacks. There is the front yard setback, rear yard setback, and the side yard setback. The setbacks are offset by a specified distance from the property line. Typically, the setbacks act as a buffer space where structures are not erected. However, certain kinds of building elements can extend into the setbacks. Fire zones may have special setback rules.To check the setbacks for a lot, the zone with its corresponding development standards should be reviewed. For instances where structures are erected within the setbacks, see ‘Non-Conforming.’

Urban Lot Split
An Urban Lot Split is a process where a single-family zoned lot can be split into two lots. The resulting lots must be relatively equal in size and at least 1,200 SF. Urban Lot Splits are not currently allowed by-right in “Very High Fire Hazard Severity Zone” areas in boundaries of the Eaton and Palisades fires.

Very High Fire Hazard Severity Zones (VHFHSZ)
CAL FIRE maps out areas of increased fire risk. Very High Fire Hazard Severity Zones (VHFHSZ) are areas with extreme wildfire risk that require stricter building codes and land management. Visit CAL FIRE’s website to map your property.

Building Inspector
A building inspector is a trained and certified government employee responsible for performing inspections and making professional judgments on building code compliance (LA DWP).

Certificate of Occupancy (CofO)
A certificate of occupancy allows for occupation and is issued after a building passes final inspection and receives all necessary agency approvals. The CofO will include the permit number, side address, owner’s name and address, a description of the approved work, a statement confirming compliance with the applicable building code, and the name of the building official (LA DWP).

Construction Documents (CDs)
Detailed drawings and specifications used for permitting and construction. These come after design development and are required by contractors.

Contractor Bid
A cost proposal prepared by a contractor based on your plans. Often includes labor, materials, and timeline.

Covenants, Conditions & Restrictions (CC&Rs)
Rules set by HOAs or local authorities that may affect what you can build.

Design Development (DD)
A stage of design where concepts become more detailed. Rooms, windows, materials, and layouts are refined before construction documents begin.

Drainage Plan
A civil engineering drawing showing how water flows on your site.This plan is critical in hillside or post-fire environments.

Final
Final occurs when the work is completed and has passed inspection. An inspector will finalize the project by singing and dating the permit and job card, and issuing a Certificate of Occupancy (LA DWP).

Fire-Resistant Construction
Materials and design strategies that reduce fire risk; such as Class A roofs, ignition-resistant siding, tempered windows, and ember-resistant vents.

Floor Area Ratio (FAR)
A planning rule that compares the size of your home to the size of your lot. Helps determine how large you can build.

Footings
Concrete bases that support foundation walls. May need upgrades if planning for a future second story.

Geotechnical Report
A soil analysis required on some lots, particularly hillside or high-risk fire areas, to determine foundation needs.

Grade
The ground level. Changes to grade can affect drainage, retaining walls, and permitting.

Hook-Ups
Utility hook-ups are the connections that link your home to water, sewer, and electrical systems. Licensed plumbers and electricians complete these connections, which must pass inspection before activation.

Hook-up /connection fees are charges that allow a utility to fully recover the cost of connecting a new customer to an existing system. They are based on standard connection and excavation costs and typically cover installation of the service line, meter, and related labor (CA PUC).

HVAC
Heating, ventilation, and air conditioning systems. New codes may require upgrades or new types of systems.

Ignition-Resistant Materials
Approved materials designed to resist catching fire from embers or radiant heat.

Inspector
A city or county official who checks construction for compliance with building codes and approved plans.

Mechanical, Electrical, Plumbing (MEP)
Three engineering disciplines needed for full construction drawings; HVAC system design, electrical layouts, and plumbing routing.

Mitigation Measures
Required actions to reduce risks related to fire, slope, drainage, or environmental impacts.

Plan Set
A complete set of drawings used for submittal to planning and building departments.

Property Tax Reassessment
A process that determines whether your rebuilt home maintains its original tax base or receives a new, possibly higher assessment.

Retaining Wall
A structure that holds back soil. Common in hillside terrain or lots altered after fire.

Right-of-Way (ROW)
Land owned by the public (street, sidewalk) that may limit where you can build.

Title 22
LA County zoning and planning regulations that may apply alongside Community Standards District (CSD) requirements.

Topographic Survey
A map prepared by a licensed surveyor showing elevations, slopes, and physical features of your lot; critical in fire-impacted terrain.

Wildland-Urban Interface (WUI)
High-risk fire zone areas where stricter building requirements apply.

Window Schedule
A document listing all windows, sizes, materials, and fire or energy ratings.