Free 16×24 Open Source Backyard Farmhouse ADU Plans

Free 16×24 Open Source Backyard Farmhouse ADU Plans

Free Open Source Backyard Farmhouse ADU Plans designed by Jay Osborne,, are available in three sizes and dozens of variations.

16×24 Backyard Farmhouse
646 Square Feet

The smallest is 16×24 with 646 square feet. It is designed to work within most local zoning restrictions for ADUs or Accessory Dwelling Units.

A size comparison: The Southern Farmhouse next to the (smallest) Backyard Farmhouse

Working with Zoning Rules

Many areas allow an Accessory Dwelling Unit behind a primary house. Different zoning allows for different sizes.

16×24 Backyard Farmhouse
646 Square Feet

This little 16×24 house, the smallest of the Backyard Farmhouse plans, will fit nearly anywhere. Check your zoning as you plan. If you have checked in the past, check again. Our zoning now allows a much larger ADU than it used to.

16×24 Backyard Farmhouse
646 Square Feet
Notice the Dormer to make the ceiling high enough in the stairwell

Many areas only permit a second house on one lot if it is 800-square-feet or less. But, porches don’t count in the allowed size of an accessory house, at least where we live. Also, if the ceiling is lower than 5-feet, the square footage does not count as living space.  So your 800-square-feet can actually have more usable floor area. This plan has some living area tucked under the roof where the ceiling is lower.

Some walls are short– so you would be expected to put a piece of furniture against those walls.

16×24 Backyard Farmhouse Plan
646 Square Feet

Some residential zoning areas have limits on building height, so the roof of the Backyard Farmhouse stays under 20-feet high.

One of the main purposes of this design is to be short and compact. If the roof ridge is less than 20 feet high, this house can be put in more places. Many local regulations require houses to have a low profile (sometimes ridiculously low).

Along with building height maximums, I designed around ceiling height minimums. Many requirements help keep you from bumping your head against the ceiling. In other cases, it was difficult to maintain the necessary headroom (for instance, the dormer is needed at the staircase).

A size comparison: The Southern Farmhouse next to the (smallest) Backyard Farmhouse

Build the Little House First

You don’t have to have a house to build this house behind. Start by building this little farmhouse, then add the larger house as your family and/or finances grow.

16×24 Backyard Farmhouse
646 Square Feet

Historically in the South, a “little house” was built first, then the larger family home. Later, as children grew up and got married, they lived in the “little house” until they built a home of their own. When I was 10-years-old, our house burned down and a family friend let us live in their “little house” until we got a house dried in enough to live in as we finished it.

This little house is designed to look like a farmhouse in miniature. By keeping the footprint small, it keeps the costs as low as possible.

You could also use this design for a vacation house.

16×24 Backyard Farmhouse with 10×24 Bedroom Suite Rear Addition  and Basement
First Floor Plan
889 square feet

There are options to add on. This shows the Backyard Farmhouse with a Bedroom Suite on the ground floor. A bedroom and bathroom on the first floor is practical if you want to use this as a granny flat.

First Floor Bedroom Suite
16×24 Backyard Farmhouse with Rear Addition and a different stairs configuration
870 Square Feet

This version of the plan has a different configuration to the stairs and living room. With the stairs turned this direction there is a more open floor plan.

Backyard Farmhouse with Basement and Front Porch

Any of the Backyard Farmhouse plans can be built on a slab, a crawlspace and footers, or with a basement garage. A basement garage is especially suitable if you are building on a slope.

Backyard Farmhouse with Basement Garage 24×22

This is a variation of the basement garage plan if the doors can be on the back of the Farmhouse.

16×16 Tiny Farmhouse – 497 Square Feet
Backyard Farmhouses in three sizes; 16×24 with 646 square feet, a little larger 16×28 with 749 square feet, and the largest 16×32 with 857 square feet, all with potential for rear or side additions.

As these plans are completed, they will be available to download free on

*All quotes unless otherwise stated are from the designer Jay Osborne cited from