True Cost Guide Architects & Engineers Build a Straw Bale or Cob House

How Much Does It Cost to Build a Straw Bale or Cob House?

Typical Range:

$30,000 - $90,000

Cost data is based on research by HomeAdvisor.

Published January 4, 2022

Written by HomeAdvisor.

You can build a small straw bale or a cob cottage for as little as $30,000, while a three-bedroom house can cost around $60,000. The cost can get as high as $90,000 for larger homes, nicer finishes, or additional insulation.

With the ever-growing interest in sustainable home construction, many people consider building homes from straw bale and cob. However, there is a misconception that building a house with natural materials is always more cost-effective than homes built with modern materials.

While it is possible to salvage building materials at a very low cost and build the house yourself, you will still need to put money into the foundation, utilities, windows and doors. And, if you’d like your home to have new and higher-end finishes, the cost will go up from there.

A typical straw bale or cob home built by a contractor will cost the same, if not more, than the cost of a conventional house of the same square footage.

Average Cost to Build a Straw Bale or Cob House

Average Cost	$60,000
High Cost	$90,000
Low Cost	$30,000

Straw Bale and Cob Material Prices

Many people want to build with natural materials because of how inexpensive they can be. You can simply harvest clay, sand and straw from your land and recycle other supplies and materials from construction sites.

A straw bale and cob house material alone can cost anywhere from $3,000 to $6,000 for a small house, including hand-harvested clay and roof rafters.

However, walls are only a small part of the work that goes into a house. Other elements can be pricey, such as the roof, finishes, windows, doors, etc., making the house’s overall price go up.

Building a Straw Bale or Cob House Cost by Square Feet

A straw bale and cob homes cost between $150 and $450 per square foot. The cost can be lower if you can get volunteer labor and use reclaimed materials.

Once you have an idea of what you’d like in your house, the contractor can work with you to put together a true cost estimate.

Find an Architect for Your Cob House Project

Building a Straw Bale or Cob House Cost Factors

Many factors affect the final price of the straw bale or the cob house, such as:

Materials

Materials of the walls count for 10% to 15% of the total cost, depending on where you live.

In some areas, walls’ materials, such as clay and straw, are more salvable than others. In some cases, material may cost more time and money to transport.

Size of the House

Your straw bale or cob house will cost $150 to $450 per square foot. So, when building your straw bale or cob house, opt for small and comfortable. It will not only cost less, but it will also take less time to make and won't require as much maintenance as larger or more conventional homes.

The Finishing Quality

When finishing your home, the type and quality of the materials affect the final cost of your straw bale or cob home. However, your straw bale home will save roughly 75% on heating and cooling costs in the long run.

Labor Cost

Building a straw bale or a cob house is a labor-intensive job. Working with a local contractor will cost 10% to 20% of the total cost of the house but will save you months of intensive work and peace of mind.

Location of the House

Based on the location, there are some differences in material prices and construction costs. The location may also affect the codes, insulation, and roofing of the buildings.

For example, a straw bale home in Oregon may cost about $200 per square foot, while the same house in rural Iowa could cost $100 per square foot, and in California, it might cost $350 per square foot. Consult your local home builder to get a sense of the cost in your area.

DIY vs. Hire a Home Builder

Materials are generally inexpensive, but building a house is labor-intensive. The labor cost makes up 10% to 20% of the total cost of straw bale or a cob home.

The best way to keep the cost lower is to go DIY; the cost to build your own house is often much lower. Do as much of the labor yourself or find a volunteer builder to help you, which isn't that hard to learn if you have basic building skills.

However, it's worth mentioning that it can take nine to 15 months of full-time work for at least two people working every day to complete a project like this.

And while you may save some money, professionals are often faster at construction work than owner-builders, and they’re generally more cost-effective since they can get subcontractors or contractor discounts.

FAQs

What is the difference between a straw bale and cob construction?

Straw bale construction acts as effective insulation that effectively creates thermal comfort throughout the year.

Cob construction absorbs cooling or heat and then releases it slowly while cooling off. Also, cob houses require relatively more time to complete when compared to straw bale homes.

How are straw bale and cob homes different from conventional homes?

Straw bale, cob and conventional homes have foundations, roofs, wall stud frames, kitchens and bathrooms.

The only significant difference is the walls, how they connect to the foundation, support the roof and finish. Straw bale walls consist of straw as the main construction material, while cob walls consist of clay, sand and straw.

How long do straw bale homes last?

If built and maintained correctly, a straw bale home can last 100 years or more.

What are the pros and cons of cob houses?

Pros Of Cob

Economical

The cob is local, making the material easy to assemble and affordable.

Flexible

Cob homes are completely moldable. It’s easy to shape it into curves or any form to have your dream design.

Sustainable

Cod has little or no ecological footprint. The home is entirely recyclable and energy-efficient. Since cob is a porous material, you’ll have completely filtered and pollutant-free air in your home.

Durable

The walls of cob houses are extremely strong, and they can even resist the impact of earthquakes. Cob houses are fire-resistant and can repel unwanted pests.

Cons Of Cob

Takes time to install

Each layer needs to be individually applied and dried before adding the next one, which takes a long time (up to 15 months). The process is very labor-intensive and takes dedication to finish.

Walls are thick

The walls in cob homes are much thicker than in conventional homes, which means you will lose some square footage of your home if not carefully designed.