ADU builder in Lehi, Utah
Cocoon Homes is a Lehi, Utah ADU builder that designs, permits and builds backyard ADUs in Lehi — typically $85,000–$200,000 all-in.
Detached ADUs are allowed in Lehi: the City Council adopted its SB284 update on July 14, 2026, lowering the lot minimum to 11,000 sq ft and dropping the old 1,300 sq ft size cap.
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Lehi ADU rules at a glance
| Rule | Lehi |
|---|---|
| Detached ADU | Allowed — Council adopted the SB284 update July 14, 2026 |
| Lot minimum | 11,000 sq ft (was 14,520) |
| Size | Must be smaller than the primary home (1,300 sq ft cap dropped) |
| Setback | 6 ft from the existing home |
| Owner-occupancy | Required — primary or the detached unit |
| Parking | 2 off-street spaces if the ADU is over 650 sq ft |
Last reviewed October 6, 2026 · Official source: Lehi City · Lehi on our Utah ADU rules tracker
Which Cocoon floor plans fit Lehi's rules
| Plan | Size | Fits Lehi's size rules? | Added parking |
|---|---|---|---|
| 100 Series studio (home ~$63K) | 170 sq ft | Yes, if your house is larger than 170 sq ft | None required under 650 sq ft; 1 space recommended |
| 200 Series (home ~$73K) | 240 sq ft | Yes, if your house is larger than 240 sq ft | None required under 650 sq ft; 1 space recommended |
| 300 Series one-bedroom, most popular (home ~$84K) | 300 sq ft | Yes, if your house is larger than 300 sq ft | None required under 650 sq ft; 1 space recommended |
| 400 Series (home ~$94K) | 400 sq ft | Yes, if your house is larger than 400 sq ft | None required under 650 sq ft; 1 space recommended |
| 500 Series two-bedroom (home ~$109K) | 500 sq ft | Yes, if your house is larger than 500 sq ft | None required under 650 sq ft; 1 space recommended |
Most owners go wider or add square footage; custom footprints up to Lehi's limit (smaller than your primary home) are available, and we size them to the rules before design. Going past 650 sq ft brings in Lehi's 2-space parking requirement, so we plan the driveway at the same time.
What an ADU costs in Lehi
A Cocoon ADU in Lehi typically runs $85,000–$200,000 all-in, home plus site work. Our most popular plan, the 300 Series one-bedroom, comes in around $113,000–$126,000 all-in. Site work, utilities and city costs add 35–50% on top of the home price, depending on how far your sewer, water and power have to run. For comparison, a traditional custom-built ADU runs $200,000–$400,000 or more. Full breakdown: what an ADU actually costs in Utah.
What an ADU rents for in Lehi
A typical one-bedroom in Lehi rents for about $1,379 a month (Rent.com, 2026). At that rate, a 300 Series ADU at $113,000–$126,000 all-in pays back in roughly 6.8–7.6 years of gross rent, before taxes, insurance and upkeep. More on the math: how much rent a backyard ADU earns in Utah.
How we build your ADU in Lehi
- Lot check. We read your lot against Lehi's adopted ordinance: the 11,000 sq ft minimum, the 6 ft separation from your home, and parking.
- Plan and finishes. Pick a floor plan or a custom footprint, then your finishes.
- Engineer-stamped plans submitted to Lehi. We prepare the permit set and submit it to the city.
- On-site build. Our Utah crew builds your ADU on a permanent foundation on your lot.
- Final inspection, utilities, keys. We close out inspections and utility connections and hand you the keys.
Lehi ADU questions
Can I build an ADU in Lehi?
Who builds ADUs in Lehi?
Do I have to live on the property?
How much parking does an ADU need in Lehi?
Is there a maximum ADU size in Lehi?
Building in Lehi? We'll check your lot first.
Tell us your address and we'll tell you what Lehi's rules allow on your lot before you spend anything on design. Free, and you'll hear from us the same business day.
Ready to talk? Book a 30-minute call.
More on Utah ADUs: Utah ADU homes · ADU rules in 34 Utah cities · ADU vs. tiny home