900 Sq Ft Floor Plans You Can Actually Build in California

These are the 900 sq ft floor plans we take through permitting in California, and you can walk one in 3D.

  • 1,200 sq ftState max for a new detached ADU
  • 1,000 sq ftLocal cap floor, 2 bedrooms
  • 30 × 30 ftA real 900 sq ft footprint

selected from our curated collection

Our 900 Sq Ft Floor Plans

Four layouts, all drawn for California lots. Depth, not a catalog of hundreds.

900 sq ft 2 bed 2 bath ADU floor plan

900 sq ft, 2 bed / 2 bath

The full 900 square feet. The second bath makes it rentable as a true co-living space. Fort two students. or for two colleagues.

ADU floor plan 2 bd 1 bath

858 sq ft, 2 bed / 1 bath

One bigger bathroom buys a larger great room, easy to customize for any backyard L shape. Note the separate laundry space.

900 sq ft ADU floor plan

808 sq ft, 2 bed / 1 bath

Still two bedrooms. One bedroom with a real walk in closet and en suite bathroom, a true primary bedroom.

L-shaped ADU plan 892 sq ft

982 sq ft, 2 bed/1bath

L-shape option, with an easy indoor-outdoor flow.

DIMENSIONS

How Big Is 900 Square Feet?

The number gives the area. Dimensions tell you whether it fits.

FOOTPRINT

30 × 30 ft

A real plan at exactly those dimensions: two bedrooms, one bath, single story. What the bedrooms and bath leave is your living space.

ALSO FITS

25 × 36 ft

Same area, five feet narrower and six deeper: the shape for a generous rear yard.

TYPICAL

2 bed / 12 bath

What this size is usually sold as: single story, two bedrooms, one or two baths.

2 bedroom ADU floor plans

BEDROOM COUNT

900 Square Feet House Plans: 2 Bedroom

Two bedrooms at 900 sq ft sit under the 1,000 sq ft floor a California city cannot cap below.

  • 2 bed / 1 bath

    The most shared living space of the three. One bathroom is the trade off.

  • 2 bed / 2 bath

    Rentable, or workable for two generations. The second bath can become one en suite.

  • 1 bed plus an office

    When the second room need not be a legal bedroom, your city may limit at 850 sq ft.

963 sq ft 2b1b ADU floor plan

IN 3D and Augmented Reality

900 Square Feet House Plans in 3D

A floor plan is a drawing seen from above in 2D. We can show all our plans as an online walkthrough before permitting starts. One bedroom or two? That choice sets your size cap; the 2 bedroom ADU floor plans go deeper. Either side of 900: the 800 sq ft house plan and the 1,000 sq ft house plans.

DESIGN

900 Square Feet House Design

900 sq ft 2 bed 2 bath ADU floor plan

No unused spaces. A corridor here is floor area you only walk through. The plan that works puts kitchen, dining and living in one volume.

PERMIT process

From a 900 Sq Ft Plan to a Permit

A PDF of a stock plan has 10% of what a California building plan requires.

  1. Confirm what your lot allows

    Your city cannot hold a detached ADU below 16 feet, or 18 within one-half mile walking distance of a major transit stop or high-quality transit corridor, and may allow more. A conversion has no size limit. One of many items we check at the feasibility phase.

  2. Fill the gaps a stock plan leaves

    Bought plans exclude the site plans, mechanical and plumbing drawings and Title 24 energy calculations. In earthquake-prone California you will need a state-licensed structural engineer provide drawings and calculations. Some cities are also requiring a geotechnical report, and you need it before the structural engineer designs the foundation.

  3. Submit to your building department

    Plans go in with the site plan and energy calculations. An unrelated code violation cannot block them unless it threatens health and safety or the ADU work touches it.

  4. Build

    We hand the permitted set to your builder.

FAQ

Frequently Asked Questions

Thirty by thirty feet, or 20 × 45 if the backyard is narrow. Think whole small house, not a room addition: two bedrooms, a bath and one shared living volume, with living space taking what the bedrooms leave.

Modular 2 bedroom 1 bathroom ADU unit installed

Start With a Plan That Fits Your Lot

NEXT STEP

Fill in the address and see what 900 square feet does on your lot: setbacks, height, bedroom count. Cost comes out of site work, foundation, utility runs and finish level, so we price it once we have seen the parcel. Our ADU house plans start there, not at checkout.