These terms are often used as if they describe the same thing. They do not. One describes a relationship to an existing property, another often describes compact size or lifestyle, and another describes a design and construction approach. The right choice starts with how the structure will be used and how the property can support it.
ADU / Casita
An accessory dwelling unit is generally a secondary dwelling associated with a primary property. “Casita” is common customer-facing language in some markets, but the applicable legal category is determined by local rules, not by the marketing label.
- Often makes sense when the owner wants independent or flexible living space on a property that already has a primary residence.
- Typical uses can include family, guests, changing household needs or permitted rental use.
- Property-specific zoning, setbacks, access, utilities and other approval requirements need checking before design assumptions become final.
Tiny Home
“Tiny home” is a broad description of a compact residential format. It can refer to different structural and legal configurations, including site-built homes, prefabricated or kit systems, and in some contexts mobile or vehicle-based formats. The term alone does not tell you how a jurisdiction will classify or permit the project.
- Start with it as a compact-design strategy: every square foot has to work harder.
- It can fit a retreat, secondary living, an efficient primary home or a specialized use, depending on the site and approval path.
- Compact size does not eliminate foundations, utilities, weather enclosure, life-safety requirements, mechanical systems or construction coordination.
Small Custom Home
A small custom home is a right-sized primary or secondary residence designed around the owner, property and intended use rather than maximum square footage. It can be modest in size while receiving the same level of site planning, architecture, engineering, systems coordination and finish attention as a much larger house.
- Useful when the project is intended to stand on its own rather than remain accessory to another dwelling.
- Makes sense for owners who prioritize function, land, setting, lower maintenance or a deliberate footprint over building as large as possible.
- Allows the plan, systems and details to respond to the specific site instead of forcing a generic floor plan onto it.
A quick decision framework
ADU / Casita
First question: Can this property support a secondary dwelling? It is generally accessory to an existing primary residence. Local rules determine the actual classification and approval path.
Tiny Home
First question: Do I want a highly compact residential solution? Its relationship to the site varies by system and legal configuration. “Tiny” is not a universal permitting category.
Small Custom Home
First question: Do I want a right-sized stand-alone home designed for this site? A smaller footprint still calls for complete site, system and construction planning.
Understand the use before choosing a label
A homeowner may ask for a “tiny home” when the best project is an ADU, or call something a “casita” when it functions more like a stand-alone small custom home. That is normal. Early feasibility clarifies the intended use, relationship to the property and likely approval path before the team becomes attached to a label.
The construction strategy can then follow the project.
Not sure which category fits?
Describe the property and what you want the space to do. You do not need to know the final label before starting the conversation. Share your goals through the project inquiry below.