WHAT TO KNOW FIRST
An attached ADU creates an independent dwelling connected to the primary home. The scope must coordinate the new unit with shared walls, rooflines, foundations, utilities, fire and life-safety work, privacy, and the occupied residence.
- Confirm that an attached unit serves the household better than a detached ADU.
- Investigate the existing home before defining structural and utility work.
- Keep the attached ADU and JADU categories distinct.
Add independent living space close to the main home.
An attached ADU may suit a property where the household wants a separate dwelling but prefers to connect new construction to the residence. Evaluate outdoor-space impact, entries, privacy, parking context, existing rooms, and how construction affects daily life. Compare the option with a detached backyard ADU before fixing the project type.
The existing building becomes part of the job.
Document the foundation, exterior wall, roof, openings, utilities, drainage, equipment, prior additions, and available records in the connection area. Qualified professionals must determine which investigations and design work apply; a surface observation does not establish the structural scope.
Ask how the proposed connection handles weather, structure, fire and sound separation, roof drainage, floor transitions, heating and cooling, hot water, electrical loads, plumbing access, and future maintenance. If the main home stays occupied, the scope should also state temporary protection, security, service interruptions, and restoration on the household side of the work.
An attached ADU is different from a JADU created within the residence. Use the property-requirements checklist to keep category and ownership questions visible.
Define work on both sides of the connection.
The proposal should explain new construction, alterations to the main house, weather protection, utility work, temporary protection, interior restoration, permit coordination, inspections, finish allowances, and exclusions. Review the construction stages and complete cost scope.
Make the drawing basis explicit. If the proposal uses an early concept, state which engineering, energy, utility, finish, and City-comment changes remain unpriced. Identify whether patios, irrigation, planting, fencing, paving, exterior lighting, and disturbed interior finishes are restored, replaced, or excluded.
Call about your Irvine property.
Call (949) 763-5237 with the property address, preferred unit arrangement, and available drawings or photographs.
Tell us about the home and the proposed addition.
Use the estimate preparation page before calling. Return to Irvine ADU Contractor for all four site-built ADU services.
PRIMARY SOURCES
Public records connected to the project
Links checked September 7, 2026.
Recheck these links before a drawing or estimate relies on the summary.
KEEP READING
Check the issue that affects the next decision.
TALK WITH THE BUILDER
Call when you are ready to discuss the site.
Tell us which part of the property you are considering. A few current photos make the first discussion more specific.