Reducing the Environmental Impact of Construction

There's no doubt that construction has an impact on the environment. How much impact depends directly on the builder and the steps they take to minimize that impact.

From spreading straw on all of the disrupted soil to protecting storm water run off drains there are a number of opportunities to reduce the impact.

One of the many steps Miranda Homes takes is to use an Eco-Pan. During the pouring of the foundation the pump truck and the concrete trucks need to wash off the residue of concrete before it cures and makes cleanup much more difficult. A common practice is to wash off in the street or onto an unused piece of property. “Wash-out water with high pH is the number one environmental issue for the ready mix concrete industry,” according to Richard Morris of the National Ready Mix Concrete Association.

To stop this wash-out water from contaminating the environment we use an Eco Pan to contain all of the residue that is washed off of trucks and tools.

Prior to pouring, the Eco Pan is delivered to the job site and set in place. After the pour it is picked up and the contents are cleaned and recycled. By using an Eco Pan we are able to stop about 100 gallons of water and concrete from going into storm drains or directly into the soil. Hopefully we'll see more and more builders using them.

We'll post details on some of the other steps we take to minimize the impact of construction in future articles. In the mean time, let us know if there's any topics you'd like us to cover.

Mark Mecklem - Miranda Homes

Revised Blower Door Test Results

Last week we posted the results of our blower door test.

As promised, we had Earth Advantage out for another test after taking some measures to further seal up leaks in the house.

MacKenzie Winchel came out to perform the test. After running it three times to make sure the results were correct, she reported a result of 0.6 ACH 50/PA!

There are really three secrets to achieving this kind of result. Come to one of our open houses and we'll tell you exactly what they are!

Mark Mecklem - Miranda Homes

Monolithic Foundations

We've completed another monolithic foundation pour. A "monolithic pour" means that all of the foundation concrete is poured at one time.

There are two main benefits to working this way. One is that the resulting foundation is much stronger than one that is poured in stages. Rather than a break between each stage, a monolithic foundation is one cohesive piece. The second benefit is that the concrete pump truck only needs to make one trip to the job site rather than three. At a cost of about $600 per visit, it saves a substantial amount of money, not to mention fuel, emissions and labor to have the pump truck come out one time.

As mentioned in an earlier post, we use a CertainTeed product called Form-A-Drain that acts as both a footing form, and a radon gas and water drain for the foundation. By using special brackets designed by our engineers we are able to perfectly space the footing forms, hold the re-bar in place and support the Logix Insulated Concrete Forms (ICF) for the foundation walls. ICF Blocks” are factory molded expanded polystyrene forms that are left in place after the concrete is poured for a foundation or wall. One of the benefits of using “ICF” block is that the resulting foundation is insulated, eliminating the need for external air vents that transfer heat and allow pests to enter and exit the foundation. The system has been incorporated in everything from foundations like ours to complete concrete buildings.

Logix ICF blocks fit together quickly and easily to create foundation forms that are the correct width consistently throughout the foundation. The blocks support all of the rebar required by code and connect to each other creating a single pour form that increases strength and decreases labor. The outside of the foundation can then be finished with stucco, siding, or stone for depending on the look desired. Read more about Logix at www.logixicf.com

After pouring the footings and ICF forms we finish up with an Earth Slab. (Stay tuned for more about the benefits of Earth Slabs in a future post about conditioned crawl spaces)

Mark Mecklem - Miranda Homes

Solar Panels - A bunch of Hullabaloo?

We've been trying to figure out what all the hype around Solar Panels is about. It can be tough to get good solid answers about how much energy a homeowner can produce and store, how much it costs to do it, and how much that all offsets their reliance on "the Grid."

Click HERE to read an article from "How Stuff Works" and let us know what you think.

Mark Mecklem - Miranda Homes

Footing Forms

In the following weeks we'll be publishing articles about the construction of one of our homes. The model we'll be highlighting is the Mountain View. We'll be posting the latest progress with pictures and talking about some of the methods and materials we use.

The excavation for this House has been completed and we have installed the forms for the footings using Form-A-Drain; a product from CertainTeed that we use for its environmental qualities. Form-A-Drain is made from 100% pre and post-consumer recycled PVC. It also provides a permanent solution for venting of radon gas and for the redirection of ground water away from the foundation of the home.

One of the big advantages of using Form-A-Drain is that the footing forms don't need to be stripped after pouring the foundation. They serve a dual purpose. As you'll see later on, they're part of our monolithic pour that forms a strong one piece foundation. Using a form that stays in place as the foundation drain system eliminates wasted time, materials in landfills and trips to the job for our crews and concrete trucks.

In addition to the Form-A-Drain we use brackets designed by our engineers that spread and secure the forms to the precise width required while also supporting the ICF Block and suspending the steel reinforcement at the proper height. They too stay in place after the foundation is poured.

For more information on Form-A-Drain, please click here.

Next step: Logix Insulated Concrete Forms for the foundation walls.

Mark Mecklem - Miranda Homes

Another Blower Door Test

Earth Advantage Technical Specialist, Joel Tolman came out yesterday to do a final inspection and Blower Door Test on another of our homes. The Blower Door Test measures how well a house resists infiltration of outside air. Infiltration typically represents 20-40% of the cost of heating a home so stopping as much of it as possible is an important step in reducing energy use.

To perform the test an exterior door is opened and sealed with a panel that includes a large fan. Negative pressure is created inside the house by blowing the air out. Using an electronic sensor, the tester can then measure the amount of air that is able to infiltrate through windows, doors or any other breach points. Performance is determined by how many times per hour the air in the house changes over. The lower the number is, the better sealed the house is.

The typical house, built to current code, usually scores 10 Air Changes per Hour (ACH). To qualify for the Energy Star rating a house can score no higher than 7 ACH. A better than average score falls in the range of 3 to 5 ACH. Our house scored 1.6 ACH.

Even though we've scored so well we were able to identify some of the areas we had breaches. We'll be asking Earth Advantage to come back next week to measure again and the new home owner will be in attendance.

Mark Mecklem - Miranda Homes

Sold!

The River View is sold!

The next available home is a Mountain View.

See it at www.mirandahomes.com in the "Floor Plans" section.

Mark Mecklem - Miranda Homes

A Great Article on Insulation, Infiltration and the Stack Effect

This is a great article about building science and air flow. It supports the use of spray foam insulation, conditioned crawl spaces and exterior vapor barrier insulation. It's worth taking the time to read.

Click here or on the image above to read the full article.

Mark Mecklem - Miranda Homes

Video of Spray Foam Insulation

Have you ever seen spray foam insulation being applied. It's fascinating!




Mark Mecklem - Miranda Homes

Miranda Homes Featured in NuTimes Magazine

Miranda Homes is the subject of an article in the latest issue of NuTimes Magazine.

Click here or on the picture above to read the full article.

Mark Mecklem - Miranda Homes

How to Build Cars... And Houses.... And Houses out of Cars...

One of the benefits of our planning and pre-building process is that we can minimize the waste we generate. Not only wasted materials, but wasted time as well. We invest time up front on methods and processes that allow us to build efficiently like building the wall panels in the plant and delivering them to the site in the order we will stand them. We don't cut framing on site so there's not a big pile of lumber or steel scraps. The exterior rigid foam insulation is installed in the plant not hand-cut out in the field. We deliver the materials for each day's work in the morning and leave the job site clean at the end of the day. All this planning means there aren't extra parts, material or scrap sitting around on our job sites. It’s one of the remarkable things that people notice when they visit.


This way of working comes from the Toyota Production System (TPS). It’s called “The Five S’s.” They are:
• Sifting – Identifying the needed items at the worksite and removing the unneeded items
• Sorting – Arranging items at the worksite to be easily found and within reach when needed.
• Sweeping – Cleaning the area and around the worksite and cleaning the tools to maintain top performance
• Spic and Span – Providing a system to create a clean and safe work environment
• Sustaining – Creating awareness or discipline by each worker to maintain a clean and safe worksite.

The Five S’s are important because disorder can cover up problems and because they encourage prevention thinking.

Another positive result of the methods we use is a very clean job site.
We feel that it’s a good reflection on us and provides a safe work site for our associates and our visitors. Job site housekeeping is one of the major requirements in the General Safety and Health Provisions section of OSHA’s Health & Safety Construction-related Regulations. Even small obstacles can be a tripping hazard. Injuries from slips, trips and falls on flat surfaces account for a large number of the overall injures in residential construction.

Of course, an uncluttered job site is easier to work in too. Tools and supplies are visible, easier to find, and it’s easier to move around. Time isn’t wasted moving things out of the way before you can start the next task. A clean job site means that it’s easier to do even the small safety tasks that can make a difference like running our magnetic sweep around the site to pick up any stray screws that could pierce a boot or a truck tire.

Really, it’s just an extension of our quality-focused approach throughout the whole process. It includes all of the processes, the people, the methods and the end product.

Mark Mecklem - Miranda Homes