An existing guest space and a proposal to build an accessory dwelling unit raise different questions. Before relying on either in a purchase, identify what exists, what is documented and what still depends on agency review, design work or a property-specific estimate.
Start with the California Department of Housing and Community Development’s current ADU handbook and the Los Angeles Department of Building and Safety ADU resources. State and local requirements evolve; these resources do not establish approval for a particular parcel.
First distinguish existing space from future potential
For an existing structure, record its actual layout, access, utilities and the use described in the listing. Ask which documents relate to that space and whether additional professional or agency clarification is needed. A kitchen, separate entrance or marketing description alone does not answer every approval or use question.
For a proposed ADU, describe the goal before choosing a plan: how the space would be used, its relationship to the main home and the features important to that use. Do not include assumed rental income or construction completion in your purchase plan without investigating the underlying assumptions.
Build a parcel-specific research file
| Research area | Information to collect | Question for the appropriate professional |
|---|---|---|
| Existing improvements | Available plans, permits, inspection information and the layout observed. | Which documents apply to the space and its intended use? |
| Parcel and site | Address, parcel details, access and known site conditions. | What site-specific review is needed before a design is selected? |
| Design and infrastructure | Proposed layout and questions about utilities or site work. | What has been included or excluded from the preliminary concept? |
| Budget and timing | Written scope, estimate date, assumptions and unresolved items. | Which costs and steps remain uncertain? |
Use City Planning’s ZIMAS guidance and LADBS PRISM as starting points for available parcel and building records. Have the relevant agency or qualified professional explain how the information applies to your proposal.
Compare construction proposals on the same scope
Keep design, review, site preparation, utilities, construction and other project questions visible in the budget discussion. Ask each provider to identify assumptions, exclusions and decisions that could change the proposal. A preliminary construction figure is not a complete project budget unless the scope supports that conclusion.
LADBS describes an approved standard-plan program, while noting that a selected plan still needs review for the particular property. Treat a preapproved plan as a starting resource, not a promise that every site or project requirement has been satisfied.
Review intended use beyond the floor plan
Discuss proposed occupancy or rental use with the appropriate planning, insurance, lending and legal professionals. Ask how an existing or proposed unit affects the questions each professional needs to evaluate. Use the investment-property checklist if projected rental use is part of your decision.
For a home with guest or converted space already advertised, the Tarzana accessory-space checklist provides a complementary tour and document framework.
ADU questions buyers often ask
Does a separate building automatically qualify as an ADU?
Do not rely on appearance or the listing label. Ask for the relevant records and confirmation of the use and conditions applicable to the property.
Can I assume the same project as a neighbor?
Investigate the actual parcel, existing improvements and proposed design. Another project does not establish the approvals or costs for yours.
What should I bring to a feasibility conversation?
Bring the address, available records, intended use, a clear description of the proposed space and the budget or timing assumptions that need testing.
Bring the property details to your next conversation
For a home in Encino, Tarzana or Sherman Oaks, share the address or search area, timing and the questions you want to resolve with Romina Ahdoot. Explore the real estate learning center and Romina’s buyer and seller services.
Educational planning information. Confirm current requirements, figures and transaction-specific choices with the appropriate lender, escrow professional, insurer, agency, contractor, attorney or tax adviser. Sources checked November 5, 2026. Romina Ahdoot · Equity Union · DRE #02061222.