ABOUT:
Straw bale has evolved into a new era with prefabricated panels. 

LOCAL PROJECT:
(coming)

PROS/CONS:

Pros:
Environmentally friendly
Some undetermined more manufacturing than straw bales, much less embodied carbon than traditional walls.
Natural materials - No/low VOCs

Cons:
Cost
Only available in limited locations - may require distant shipping
Can be difficult to put together (based on local project feedback)
Generally not DIY, requires a general contractor/equipment

RESOURCES:
https://www.newframeworks.com/

Straw bale may not be the norm in Cook County, but it is not a stranger. While people generally associate straw bale or earthen construction with the dry climate of the Southwest, straw bale is well suited to cold, snowy climates, as well. The key is the vapor management of the natural wall materials.

Our visit to this home in early February was incredibly comfortable.
This approximately 800 sqare foot one-story home was built by a couple with some supportive advice from a friend and an occasional helper in 2008-2009. It remains a cozy, well-functioning home that has stood the test of the years.

The home has approximately a 24x36 footprint.
It took two people just over 2 years to complete doing the work themselves. In the first year, they focused on the earthwork and did most of the building the second year, with some finishing work after that. 

Foundation:
The foundation is about 6 ft deep. It has a perimeter rubble trench which provides drainage. Over that, are insulated concrete forms (ICFs) set on the rubble trench that come up about a foot above grade. 
They said if would have done anything different, they might have added a bond beam around the perimeter over the rubble trench for the form to more easily set upon before concrete was poured in.

Inside the perimeter is a deep sand bed. This provides the passive heat battery that helps keep temperatures steady through the winter. Within that, are inlaid pvc piping connected to a hydronic/thermal solar panels (closed loop system) that brings heat to the sand and ‘charges' it with heat.. This system is typically turned on late summer to heat the sand below throughout the cold season, and turned off again in late winter so the home doesn’t overheat as the weather warms.

Planning must be carefully done before laying the foundation layers, so the pipes can be laid in the proper places before the groundwork is done. This includes things like the thermal system (above) as well as any drainage pipes. At the time of this build, it was appropriate to have drainage of grey water as long as water was being hand-carried in and was non-pressurized. (Building codes should always be referred to before building). The final floor is a slab on grade, and tile was chosen to finish most of the interior living area.

Roof -
Metal roof over purchased trusses with blown in 2 ft of cellulose over plywood for the ceiling, leaving a ‘cold’ roof that has performed really well.

Frame - 
There are many options for framing a straw bale, as well as using the straw bale walls as the support structure. For this project, the frame was post and beam with straw infill. Alone, this frame couldn't have stood as a structure on its own, but the straw bales and plaster coatings create a solid, sturdy structure.

Walls -
The straw bales were sourced at the time from Thunder Bay. 
The base coat of plaster utilized clay from the site, (approximately 6?str tons of it?)
The site clay required a fair amount of processing. It had to be screeted through wire mesh in order to get the rocks and larger elements out. That was one of the more difficult tasks.
​
 - first coat was heavier straw and clay from site
 - second coat was chopped straw and clay soil from site
 - final exterior coat was lime plaster (and purchased sand?)
 - Windows were obtained from Builder Materials Outlet (BMO) installed flush to the exterior. A discussion we had was that there is some school of thought that windows installed in the middle of the wall might be more resistant to condensation. They like having the window to the exterior

Interior - 
- First coat was heavier straw and clay from the site
 - Second coat was chopped straw and clay soil from the site
 - Final exterior coat was specially purchased 70% light colored sand to 30% clay from Continental Clay, and they used mineral pigments to create an aquamarine and purplish blue wall colors.
 - The finish is smooth and satiny

Other 
Something to think about is planning where you want to hang heavy things on the wall like cabinets, and inlaying beams into the walls to support those structures.
They had air ventilation going into the home behind the firebox, as well as a small pvc pipe air outflow vent near the ceiling.
- There is a small wood cookstove for heat and cooking. They use about a cord of wood per year.
- Water is carried in, and they have an outhouse
- Connected to grid power - Electricity use is about $20/month
- They have a 'bucket shower' system that is lined with a water-resistant lime putty and marble dust over cement board and burnished just as it is drying to a fine finish.

 Performance - 
They can leave their house for weeks in the winter and it won’t freeze. The lowest the sand has gotten is 58 degrees in the coldest times over the years.
There has not been any cracking in the interior.
There has been some cracking on the exterior, especially at the corners of windows, which is easily repaired with mineral paint.
The small wood stove is enough to provide comfortable heat in the winter.

Using minimal cement for a solid and affordable foundation

One couple has been building a home themselves from the ground up. They turned ledge rock, which is often a challenge, into an opportunity. 
Rather than trying to blast or having to select a different site, they took advantage of the strength of the rock to significantly reduce their cement use for the foundation.

A diverse group met at Cook County Higher Education on Tuesday, October 14th to kick off the Northwoods Sustainable and Resilient Housing project, and to share examples of sustainable housing in the community, as well as what people wanted from this group moving forward.

Over 20 attendees represented backgrounds in environmental education, building, DIY construction, public policy, real estate, and residents who installed or are living in homes with sustainable features. We heard about local projects with pre-fab straw bale panels, timber framing, geothermal heat, solar water heat, passive house technologies, natural building materials, solar, masonry heaters, micro-off grid electric systems, thermal mass temperature regulation, housing cooperatives, earthen floors, log building, and more. Challenges and also opportunities were identified.

Affordable housing was an integral part of the conversation. Jeff Brand of the Housing Redevelopment Authority (HRA) restated some of the findings from the prior survey that was done. This included that Cook County needed 610 overall dwellings. Of those, 150 units of housing at less than 50% of the area median household income for those making under $45,000. Building the traditional and historic ways, they cannot be built fast enough or affordably enough without significant subsidies.

If you would like to hear the full conversation, click the link here:

Northwoods Sustainable Housing Project - Community Roundtable Video Recording
https://mycche.org/aiovg_videos/northwoods-sustainable-housing-project-community-roundtable/
.

We visited an off-grid timber frame home build north of Hoveland and were introduced to hemp batt insulation. This insulation is easy to work with. It is flexible yet sturdy like rock wool, but takes much less energy to produce. It naturally balances moisture, is very insulating, non-toxic, and even smells sweet. 
The batts had to be ordered from a distant location, but even with shipping, the total cost was less than that of other alternatives.

Some of the benefits of Hemp insulation are:
Thermal Performance: The R-value is about R-3.7, better than fiberglass.
Acoustics: The dense material has excellent noise-dampening qualities
Moisture: Regulates moisture without mold and mildew growth.
Healthy: Made from plant fibers. No harmful chemicals, VOCs, or irritants. Safe: Requires no special safety equipment 
Pest Resistance: Silica and low protein make it naturally resistant 
Durability: Resistant to settling over time, and can last many decades 

Find more information about hemp is on the Resources page.

In Cook County, one resource we have in abundant supply is wood. Cordwood structures can be made from timber harvested from sustainable forest management practices, which could include thinning stands, or using trees that have to be taken down in yards or properties, and from stands of spruce and fir felled to manage spruce budworm. Normally, the logs are dried, round logs, but in the case of the sauna structure, square timber scraps were used from North House Folk School timber framing projects.

​Cordwood buildings are thick-walled, structures in which short, thick logs are piled width-wise using mortar or cob to bind them in place. This forms a highly insulating and energy-efficient wall with significant thermal mass. The walls can additionally be insulated by a central layer of sawdust or other material to prevent leakage from cracks and address thermal bridging. 

Read more about cordwood building on the Resources page.

As we were just beginning this project, a local couple had just sent out an invitation to friends and community to build their earthen floor. The project was inspired by the book 'Earthen Floors' by Sukita Reay Crimmel, James Thomson. ​Without specific experience doing this kind of floor, they brought in the expertise of friends from Alaska to guide the process. 

Earthen floors use non-toxic, natural materials, and create thermal mass to hold both cooling in the summer and heat in the winter. They are made with a local material we have in abundance - clay, along with sand, water and straw. The project definitely checks the sustainable, healthy, and resilient, boxes, and possibly the affordable box with volunteer help.

The project was the upstairs floor for a living and kitchen area, so different from others that form a foundational floor. It was scheduled to start on a Wednesday and finish on a Sunday. It was completed with the help of a dozen family and friends. And after a lot of preparation to set up processing stations for each material.

Discussion points, random thoughts and questions:
​Challenges: labor intensive, time intensive, requires room for staging, access to materials
Questions: Is it possible for builders? What is the cost after factoring in labor? How could it make sense compared to a traditional cement slab foundation and floor?