California was the first state in the US to adopt a statewide, mandatory building code. The California Green Building Standards Codes, or CalGreen, took effect in January 2011. It applies only to new construction of low-rise residential, public and commercial buildings, including offices, retail, schools and medical services buildings. Sadly, retrofits, additions, remodels and repairs are not included in the code.

There are two voluntary tiers, I and II, above and beyond the code intended to increase efficiency, Tier II being the most efficient. However, implementation, documentation and verification rules are vague and confusing, and they may conflict with third party rating systems. There also need to be special inspections and new fees. Despite the guidebook for the tiers, experts need to be trained.

Goals of CalGreen

The goals of CalGreen are in line with California’s new global warming law. It will help meet their emission targets of a 25% reduction of greenhouse gas emissions by 2020. There are mandatory emissions caps for certain buildings starting in 2012.

CalGreen focuses on:

• reducing construction waste by 50% through recycling
• cutting water use 20% with efficient plumbing fixtures and landscaping irrigation
• improving indoor air quality with low VOC products
• reducing environmental impact during and after construction with proper site selection and clean up
• suitable materials
• conserving natural resources

Compliance must be documented, and there are performance requirements for certain buildings.

CalGreen does not replace local codes and ordinances, but it can be amended for local conditions and to make the code more stringent. LEED can be used for certification as long as it does not interfere with CalGreen. Aside from conserving resources, CalGreen is also creating jobs. I just wish it applied to renovations!

Energy Efficient Specialty Codse (OEESC) in Oregon

The statewide Oregon Energy Efficiency Specialty Code (OEESC) encompasses more than building, and it will improve upon their current codes, policy and programs. This is an energy code focusing on energy efficiency, renewable energy, water conservation and charging stations for electric vehicles. That’s my favorite part – looking to the future by addressing electric vehicle needs!

Before Oregon enacted a stringent energy code, it was third in the US for building code energy efficiency and fourth for overall energy efficiency policy and programs. Oregon has always been ahead of other states in many ways, so this does not surprise me.

These new standards will reduce energy use in commercial buildings by 15%. Increased insulation, automatic lighting controls and more efficient HVAC systems are required. The Oregon Reach Code is optional for those wishing to design and build beyond the energy code.

Oregon’s statewide code for solar installation is the first in the country, and water catchment and recycling has new standards, too.

The 2012 national model code will probably have some of the OEESC incorporated into it. That’s how stringent and effective it is!

Green building codes in Washington state

Washington is home to Richland, the first local government to adopt the International Green Construction Code (IGCC). Even though this is not a mandatory code, the city thought it was a great way to help educate designers, architects and property owners about energy efficiency and conservation.

In July 2010, the Washington State Energy Code became law. It is aligned with the state’s 30-year plan to reduce waste and toxicity, and increase recycling. As of 2005, in order to receive public funding, new construction and renovations must be built to LEED Silver standards. On the other hand, HVAC products must adhere to the federal standards code, which is less stringent. This created a lawsuit, which happened in Albuquerque, NM, too.

There are three state mandated certification programs:

• Evergreen Sustainable Development Standard for Affordable Housing (ESDS)
• LEED for commercial, residential and existing buildings, and neighborhood development.
• Washington Sustainable Schools Protocol

Washington has covered most every aspect, but I think their standards could be tighter.

How west coast green building codes should evolve

My wish for building codes is to make them mandatory with no opt-out feature, and apply them to new construction, renovations and repairs on residential and commercial buildings. There should also be standards for going beyond the code, which energy conscious designers and builders want to do. All in all, though, the west coast has caught on and is moving forward.

A big thank you to Rob Jones for hiring me in February and for giving me ideas and inspiration when I was dry throughout the year. Our emails are worth reading over just for entertainment!

Here’s my end-of-year wrap up with my five most favorite posts on the BuildDirect green blog. For my wrap-up of the BuildDirect blog, read this. (I’ll link this when the other one is scheduled.)

1. Green Housing Developments: 3 To Watch

As I researched green housing developments, I realized this was a topic worth more space than a blog post! I could write a book about the various ways developers are getting creative to cut emissions and build with a lower impact than they’re used to. I was impressed, because, truthfully, I am not fond of developers, who typically tear up beautiful open space to build something as cheaply as possible to reap the greatest profit. Nice to know it can be different.

2. Vertical Farming – The Food System of the Future?

Last spring, on my own blog, I wrote about a friend’s vertical garden. For people with limited space, growing up instead of out makes a lot of sense. You can plant and harvest more, since you can plant closer together, and crops are not sprawled all over a row. When I read in depth about vertical farming for this piece, though, vertical farming turned out to be a futuristic, sci-fi idea that I could not grasp. Find out why, and be sure to read the comments!

3. 10 Shipping Container Buildings For Homes And Outbuildings

I had a personal story to start this piece off. Again, the more I researched and read, the more creative answers there were. My partner and I are talking about building a house, and I suggested recycling some shipping containers. He’s thinking on it.

4. Green Jobs: Green Roofs and Roof Gardens

In this series on green jobs, I was compelled to write about gardening. Roof gardens replace the footprint of the building provide insulation, help manage storm run-off, and provide wildlife habitat. I knew all that. What I didn’t know is that a green roof has to be engineered! It is quite a process to design to carry to weight of soil, water and plants.

5. Green Building in Africa

The most humbling post I’ve written is about green building in Africa. As I read about the strife and politics of this huge continent, I had to wonder if green building was even a priority when sometimes, any kind of shelter would suffice. I felt helpless and as though green building was stupid and irrelevant. I have never studied Africa, so this was an eye opener to get right inside some of the countries. There is some green building going on in some of the more advanced countries, though.

Happy holidays, and here’s to another year of learning by writing for BuildDirect!

Prefab housing means less waste, less impact

Prefab building is done in a factory, and sections are shipped to the building site to be assembled. Construction in a controlled environment reduces time and money lost to bad weather and delayed shipments. There is less waste, since materials can be purchased for many projects, and this also saves money. Because there is not a lot of construction equipment at the site, there are fewer negative impacts on the land.

Prefab building is not new. Modular and manufactured homes are prefabricated, but now designers and builders are adding green features to make them energy efficient and more desirable.

Illustration of proposed Germantown, Nashville, TN prefab housing project. (image: David Hunter)

Prefab housing construction options to consider

Here are a handful of green prefab homes I found that would suit our needs, but, believe me, there are many more!

Green Modern Kits Passive solar and thermal mass, SIPs, off-grid options, water catchment

Eco Structures LEED certified, sustainably harvested wood for cabinets, passive solar, super insulated, recycled materials

Fab Cab Universal Design, energy efficient, sustainably harvested wood, SIPs, low VOC paints and finishes, recycled materials, water efficient fixtures

ARKit Optimized building envelope, sustainably managed and harvested wood, low lifetime operating costs, designs for residential, offices, hotels, studios and urban infill

Michael Jantzen’s Homestead House Recyclable steel, strong, adaptable, portable, passive solar

Blu Homes Element Natural light, passive solar, no wasted space in floor plan, sustainably harvested woods, low VOC paints

Cottage in a Day SIPs, exceeds Energy Start and LEED requirements, durable materials

Prefab housing becoming more commonplace

As people become more aware of how to tread lightly on the planet, they will choose green prefab housing. The options are unlimited to perfectly suit a building site, budgets and personal needs. Energy prices are unstable, and an energy efficient prefab will be a buffer against price increases, which will bring a higher return on investment. I think green prefab housing will become more commonplace once the housing market picks up again.

Look at me! Even a designer is turning to prefab!

What are green housing developments?

Green housing developments:

• are environmentally conscious with energy efficient homes, recycled materials, native landscaping, water conservation measures
• care about their occupants with affordable price tags and necessary services
• can be walkable communities, close to all conveniences
• can be transit oriented, close to public transportation
• might offer food security with on-site gardening and farming
• might revitalize downtowns that have been forgotten about
• can be built on old brownfields

Like anything earth friendly these days, green housing developments and communities take care of the planet and its people.

Here are three that won my heart.

***

1. Armory Park del Sol, Tucson, AZ

I spent about ten winters in Tucson, Arizona, and my favorite part of the city was downtown. I always lived near that area. It was convenient to the food coop, the library and city parks for my kids. We walked most everywhere.

Armory Park is an historic neighborhood, and Armory Park del Sol is part of the Tucson downtown revitalization. This development was built on the former site of South Pacific Railroad executive homes, and it used the existing infrastructure. This reduced construction costs considerably, aside from recycling! Urban infill is a better way to build than starting fresh on a new lot.

Amory Park; sustainable building with a small town feel. Photo: blasshomes.com

The development is made up of single family, net zero homes. That means they produce more energy than they use. Each home has a solar array on its roof, and they qualify for local, state and federal rebates and tax credits.

The homes are made of concrete, which acts as thermal mass. Energy efficient heating and cooling systems, water saving appliances and tankless water heaters reduce emissions and keep bills low.

The interiors are universal design, allowing for homeowners to grow old here. Paths, doorways and halls are wide enough for wheelchairs. There are roll-in and walk-in showers as well as grab bars on the bathroom walls.

The exterior design of these forward thinking homes matches the historical architecture of Armory Park. Old and new are beautifully blended. This is a place where I could retire!

2. The Navy Yard at Noisette, North Charleston, SC

When I lived in Portsmouth, New Hampshire in the 80s, a group of us tried to get the Portsmouth Naval Shipyard closed down and turned into much needed affordable housing. When I came across the story of this recycled navy yard, I felt we were on the right track back then.

In the 1890s, the Olmstead Brothers (designers of Central Park in NYC), had created beautiful and popular gardens at the mouth of the Noisette Creek in South Carolina. In 1902, President Roosevelt deemed it a good place for a naval shipyard. Charleston Naval Base was one of the most active bases of the 20th century.

In 1995, Charleston was abandoned along with many other shipyards (but not Portsmouth). In 2005, The Noisette Company bought the northernmost 340 acres for adaptive reuse.

Noisette North Charleston; one of the largest sustainable planned communities in the United States. Photo: DWHAdvisors.com

The base commander’s house, built in 1906, is being historically renovated for meeting spaces, classrooms and residential units. The medical officer’s quarters, built in 1917, will become an art and furniture showroom. An industrial warehouse is home to an arts and design center. Other buildings currently house restaurants, non-profits, offices and retail.

All buildings are passive solar and of sustainably harvested wood. Other features are zero VOC paints, low-flow toilets, waterless urinals and motion-sensitive lighting. Several buildings will achieve LEED Silver certification.

A riverfront park and creek preserve honoring native ecosystems and maintain biodiversity.

Again, like Armory Park del Sol, The Navy Yard is the perfect blend of history and technology.

3. Statice Heights, Capetown, South Africa

The Peace Garden in Statice Heights, Capetown South Africa. Photo: greencommunities.co.za

To create a better quality of life for the residents of Statice Heights, a 236 home pubic housing development, the city of Cape Town decided to green up the grounds. By beautifying the area, the city gives residents a sense of pride about their community. Gardens will feed all residents and give them food security. These urban gardens will also help alleviate poverty and bring people together towards one cause that benefits all.

Cape Town efforts will offset climate change. Recently, summers have been hotter, and winters have been wetter. Officials are addressing flood management and soil erosion by planting native trees and shrubs in each yard. Lawns will reduce run-off. Native plantings and open green spaces reduce the heat island effect and are aesthetically pleasing.

Aside from environmental improvements, the city wants to reduce poverty. Some residents have been trained to be solar installers, and others are involved in manufacturing park equipment to be installed throughout the area.

Statice Heights is a work in progress. Future programs include recycling, a community park with nature trails, and solar power and water catchment for all homes.

***

I love the energy efficiency of Armory Park del Sol, the renovations of historical buildings of The Navy Yard, and the environmental conservation and job training of Statice Heights. These are three housing developments that are environmentally conscious in three different ways!

Photo:buildingscience.com

As I started researching advanced framing, or OVE (Optimal Value Engineering), I found a lot of technical data and wasn’t sure how to present it. This opening paragraph of an article at www.buildingscience.com summed it up for me:

The current industry standard wall – a 2×4 frame at 16-inch centers with double top plates, three stud corners, jack studs, cripples and double headers – is being replaced by a 2×6 frame at 24-inch centers with single top plates, two stud corners, no jack studs, no cripples and single headers (and in many cases no headers at all).

It’s more detailed than that, but this was a good place to begin to understand the premise of cutting back on lumber without sacrificing structural quality.

Optimal value engineering history

OVE is not new. In the mid 1800s, it was called in-line framing. Rafters, joists and wall studs were all placed on 24” centers, and they lined up with each other. Somewhere along the line, we started framing walls and floors at 16” centers, which meant double top plates and headers over windows and doors were needed to carry the load.

Going back to 24” centers means the load is transferred from roof rafters to wall studs to floor joists. Only a single top plate is necessary, and headers are needed only in load-bearing walls.

In the 1970s, the National Association of Home Builders Research Foundation studied which framing components were not structural and could be eliminated. OVE was born! It creates an energy efficient building envelope that uses less material, which means less waste in our landfills.

Benefits of optimal value engineering advanced framing

• 5-10% less board feet of lumber
• 30% fewer pieces of lumber
• 60% more wall cavity available for insulation
• reduces thermal bridging saving energy for heating and cooling
• easier to design in multiples of 4
• less work for framers loading, unloading and building
• reduces labor costs
• fewer holes to drill for drywallers, plumbers, HVAC specialists and electricians

By framing a wider module, less lumber is needed and more space is opened up for insulation. The more insulation a home has, the more energy efficient it will be. When a wall stud meets the outside wall, there is an opportunity for air movement, letting heat out in winter and in in summer. This is thermal bridging. The fewer studs there are, the less air movement there will be. Insulated sheathing used on the exterior of the building will further reduce thermal bridging and increase energy efficiency.

Headers are only needed in load bearing walls, and they should be insulated with foam board between two pieces of wood for energy efficiency. Cripples are not necessary underneath windows, and window and door openings can be aligned with studs on 24” spacing. Roofs are trussed, not framed, saving on materials and labor. The traditional 3-stud corner is reduced to two studs. Clips or scrap lumber are used for attaching drywall, instead of that third stud.

Advanced framing and floors

Floors can be framed with I-joists for a stiffer, sturdier floor using less material. To reduce lumber further, a home can be built on a poured slab, which eliminates all first floor framing and a wood subfloor.

With less lumber, and fewer nails are used. Reducing the embodied energy of materials saves natural resources and is environmentally friendly. According to energysavers.gov, the approximate savings on materials for a 1200 sq ft house is $500, and $1000 for a 2400 sq ft house.

Better use of natural resources

Saving lumber is synonymous with saving forests. Trees are important globally, because they take CO2 out of the atmosphere and turn it into oxygen. If people realized the major role trees play, they’d be more hesitant to cut them down without replacing them.

I have written about other building methods that use little or no lumber, but sometimes there is no choice. If you need or want to build a stick frame house, please consider advanced framing. Interview contractors to see if they are very familiar with this method. Find out how many houses they have built this way. One source said five would make a builder feel comfortable with it.

Not all aspects of OVE need to be used, though. Parts of it can be implemented while building conventionally at the same time. This is actually a great way for a contractor to break into using OVE. I personally think they should learn it to conserve resources and build energy efficient homes.

Illustration: homebuilding.co.uk

All green building materials are meant to save energy and natural resources, reduce emissions and create a healthy living environment for the occupants. Insulated Concrete Forms (ICFs) go one step further to reduce build time and maintenance.

Building with ICFs is a one-step process to create walls for the building envelope, foundation and floors. The final product is a sandwich of two layers of polystyrene insulation and a concrete filling. There are no wall cavities to insulate. Interior and exterior walls can be finished once the concrete is poured. Compare that quick process to framing a wall, insulating it, and putting up and finishing drywall inside or applying siding outside!

How insulated concrete forms are constructed on-site

On the job site, polystyrene forms are put in place with steel connectors as interior and exterior walls. They can be dry-stacked (they connect sort of like Legos®) to the desired wall height, and rebar can be added for strength. Concrete is poured in 1’ at a time and tamped down to release air pockets.When the forms are filled, the walls are complete!

It will take a week for a foundation wall to cure enough for backfilling, and it will take several weeks for the walls to dry. In the meantime, the interior of the home can be very humid.

Other benefits of ICFs

• fire, wind, insect and mold resistant
• no rotting
• acoustic qualities
• reduce temperature fluctuations indoors
• no CFCs
• no wood used
• non-toxic – no off-gassing

ICFs: upfront costs and long-term savings

ICFs sound like the perfect building system, but it does have its drawbacks. Moving windows and doors after construction or to remodel takes masonry cutting tools. Remember, the walls are solid concrete! Like most green building methods, construction costs are a bit higher, maybe 5%, but the energy savings of an ICF home will pay for that.

The public needs to be aware of the money they will save by living in an energy efficient home. This information is crucial to getting people to embrace green building. Contractors and architects have modeling software that show the savings of a green home over the exact home built with traditional methods. When people can see a chart or graph of what they will save and their ROI (return on investment), they would scoff at the slight extra cost to build with energy efficiency in mind.

But back to ICFs now.

Insulated concrete forms systems: Rastra

There are various systems for ICF building, the first of which was Rastra. In the late 1960s, BASF, a German based polystyrene producer, was experimenting with expanded polystyrene beads mixed with cement, to sort of combine the traditional components of an ICF wall. In 1972, this became known as Rastra, a Compound ICF.

A few years ago, my contractor friend, Jimmy, was building a courtyard wall in my neighborhood. I saw him while I was out walking and went over to say hi. He and a worker were easily lifting a big piece of concrete-looking material off their truck. It looked like a very long, rough cinder block with several holes along the length of it. Then the worker measured it and cut it with a handsaw!

Photo: ownerbuilderbook.com

I asked Jimmy what it was. He said, ‘Rastra block.’ I’d never seen it before, but he explained to me that it was recycled insulating material mixed with cement, making it a lightweight, insulated building material. I was fascinated! He said they cut the pieces to the exact length they needed, stacked them, then filled the spaces with concrete for stability and structure. He said it went up quickly to reduce building time. I could see it was quicker than adobe or concrete block, which is standard for courtyard walls here.

Rastra block components

The Rastra website says their product ‘is made of a lightweight composite material called THASTYRON, produced with 85% recycled expanded polystyrene (Styrofoam) and 15% cement.’ I love that it’s recycled material! The materials for a Rastra home have a low embodied energy. I also love that Rastra walls have an R-value of 48 and reduce thermal bridging, which is where heat loss in a conventional home occurs.

Like I said, there are many ICF systems, and Rastra claims to be the original. If you want to build with ICFs, do some research, ask a lot of questions, but most important, find a contractor that works specifically with ICFs.

According to the US Environmental Protection Agency (EPA), buildings in the US account for:

•  39% of total energy use
•  12% of the total water consumption
•  68% of total electricity consumption
•  38% of the carbon dioxide emissions

States and municipalities are rewriting building codes to help improve those figures, and architects are learning to design with energy efficiency in mind. Some day, we won’t say ‘green building’, because all buildings will be low energy users.

Photo: Giulio Pepe

There’s a wealth of green job opportunities

President Obama’s Better Building Initiative would create thousands of jobs that would retrofit commercial buildings to be more efficient. Tax incentives, loan guarantees and grants to help rewrite building codes, regulations and performance standards could also fund thousands more jobs in the construction industry.

Green construction jobs and careers are more extensive than just putting up walls and a roof. A partial list of green jobs includes:

•  electrician
•  machinist
•  painter
•  energy auditor
•  plumber
•  LEED project manager
•  home retrofitter
•  weatherization specialist

Some of these require a college degree (managers), while others require special training and licensing (plumber, electrician), and others need no formal training at all.

How to get started in green construction

Now is the time to get an education or work experience in green construction, since that knowledge will be in high demand when the industry gets rolling again. There are workshops, internships and apprenticeships as well as degree programs at universities, community colleges and vocational schools.

Some jobs can be learned with on-the-job training. Even though construction is slow right now, hands-on training is the most effective way to learn the trade. Basic construction knowledge is imperative to specialize in building with natural materials, such as strawbale or adobe. An apprenticeship with a green builder is more practical experience that will be in high demand later.

Photo: Combined Media

Look to the US Green Building Council (USGBC) and the Sustainable Buildings Industry Council (SBIC) for training programs. Trainers are needed, too! This takes some qualification, but green building experience in a down market can be advantageous for training the future workforce. Scour job boards for a green construction job.

I have a great example of how contractors need to be educated. When I remodeled my house in 2007, I hired a contractor that ended up knowing nothing about passive solar, low-e windows, green materials or even low-flow toilets. I gave him my design, and he drew it to scale and took care of the details, but when it came time to buy materials, or over-insulate the ceiling, I had to teach the crew about green building. Contractors need to learn these things to stay competitive for the future economy. Who is going to hire that company to build for them if they don’t know how to create an energy efficient space? No one.

Now is the time to break into the green construction field. Figure out what you want to do, find some training, get some work, and be prepared to make a difference in the green economy that’s on the horizon.

What is a green job?

According to the United Nations Environment Program (UNEP):

We define green jobs as work in agricultural, manufacturing, research and development (R&D), administrative, and service activities that contribute substantially to preserving or restoring environmental quality. Specifically, but not exclusively, this includes jobs that help to protect ecosystems and biodiversity; reduce energy, materials, and water consumption through high efficiency strategies; de-carbonize the economy; and minimize or altogether avoid generation of all forms of waste and pollution.

The housing industry fuels the economy. To create green jobs could pull us out of this slump and reduce our independence on foreign oil and other fossil fuels. According to the EPA, buildings consume about 1/3 of the electricity in the US, so energy efficient upgrades are a smart way to start saving money and energy. This will train workers and create jobs, careers and businesses. The green economy is the future!

Green jobs stimulus in U.S cities

The stimulus package helped fund energy efficient retrofits of commercial buildings, with the idea that energy savings would allow business owners to hire employees. Energy savings and job creation – win/win!

The Dept. of Labor recently awarded an $8M grant to Jobs for the Future for training in green building, auto technology, manufacturing and utilities. This will help Detroit, Philadelphia and Washington DC with green job creation and training in the construction industry.

In Detroit, hit hard by the recession, numerous foreclosed and abandoned homes will be renovated and upgraded with energy efficient features. Funds for DC will also go towards weatherization, solar installations and green roof maintenance, and will create jobs with several construction unions. Philadelphia’s solar industry will benefit.

Green jobs sector programs

Green For All is training young people in low-income communities in solar, weatherization, auto technology, construction, and mass transit to help get them out of poverty and be able to equally compete in the job market.

‘Green For All is a national organization working to build an inclusive green economy strong enough to lift people out of poverty.’

Green City Force is training urban youth to create a ‘green city’. In their first year, they put reflective coating on 500,000 square feet of city rooftops to reduce the need for cooling energy. They were also involved with New York’s Weatherization Assistance Program (WAP) conducting energy audits.

The Green Jobs-Green New York Act was passed in 2010 to offer financing for energy efficient upgrades that will pay for themselves. A loan is acquired by the building owner and repaid through on-bill financing, an extra charge on the utility bill. One million homes and business will be able to be retrofitted through this program creating thousands of jobs.

Green building industry job creation strategies

Thousands more jobs could be created through:

• The Better Building Initiative, which would improve energy efficiency of commercial buildings by 20% by 2020
• A change to the current tax incentive for energy efficient retrofits of commercial buildings
• A federal loan guarantee program for energy efficient upgrades
• Grants from the Race to Green program for local and state governments to upgrade building codes, regulations and performance standards

Most colleges and universities now have degree programs in sustainability to train the future workforce for a green economy. Students want meaningful careers to reflect their eco-conscious lifestyles.

You can find higher education for these green construction careers:

• interior design
• architecture
• space planning
• landscape architecture
• natural building
• energy – solar, wind, geothermal
• energy audits and weatherization

Looking for a job in the green sector?

Aside from energy efficient retrofits, green collar jobs in construction include solar installation, weatherization, water-wise landscaping, building green rooftops and building wind farms.

Here are a few sites I recommend if you are green job-hunting:

• SustainableBusiness.com
• The US Green Building Council (USGBC)
• Dancing Rabbit
• Renewable Energy World
• Green Careers Guide

As we get back on our feet financially, the green job sector will blossom and thrive. It will be a slow process, but investing now in the future green economy is win/win, as we save money and natural resources, reduce emissions and put people to work.

Photo: Derek Harper

Twenty years ago, a friend of mine told me he was building a one-room cabin for himself. I went to his remote, sagebrush-covered land to see what he was doing, because I had seen a few of his other inexpensive, one-of-a-kind homes before. He’s a resourceful guy, building from scraps and recycled materials. Leading a simple life and traveling quite a bit, he just wanted a simple shelter to spend summers in Taos.

The walls of his current project were solid yet rugged, uneven mud and only about 3’ high. I had no idea how he accomplished that. He said he was just piling mud on top of itself to create a single, round wall. There was an opening for a door and the bottom of a window frame was in place. The structure was going to be tapered to the top like a huge beehive. I thought he was very creative with his building method and was totally fascinated! Later, I learned this type of construction has a name – cob.

Cob construction is eco-friendly

Before there were adobe bricks, there was cob. There is no distinct era when cob was developed, but it is quite well known in the UK, where cob homes built in the 1500s are still inhabited. Taos Pueblo, probably made with the cob method of piling mud on top of itself to create walls, has been continuously inhabited for over 1000 years. Most likely there are older structures, since mud was one of the first building materials.

Reasons that cobbing is an eco-friendly building method:

• Local materials – You can’t get more local than the soil from the land where the structure will stand. There are no transportation costs, no emissions, no manufacturing and no toxic chemicals to off-gas.
• Natural materials – Clay soil is mixed with sand and straw, more natural materials.
• Low tech - Traditionally, the mix was made by stomping it with bare feet or oxen. Today, the mixing is done with machinery, making it less eco-friendly, but some diehard cobbers still stomp.
• No waste – You make as much mix as you need. Extra goes back to the earth or it gets used for relief designs.
• Heating and cooling – Cob is excellent thermal mass for passive solar homes. It stays warms once it’s heated, and buildings stay cool in summer.
• Fire resistant – This is a natural feature of mud construction, making cob suitable for hornos (outdoor ovens) and chimneys.
• Community – Cobbing is a wonderful way to get friends together to connect and make short work of a big project.

There are personal and spiritual benefits, too:

• Cobbing is an excellent DIY project. You become self-sufficient and empowered when you build your own shelter.
• It is inexpensive. This is an effective way to build if you have lots of time and land, and little money.
• You can get creative in your design and details, building curves and sculpting organic shapes. Think Gaudi!
• The repetitive and slow process of cob building can be very meditative and expanding. Simple tasks like this allow your mind to wander, which lets you sift through and sort your world.

Green construction process with cob

The foundation for a cob building must be away from low areas where water could run or settle. It should be of a non-porous material and above ground 8-12”.

When building the foundation, you first have to know how thick the walls will be. Traditionally, cob walls were anywhere from 20” to three feet thick. Today, wall thickness averages 24”.

Photo: janetcetera

The word ‘cob’ is Old English for lump or rounded mass. You make the mixture by stomping the materials together on a tarp. The final product should be very sticky, yet pliable – a ‘lump’. It should be able to be formed into a ‘rounded mass’ without losing its shape. These masses are laid on the foundation layer-by-layer and tamped down by hand to fill any spaces below. The final result should be like one solid piece of mud, not separate pieces simply placed on top of each other.

Layers can be 6” to a foot high, or whatever height will dry quickly in your climate. Each has to dry before the next is applied. If rain threatens, put a tarp over what you have completed.

Once the walls are built, the roof should be pitched with large overhangs to protect your hard work from rain. Consider that 600-year-old cob homes in the UK are still standing, and the UK is a wet place! Thatched roofs have protective overhangs.

Cob is a porous material, and it does absorb water. It does not erode, though, because a wall that thick will not become saturated. However, it needs to breathe to dry out, and that is why cob should not be stuccoed.

To me, the most appealing aspect of cob construction is that, when you are done building, you have a unique home like no one else’s. You can create built-in walls and benches, and you can sculpt custom designs on interior and exterior walls. Or you can build a single room with a door and a window, like my friend out on Taos mesa. I bet there isn’t another one like it!

Stay tuned for green building with earthen homes, pt. 3: rammed earth homes.

Prefab homes have had a negative associations attached to them; unglamorous, characterless, low-quality, temporary. But in addition to the falsehood of these associations, as it turns out, they are actually coming into line with a new paradigm for green building. Fashioned in modular processes offsite, and then delivered to a location, a pre-fab home is less instrusive to an eco-system, and less fuel is burned to build them, due to fewer trips to the site.

But, what are the advantages of a pre-fab home beyond these implications for green building? Does its nature as an eco-friendly housing construction method really mean a sturdy, long-lasting, and affordable home in which you can place your trust? Writer Nadia Jones explores these questions below …

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In many ways, prefab homes get an unfair label. Many people don’t believe that they can get the modern and unique design they desire with a factory made, pre-designed home. While in the past this may have been true, companies throughout the nation are working to reinvent the industry of prefab housing.

Prefabricated homes were once used predominately in underprivileged areas for track housing or project homes. However, in recent years prefab housing has made a major market shift. Prefab homes now strive to be the future of the housing market. Offering amazingly beautiful, modern architecture, fairly inexpensive prices, and eco friendly living, prefab homes may be exactly that: the future.

Prefab does not mean ‘cheaply made’

Many individuals hear the term “prefabricated” and immediately think “cheaply made”. This, of course, is not the case. Prefab construction begins in a factory. Components of a structure are manufactured offsite in an industrial facility and then shipped to the building location to be fully erected there. In many ways, building a home within a controlled factory environment allow builders to do an even better and more thorough job.

This is the site of a modular building project in Denmark, built well, inexpensively, and with a community feel in mind. Click the photo through to the photographer's page to learn more about how it was made. Photo: seier+seier

Because structures are built offsite and indoors with controlled conditions, the materials used on the house are better cared for. By eliminating weather as a factor during the construction process, building materials arguably stay in better condition when they are at their most vulnerable. Encouraging quality construction, prefab homes are specifically designed to withstand common weather conditions. Once delivered and erected on site, they are built to last as long as a traditional home.

Prefab homes demonstrate modern design aesthetics

While home prefabrication is not a new concept, the design styles being used on these homes has changed drastically in recent years. Designers have worked hard to create a new aesthetic for prefab homes and with that new aesthetic bring new life to the phrase ‘pre-fab home’. The new aesthetic that many pre-fab housing companies are striving for features clean lines, simple architecture, and a modern glitz factor.

Pre-fab homes have found their niche among modernist bargain shoppers with a desire for eco-friendly living. Modern prefab homes feature maximized natural light with numerous windows placed depending on the individual location of each structure. This gives the home a beautiful look as well as an opportunity for passive heating and cooling, minimizing the need for high energy costs.

Prefab homes and affordability

With modern design and green initiatives in mind, it can be hard to believe that pre-fab homes are in any way affordable. However, that is exactly the point. New prefab home developers strive to make expensive looking, modern homes that are better for the environment at a price that is accessible for the average person. Mass modular construction, mobility, and versatility make pre-fab homes inexpensive and in reach.

With fewer materials used, the cost of building a prefab home is less. Also, prefab homes take a fraction of the time to design and manufacture because they are created within a controlled environment, cutting the cost of labor significantly. In other words, pre-fab homes can be built more quickly and at a lower cost.

Prefab homes and green building materials

Another way that prefab housing companies promote modern and green design is in the materials they use. Many builders use as many recycled and renewable products within their homes as they can. One go-to material for green builders is bamboo. Because bamboo grows so quickly and easily, it is a great renewable resource to use in flooring and other design elements of a home.

This is a shot of a modular home, built by students in 2007 as a part of a sustainable architecture course. BuildDirect supplied the strand-woven bamboo flooring you see here.

Also, using steel, wood, and cement as sturdy framing materials helps homes withstand difficult conditions, accounting for less waste in the long run. Furthermore, builders constructing homes or parts of homes within a factory are able to reduce the amount of material waste by a significant amount. Less waste means a greener home.

Gain Eco-friendly awareness

While prefab housing may not be for everyone, there is a lesson to be learned from the prefab, eco-friendly approach. Even if you do not desire a home that is built in a factory, there are plenty of lessons to be learned from building cheaply and intelligently with the environment’s well-being in mind.
Consider recycled or renewable materials for your next project. Think about reducing your energy use by positioning windows in opportune locations based on the location of your home. All of these things can help to save you money and help to save our world.

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Thanks, Nadia!

Nadia Jones blogs at top online college about education, college, student, teacher, money saving, movie related topics. You can reach her at nadia.jones5 @ gmail.com.