Additions and Conversions · ADUs and Conversions
ADU Installation Cost, Permits and Who Does the Work
First-time installation of adu on a single-family home, typically handled by a general contractor.
Model reviewed August 2026
Typical cost
$180,000
National, standard scope
Range
$90,000 – $350,000
Low to high scope
Trade
General contractor
DIY difficulty 1/5
Permit
Usually required
Plan on a permit and inspection
Do I need a permit for adu installation?
Usually yes
ADU work at this scope touches structure, life safety or a permitted trade in most jurisdictions, so a permit and inspection are normally required. Always confirm with the building department that has jurisdiction over your address.
Cost breakdown
Modeled national figures for a standard single-family job.
| Low endSimple scope, easy access, no surprises | $90,000 |
|---|---|
| TypicalWhat most homeowners pay | $180,000 |
| High endLarge scope, upgrades or difficult conditions | $350,000 |
| Job type | Project |
| Cost varies by location | High |
Variants
Distinct options within this job that buyers compare before committing.
Calculators for this job
Related jobs
Related projects homeowners often plan together.
Also searched as
You may also hear this called:
install adu · new adu · adu install cost · put in adu
Frequently asked questions
How much does adu installation cost?
Most homeowners pay between $90,000 and $350,000, with $180,000 typical for a standard single-family job. Figures are modeled national estimates, not quotes.
Do I need a permit for adu work?
Yes — in most jurisdictions this job is permitted and inspected. Check your local building department before work starts.
Who does adu installation?
A general contractor handles this job. DIY difficulty is rated 1/5 (5 = very DIY friendly).
Does the price change much by location?
Yes. Across the states we price, the typical cost ranges from $162,000 to $235,800 — about a 46% spread — driven by labor rates, code requirements and permit fees.