1040 sq ft ADU Plan – Permit Ready

A 1040 sq ft single-story two-bedroom ADU with an open-plan layout configured for family rentals and multi-generational living. The layout configures 2 bedrooms and 1.5 baths within a clean, code-aware envelope. Suitable for tenants who want full-house features in an ADU footprint, or homeowners planning ahead for single-level living later in life. The plan includes a covered porch.

Front 3D isometric rendering of a 1040 sq ft 2-bedroom 1-story ADU plan in California — Exterior rendering of the 1040 sq ft permit-ready ADU plan designed as a detached backyard cottage.

Plan A12-1040 Specifications

Base area	1,040 sq ft
Bedrooms	2 Bedrooms
Bathrooms	1.5 Bath
Stories	1-Story
Ridge height	16.5 ft
Roof slope	2:12 & 6:12
Covered porch	161 sq ft

Code & Engineering

This 1040 sq ft single-story ADU plan with 2 bedrooms and 1.5 baths is delivered as a permit-ready architectural plan set developed for California parcels under the state's detached ADU regulations (Government Code §65852.2 and §65852.22).

The architectural plan set comprises the floor plan, exterior elevations, sections capturing the roof-line and interior heights, and dimensioned framing intent. The design follows the California Residential Code (CRC) and is engineered for structural detailing per ASCE 7 and the NDS.

Specific structural details — wall framing, sheathing, shear-wall locations, holdown selection, and connection design — are delivered through the optional Structural Set package and sized to the seismic site class and wind exposure of the specific parcel.

Foundation design is provided as a separate scope to match the right system to each site. Common alternates include slab-on-grade for stable parcels, shallow crawl-space on stem walls for expansive-clay or moisture-prone sites, and pier-and-grade-beam systems for hillside lots, soft soils, or any site where the geotechnical report identifies a need for deeper bearing.

The plan's 16.5 ft ridge height is above the standard 16-foot detached-ADU limit but within California's 18-foot allowance for parcels within ½ mile of a major transit stop or on multifamily-zoned lots. If your parcel qualifies under those provisions, the plan is permit-ready as drawn. If the parcel doesn't qualify, several adaptations are available: plan customization to lower the roof slope or revise the upper-floor elevation so the ridge fits the standard 16-foot limit, configuration as an attached ADU with height matching the primary dwelling, or use as a small single-family residence in a zone permitting that height. Plan customization is offered as an optional design service to match the parcel's specific height envelope.

Available optional services: PE-stamped structural calculations, plan customization for site-specific adaptations (roof slope, elevation, interior layout), custom foundation design sized to the geotechnical report, structural observation visits during framing and finish, and permit support tailored to jurisdiction-specific requirements.