Outbuilding Cost Guides

Outbuildings cost $2,200 to $22,000, averaging $10,000 for a structure measuring 12 by 12 feet. You’ll pay $15 to $150 per square foot, depending mostly on materials and prefab or custom. Prefab metal kits are the least expensive at $10 to $30 per square foot. If you want custom brick construction, plan to spend $50 to $150 per square foot. Finished workshops run $30 to $200 per square foot.

Find out how much your project will cost.

Select your Outbuilding project

building site being prepared for construction
Clear Land
(2,184 projects)
$3,747 Average National Cost
newly built barn on farm with tractor
Build a Barn, Shed or Playhouse
(683 projects)
$3,395 Average National Cost
welder creating a custom metal structure in workshop
Create a Custom Metal Structure or Object
(639 projects)
$2,065 Average National Cost
farmer repairing the siding on barn with hammer
Repair a Shed, Barn, or Playhouse
(476 projects)
$1,147 Average National Cost
wooden playset with slide installed in backyard of house
Install a Playground or Swing Set
(339 projects)
$501 Average National Cost
built-in outdoor kitchen with grill and sink
Build an Outdoor Kitchen
(272 projects)
$16,251 Average National Cost
wooden gazebo built in large backyard with landscaping
Repair a Gazebo
(203 projects)
$1,268 Average National Cost
wooden gazebo recently built in backyard garden
Build a Gazebo
(186 projects)
$5,285 Average National Cost
construction permit application being filled out
Get a Building Permit
(164 projects)
$1,658 Average National Cost
carport at the end of driveway next to house
Build a Carport
(154 projects)
$8,796 Average National Cost
Red storm shelter door in front of a brick house
Build a Storm Shelter
(117 projects)
$7,575 Average National Cost
neon sign installed on storefront
Make and Install Signs
(33 projects)
$464 Average National Cost
handyman on a ladder repairing the roof of a greenhouse
Repair a Greenhouse
(14 projects)
$1,460 Average National Cost
greenhouse full of plants built in backyard garden
Build a Greenhouse
(13 projects)
$8,689 Average National Cost

Outbuildings can be a great way to increase living space on your property without having to add onto your house. If you’re trying to stick to a budget, selecting one of the many prefab options may help you save money. You can also make the structure as comfortable as your home, although it costs more. Consider these projects to learn more about what you can expect to pay.

Outbuilding Cost Estimator*


* Assumes a structure measuring 12’ x 12’

Average Cost of Building an Outbuilding

The cost to build an outbuilding ranges from $1,000 to $60,000, averaging $10,000 for most common sizes. Estimates depend on the size and the type of material.

8’ x 8’$1,000 - $9,600
10’ x 10’$1,500 - $15,000
12’ x 12’$2,200 - $22,000
10’ x 20’$3,000 - $30,000
20’ x 20’$6,000 - $60,000

Outbuilding Costs Per Square Foot

Outbuildings cost $15 to $150 per square foot. You’re likely to spend the most on expensive materials like brick or additional finishing, such as HVAC or plumbing.

Steel/Metal$15 - $70
Wood$20 - $100
Concrete$15 - $50
Stone or Brick$50 - $150

Steel or Metal Outbuilding Prices

Steel or metal outbuilding prices range from $15 to $70 per square foot. You’ll pay less to have a pro assemble a prefab kit, and more for them to build it from scratch. This style tends to be the most affordable unless you’re planning to line it with Kevlar to make it impact-resistant.

Concrete, Stone or Brick Outbuildings

If you want a concrete outbuilding, you can expect to pay $15 to $50 per square foot. The material is the least expensive option, but it’s heavy. More labor leads to a higher price.

Stone or brick outbuildings cost $50 to $150 per square foot. These materials are the most expensive, at around $30 to $100 per square foot. You’ll probably need custom construction, which explains the higher price.

Building Permits

A building permit costs $500 to $2,300. Prices depend on your area and the size of the project.

Building a second structure onto your existing property usually requires building permits. Every city has specific rules you must follow, such as the outbuilding’s proximity to your house. Pros may or may not handle this for you, so it’s wise to ask. If you live in a community with a homeowners association, you’ll probably also need to get permission from them.

Cost to Build a Workshop in the Backyard

The price to build a workshop in the backyard ranges from $6,000 to $120,000, or $30 to $200 per square foot. The total depends on size, materials and finish.

10’ x 20’$6,000 - $40,000
20’ x 20’$12,000 - $80,000
20’ x 30’$18,000 - $120,000

Cost to Build a Shop Per Square Foot

Building a shop costs $30 to $200 per square foot. You’ll pay $30 to $50 per square foot for a metal prefab kit with minimal finishing. Custom options run $50 to $200 per square foot.

Finish Cost for a Shop

Finishing may add $10 to $100 per square foot to the total. If you want a completely finished wood shop or auto shop, you can expect to pay the cost to build a house, which is $100 to $200 per square foot. On top of construction or assembly, the project may require these services:

Keep in mind that the more your outbuilding resembles the level of finishing in your house, the more expensive it is. If you’re trying to save money, a simple storage shed that you occasionally use for projects may only need battery-operated lighting and a cement floor.

Other Outbuilding Types

Outbuilding prices range from $400 to $180,000. You’ll pay the least for an inexpensive treehouse or playhouse, and the most for a pool house.

Barn$10,000 - $100,000
Shed$200 - $30,000
Outhouse$1,500 - $5,000
Garden Room$10,000 - $70,000
Greenhouse$7,400 - $28,400
Conservatory$10,000 - $80,000
Bomb Shelter$37,000 - $65,500
Storm Shelter$2,600 - $10,000
Treehouse$400 - $15,000
Playhouse$500 - $15,000
Pool House$27,000 - $180,000
Guest House$45,000 - $100,000

Build a Barn or Shed

Building a barn costs $10,000 to $100,000. The price to build a shed ranges from $200 to $30,000.

Cost to Build an Outhouse

The cost to build an outhouse is $1,500 to $5,000. Options with a composting toilet system run the most.

Cost to Build a Garden Room or Office

Garden room prices range from $10,000 to $70,000, depending on the type. Modern styles run on the higher end.

Greenhouses or Conservatories

The price to build a greenhouse is $7,400 to $28,400, or about $25 per square foot. Average sizes range from 500 to 1,000 square feet. A conservatory costs $10,000 to $80,000.

Bomb or Storm Shelters

Building a storm shelter costs $2,600 to $10,000. By comparison, the price to build a bomb shelter is $37,000 to $65,500.

Treehouse or Playhouse

The cost to build a playhouse is $500 to $15,000. Prefab kits are $500 to $5,000. Building a treehouse costs $400 to $15,000. Custom or large designs run higher.

Pool or Guest House

The price to build a pool house ranges from $27,000 to $180,000. Building a guest house costs $45,000 to $100,000.

Prefab Outbuilding Prices. vs Custom Structures

Prefab outbuilding prices usually run $10 to $30 per square foot, not including labor. For most custom structures, you’ll pay at least $50 per square foot.

A good rule of thumb is that more customization leads to higher prices. A pre-fabricated building kit varies based on:

  • Size

  • Complexity

  • Quality of materials

  • Brand name

Kits that cost less may not have as many options. If you want a solid wood or brick outbuilding, you’ll need to find a custom builder.


How much does it cost to build a small workshop?

The cost to build a small workshop measuring 100 square feet is $3,000 to $20,000, or $30 to $200 per square foot.

Who can create workshop plans?

The cost to hire an architect to create workshop plans is $2,500 to $8,000. For a fully-finished structure, you’ll probably need one to ensure the building is sound.

Do outbuildings increase property value?

Outbuildings may increase property value, but it depends on a few factors. A finished workshop or guest house might add up to $20,000. By comparison, sheds with no foundation usually don’t count on an appraisal.

Can I DIY build an outbuilding?

You can build your own outbuilding using a prefab kit that costs $10 to $30 per square foot. Keep in mind that you’ll need at least two people who can carry up to 75 pounds. Hiring a pro usually takes less time.

How can I build a wood shop or workshop on a budget?

If you’re planning to build a woodshop or workshop on a budget, try these cost-saving methods:

  • Buy a prefab kit made of steel.

  • Hire a pro to pour a concrete pad, but assemble the kit yourself.

  • Consider battery-operated tools and lighting instead of running wiring.