• Detached ADU: in a compliant ordinance framework, the maximum unit size is commonly up to 1,200 sq ft.
• Attached ADU: commonly up to 50% of the existing primary dwelling floor area, with a cap often referenced at 1,200 sq ft, and the state also provides an 800 sq ft streamlined allowance under certain conditions.
• JADU: maximum 500 sq ft.

A JADU uses an efficiency kitchen approach rather than a full standard kitchen layout. The exact configuration can vary, but the intent is a compact kitchen sized appropriately for the unit. 

• A common statewide baseline for new detached ADUs is 4-foot side and rear setbacks. Front and street-side setbacks are often handled locally.
• Zero setback situations: in many cases, conversions of existing structures can be allowed even if the structure is already built close to, or on, a property line. This is one reason garage conversions can be powerful on tight lots.

Height limits vary by jurisdiction and zone. Some areas use baseline limits (and allow more near transit), but you should confirm the exact rule for the address. 

Parking is often not required under common exemptions, especially for conversions or when the property is near transit. Parking rules can still change based on jurisdiction and overlay conditions. 

Most ADUs require a building permit and plan review. Some sites add extra review layers (coastal, historic, fire access). 

Fee schedules and timing vary by jurisdiction and unit size. Many jurisdictions reduce fees below certain size thresholds, but the categories and triggers differ by city.