HOMEOWNER PLANNING WORKSPACE
California ADU Planning Tools & Worksheets
Organize an ADU idea into a practical planning file. Start with feasibility, organize the property questions, compare realistic options, and prepare better questions before paying for design or construction.
CHOOSE YOUR STARTING POINT
What are you trying to decide today?
Which agency and rules apply?
Identify the permitting jurisdiction and gather official sources before choosing a design.
Read the rules and permits guide → 02Does my property look feasible?
Build a property file covering jurisdiction, dimensions, access, utilities, hazards, and budget evidence.
Screen the property → 03Which ADU type should I investigate?
Compare detached, attached, conversion, above-garage, interior, prefab, and modular approaches.
Compare ADU types → 04What should the complete project include?
Move beyond a cost-per-square-foot headline and identify design, site, utilities, fees, construction, and contingency.
Review cost drivers →PLANNING RESOURCES
Use the available worksheets and budget calculator.
The nationwide property checker and state-rules lookup have been retired. A California-specific replacement is planned but is not available yet.
For now, use the planning guide and the resources below. No worksheet or calculator provides permit approval.
AVAILABLE WORKSHEETS AND CALCULATOR
Carry your evidence into the next conversation.
Scenario budget calculator
Arithmetic on your inputs; prefilled values are fictional. Missing or invalid inputs withhold the total.
Budget and unknown-cost worksheet
Record scope, amounts, sources and unresolved costs. No automatic calculation.
California permit worksheet
Track your agency checklist, notices, corrections and approval records.
Contractor evidence worksheet
Record verified evidence and unresolved issues, without a performance score.
Bid-comparison guide and PDF
Compare included scope, allowances, exclusions and unknowns. The guide links to its fillable PDF.
Construction meeting worksheet
Track decisions, inspections, changes, responsible people and next actions.
Browser worksheets: type into the cells, then Print → Save as PDF before leaving or reloading. Entries do not persist. A completed checklist is not permit or inspection approval.
THE PLANNING ORDER
Use tools in the sequence that prevents expensive assumptions.
- 01
Identify the authority
Confirm the city or county that controls planning and building review for the property.
- 02
Verify the rule layers
Separate state baseline rules, local standards, overlays, recorded constraints, and utility requirements.
- 03
Document the property
Collect parcel dimensions, structures, access, utilities, slope, drainage, hazards, and existing records.
- 04
Compare realistic configurations
Shortlist one or two ADU types that fit the property and the intended resident.
- 05
Build a complete budget
Include design, studies, approvals, site work, utilities, construction, finishes, financing, and contingency.
- 06
Prepare for professional proposals
Give designers and contractors the same project facts so their scopes can be compared consistently.
TOOLS BY PROJECT STAGE
A connected workspace—not isolated calculators.
AVAILABLE
California permit worksheet
Track agency requirements, submissions and correction responses.
Open the worksheet →AVAILABLE
Property Feasibility File
Collect the evidence needed for the first planning conversation.
Build the file →AVAILABLE
ADU Type Comparison
Narrow detached, attached, conversion, and factory-built options.
Compare types →AVAILABLE
ADU Budget Worksheet
Record costs, scope, evidence and unresolved items, then print or save a PDF.
Open the budget worksheet →AVAILABLE
California ADU ROI Calculator
Test rent, vacancy, operating costs, financing and break-even cash flow with visible assumptions and a ±10% sensitivity matrix.
Open the ROI calculator →AVAILABLE
Contractor Bid Comparison
Compare scope and allowances with a worked example and free fillable PDF.
Compare bids and download the checklist →AVAILABLE
Permit and Correction Worksheet
Record your jurisdiction’s requirements and plan-check responses. This is a worksheet, not an automatic generator.
Open the permit worksheet →PLANNED — NOT AVAILABLE
Site-Fit Worksheet
Organize dimensions, setbacks, access, utilities, hazards, and unresolved property constraints.
HOW WE BUILD TOOLS
Assumptions should be visible—and uncertainty should stay visible.
Evidence before output
Regulatory results link to official material and show what still needs local verification.
Ranges before false precision
Cost and return estimates should expose assumptions rather than imply a guaranteed number.
Property facts before recommendations
A result is only as useful as the address, site conditions, scope, and constraints entered.
Next questions, not just answers
Every tool should leave the homeowner with a clear verification or planning action.
BEFORE USING A RESULT
Know what an early planning tool cannot decide.
It cannot approve the project.
Only the authority having jurisdiction can determine how current rules apply to a specific parcel and proposal.
It cannot inspect the site.
Surveys, records, utilities, soil, drainage, hazards, and existing conditions may materially change feasibility.
It cannot replace a complete proposal.
Designers, engineers, contractors, lenders, tax advisers, and insurers address different parts of the decision.
BUILD YOUR NEXT STEP
Leave with a better planning file than you arrived with.
EDITORIAL AND DATA STANDARD
Useful outputs require traceable inputs.
We prioritize primary government and institutional sources for rules, show review dates where practical, distinguish state guidance from local approval, and avoid presenting estimates as guarantees. Tool outputs are general educational planning aids, not legal, design, engineering, tax, lending, insurance, or investment advice.
Read the Editorial & Source Policy and verify project-specific information with the responsible agencies and qualified professionals.