Boxabl One Bedroom Casita: Foundation Plans & Requirements
The multi-module one-bedroom configuration — a full 1 bed / 1 bath home at 722 sq ft.
Key Specs for Foundation Design
Square Footage
722 sq ft
Footprint
19' x 38'
Configuration
1 Bed / 1 Bath
Weight
Multi-module configuration — foundation must align both modules and their connection points
What the 1-Bed Casita Foundation Must Do
Two connected modules create a 19' x 38' footprint — the foundation must be laid out precisely so both modules and the module-to-module connection line up.
The inter-module joint is a structural connection: differential settlement between module bearing lines is the failure mode the foundation design prevents.
Slab-on-grade with continuous perimeter bearing is the most common solution; crawlspace stem walls work well where frost depth requires deeper footings.
Anchorage requirements follow the same ESR-4725 SIP values as the other Casita models, applied across the longer perimeter.
Approval status: Follows the same state pathways as the Casita line; check your state page for the approval route where you live.
Foundation Options & Typical Costs
National planning ranges — your state's frost depth, wind, seismic, and soils pick the winner. Find your state on our state-by-state guides.
Concrete Slab
from $6,000A single layer of concrete, several inches thick. Simple and cost-effective.
Best for: Flat terrain, warm climates, budget-conscious projects
Crawlspace
from $12,000Elevates the home 18-36 inches, providing access to plumbing and electrical systems.
Best for: Sloped lots, areas with moisture concerns, easy maintenance access
Pier & Beam
from $5,000Concrete piers supporting beams and joists. Ideal for challenging terrain.
Best for: Sloped lots, rocky soil, environmentally sensitive areas
Full Basement
from $25,000A full-height underground level, offering additional living or storage space.
Best for: Cold climates, need for extra space, areas with deep frost lines
1-Bed Casita FAQs
Does the 1-Bed Casita need a bigger foundation than the Studio?
Yes — double the footprint (19' x 38' vs 19' x 19') and a structural module-to-module connection that requires precise foundation layout and flatness tolerances. It's the same engineering discipline, over a larger plan.
Can the two modules settle differently?
That's exactly what the foundation is engineered to prevent. Continuous footings sized for your soil, or piers with adequate bearing, keep both modules on the same plane so the connection stays tight.
What does foundation engineering cost for the 1-Bed?
The same package pricing applies — PE-stamped plans from $749. Construction costs scale with the larger footprint: roughly $8,000–$18,000 for slab depending on region.
We provide foundation engineering only — Boxabl units are sold separately by Boxabl Inc. Specs above reflect Boxabl's published documentation and may change; always confirm current specs with the manufacturer.