Planning & Zoning for Your Rebuild

This section is an overview of the planning processes and policies that shape the rebuilding journey. It is a starting point to help you understand what to expect when beginning the process of rebuilding. Because policies and regulations can change quickly, this page includes links to relevant agencies to find the most up-to-date information.

As you begin the rebuilding process, you will hear a lot about “planning.” Usually done by a local government agency, planning refers to the policies and guidelines that shape how land is used in our communities. Planning can be thought of as the local policies that impact what you can do with your property and how.

Because planning is about local policies, your planning depends on where you live!

Find Your Planning Department
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 LA County Planning Department can be reached by email at [email protected] or by phone at 213-974-6411.
- The City of Los Angeles has a One-Stop Rebuilding Center to guide residents through the rebuilding process and allow them to file all City permits in an expedited and streamlined process. The Center is at 1828 Sawtelle Blvd, Los Angeles, CA 90025.

After you’ve found your planning department, you can begin exploring the specific policies that shape your property. Like many jurisdictions, properties in LA County are categorized into specific “zones,” so your property will have specific “zoning.” Zoning refers to the 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 phrases already, like “residential zoning” or, “single-family zones.”

Your property was likely located in a “Residential Zone” because you were allowed to have a residence/home on it.

Looking Up Your Zoning
You can identify your specific zoning by visiting your local government’s property or zoning look up tool and entering your property address or Parcel Number, found on your tax bill.
- LA County: 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 live in one of the County’s 88 cities, you have to find that city’s specific zoning.
- LA City: 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.

These portals also include links to other resources like the LA Department of Public Works Building Permit Viewer and comprehensive information on your specific property. For LA County, you can navigate to the LA County Assessor Portal and view details on your property, including:

Use Type
Number of Units
Beds/Baths
Building Square Feet
Land Square Feet
Year Built

These details of your property are important to know and to refer to when determining what you can build. For example, you may be able to add more square footage (area) to a new home based on the previous size.

With your planning, zoning, and property information, you have the power to navigate many of the rebuilding policies. To make it easier to rebuild your home, LA City and County have streamlined the process of building back similar to what you initially had. One important note to consider is that while you may be allowed to rebuild larger, additions may trigger tax reassessment. If you have low property taxes because of the length of time you have owned your property, you need to consider the financial implications of major changes.

Please review Your Rebuilding Options to understand some of these tax implications!

Some of the relevant policies you may encounter around what you can rebuild, what steps you have to take, and what it could cost you are outlined below:

Like-for-Like Rebuilds
If you want to rebuild your home like it was, it could be considered a “like-for-like replacement.” For a rebuild to be “like-for-like” it must match the damaged or destroyed structure’s size, location, and use. Limited modifications are allowed if 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 do not trigger a tax reassessment, benefit from expedited permitting and are exempt from current zoning code standards, but still must meet current building, fire, and health and safety code requirements.
Potential Tax Reassessment Triggers
If you increase square footage, the additional portion is reassessed at market value; the original portion retains its prior assessed value. Substantial additions or renovations exceeding 50% of the structure may be considered new construction and fully reassessed.
Additional Structures
For many homeowners wanting to rebuild with more living space, options for renting, or a separate unit to age in place, Accessory Dwelling Units (ADUs) are a great option.
- An 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. For more information, homeowners interested in building ADUs can visit the County’s Planning site.
- 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 unit’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.

There are other planning policies that apply to specific zones, including the ability to subdivide your lot, reconstruction of previous structures that may not be allowed under current planning rules, or new upgrades to be more resilient. These topics should be discussed with a professional architect, contractor, or project manager that can help you navigate the policy implications for your specific project!

Policies can change, so it is important that you bookmark your local planning department website to revisit information regularly!