Step one: the zoning check
Before any design work, confirm the parcel: zoning district, lot size, existing coverage, easements, utility locations, and whether the property sits in a high-fire, flood, historic or coastal overlay. Overlays are the usual source of ugly surprises — a coastal zone parcel can add months and an entirely separate approval track.
This is a records-and-maps exercise that takes hours, not weeks, and it should always precede a design contract.
Setbacks and siting standards
| Standard | Typical requirement |
|---|---|
| Side and rear setback | 4 feet |
| Front setback | Matches the primary dwelling |
| Separation from main house | 6–10 feet, varies locally |
| Height | 16–25 feet depending on type and transit proximity |
| Lot coverage | Cannot be used to block an 800 sq ft unit in CA |
| Fire separation | Rated assemblies within 5 feet of a property line |
What goes in the submittal
- Site plan with dimensioned setbacks, easements and utility runs
- Floor plans, elevations and building sections
- Structural drawings and calculations
- Title 24 energy compliance report
- Drainage and grading plan where slope or impervious coverage triggers it
- Sewer or septic capacity documentation
The four things that get plans rejected
First, an incomplete site plan — missing easements, missing existing structures, unlabeled distances. Second, energy compliance errors, usually a Title 24 report that does not match the window schedule on the drawings. Third, undocumented sewer or septic capacity, especially on older laterals and any septic system. Fourth, fire-rating details missing at walls within five feet of a property line.
Every one of these is a document problem, not a design problem, and every one costs a resubmittal cycle of four to eight weeks. A complete first submittal is the cheapest schedule insurance available.
After the permit issues
Inspections follow the build: foundation and setback verification, underground utilities, framing, rough mechanical-electrical-plumbing, insulation, drywall, and final. Each is scheduled by your builder, and each gates the next phase of work — and, on a construction loan, the next draw. A builder who batches inspections properly saves weeks over one who calls them in reactively.
Final inspection produces the certificate of occupancy. Only then can the unit be legally rented, and only then will an appraiser count it.