Prefab vs. Stick Build ADUs

Prefabricated homes are gaining popularity in the United States for a multitude of reasons. The process of building a home off-site and having it installed on your property provides a much more controlled, timely, and often less expensive alternative to a stick build project. Furthermore, new prefab ADU options are appearing which are more customizable, high-quality, and accessible than ever before.

Below, I’ve outlined the pros and cons of choosing a pre-fab ADU vs. a traditional stick build for easy comparison:

Pre-fabricated ADU

Fixed Costs

High Level of Flexibility 

No Architect or Engineering Fees

Offsite Build

$199–420 / sq ft

2-4 Week Onsite Install 

No Weather Delays

Fixed Timeline

Stick Build ADU

Variable Costs 

Complete Flexibility

Varied Architect and Engineering Fees

Onsite Build

$700–900 / sq ft

6-12 Months of Onsite Construction

Weather Delays 

Variable Timeline

Why is building a prefab ADU more convenient?

Building off-site comes with major advantages. Having your home feel like a construction zone can be unpleasant, and most would prefer to minimize the amount of time spent with strangers doing disruptive work in their yard. When your ADU is delivered to your property entirely constructed, there is minimal intrusive, loud on-site work to be done.

Unpredictable factors such as weather delays can extend the build phase of a stick-build ADU project. Prefab options are able to control for this, as your ADU is constructed indoors. This allows for you to accurately forecast how long your project will take and makes the process as short and painless as possible.

Why are prefab options so much more cost-effective?

Normally, applying for permits, managing contractors and subcontractors, and finding interior and exterior finishes are all slow, complicated processes that allow for different parties to up-charge at every step of the way. Opting for a prefabricated home over a stick build allows you to dodge excess costs such as architecture and engineering fees. It also cuts down the time investment for you.

For example, San Francisco-based prefab ADU company Habitat offers all inclusive pricing for its 11 different models. They wrap everything – site evaluation, permit package creation and submission, construction, site work (foundation, trenching, utility connections, etc.), interior and exterior finishes, fixtures, and appliances – into one fixed cost. Not only does this give you full transparency around cost and timeline, but it minimizes them both.

Want to see if your property is eligible for a pre-fab ADU? Habitat‘s two-minute assessment is a great place to start.
Take this two-minute assessment to get started.