Choosing an ADU builder is a big decision. But luckily, it doesn’t have to be a difficult one! First check for a valid construction license. If a prospective builder doesn’t have one, walk away. For builders who do have a license, consider the factors below. They’ll help you find an ADU builder you can trust and who has plenty of experience, not just in construction but in accessory dwelling units specifically.
1. Types of ADU construction
Your first question might be, “Should I go with a prefab ADU or a stick-built ADU?” Each home builder tends to specialize in one type or the other. Here are some overall pros and cons of each type of construction.
- Generally lower cost ($199–$420 per square foot)
- No architect or engineering fees
- Controlled building conditions offsite
- Rigorous inspections
- Predictable timeline (no weather delays)
- Generally easier process
- Some customization
- Less noise/disruption
- Generally higher cost ($700–$900 per square foot)
- Must hire architect, general contractor, etc.
- Onsite build with inspections of varying consistency
- Unpredictable timeline (potential weather delays)
- High degree of customization
- More onsite noise/disruption
2. Total cost
Price is paramount for many people. Prefab housing generally costs much less per square foot than stick-built. In fact, site-built homes can be twice as expensive or more per square foot than prefab. Villa’s 10 prefab ADU models start at $199,000 all-inclusive. That means one price covers not just the unit itself but permitting, site prep, delivery, installation, utility hookups, and inspection. Other prefab ADU builders may offer lower-priced units, but everything else you’ll need can add more than $100,000 to the total cost!
3. ADU quality
An initial lower cost doesn’t mean much if you’ll have to shell out for lots of repairs down the road. All manufactured homes must conform to codes established by HUD (the U.S. Department of Urban Housing and Development), which ensure safety, uniformity, durability, and consistency of construction. Villa’s ADUs actually exceed HUD building standards and come with a seven-year warranty on more than 30 items. Site-built homes must conform to codes created by HCD, the California Department of Housing and Community Development.
If you need a backyard home fast, prefab clearly is the way to go. Thanks to well-honed production and process efficiencies, Villa can build and install an ADU as quickly as within six to eight months. Other prefab ADU builders usually take longer, about seven to 10 months, and stick-built construction is the slowest option of all, generally taking at least a year to a year and a half.
5. Project management
Construction project hurdles can be daunting for anyone going it alone. With most prefab ADU builders, you’ll have to research and get permits yourself, hire and manage a general contractor, and coordinate with the utility agencies and any vendors. With stick-built housing, you’ll need to do all that plus hire an architect and possibly an engineer. But Villa’s experts will take care of everything for you, from permitting to keys in hand.
6. Customer service
Some housing sellers seem to just want to turn a buck. Others may offer some help or advice after you buy, but it’s not guaranteed. And anyone who’s ever had work done around the home knows that general contractors vary widely in terms of capability and attitude.
Also ask friends and family for referrals, read reviews, and check out recommendations in online groups. Villa is known for its excellent customer service and happy customers.
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