Great article (if we do say so ourselves) in the ESN today all about green building, advanced building science, and techniques that make homes more energy efficient.

http://www.delmarvanow.com/article/20100519/ESN01/5190361/-1/ESN

The Rayfield’s home is a great example of 21st century materials and techniques NOT dictating style or aesthetics. Their charming 18th century style home was fully certified by EarthCraft, Virginia. It is quiet, comfortable, and efficient to operate… quite different from the experience one might have had in the 1700’s. 

Between the EarthCraft program and the EnergyStar program, we did several tests that evaluated the efficiency of the home. A blower door test shows that if all the tiny pin size gaps or cracks in the whole 3000+ sq. ft. house were added up, the area would be less than 1 sq. ft.  That efficiency comes from the combination of advanced building practices and materials, such as: ICF- integrated concrete forms for the main structure, geothermal heating/cooling system, spray foam insulation on the gables and roof, efficient windows and doors, an ERV ventilation system, tankless water heaters, and EnergyStar appliances. Overall, the house is 40% more efficient than the ’standard’ home of the same size.

When you treat the house as a system rather than a set of individual parts, you end up with a better product. It’s a quiet, comfortable space which is relatively free from dust and bugs. The air quality is high and both water and electricity are well-managed. Utility bills are no longer a dreaded monthly event.

Add a wind turbine out in the field and the house could be off-the-grid… just like they were back in the 1700’s!

White ICF concrete-filled walls are clearly visible during construction

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In past newsletters, we’ve talked about Insulated Concrete Forms (ICF) as an alternative for a  conventional wooden framed home. As green building technologies continue to gain momentum, ICF is becoming a popular choice for building a new home.

Looking into an ICF formed wall

The Energy Efficiency Benefit – The most frequently discussed advantage to ICF is the increased level of energy efficiency.  ICF greatly improves the thermal envelope of a home with increased R-value and larger thermal mass.  In other words, an ICF home, which doesn’t have joints between walls and floors or wood in the walls, is extremely air-tight. Controlled fresh air is circulated in the home. As they say in the ICF industry, “Build it Tight, Vent it Right.”  This works to prevent conditioned air from escaping and unconditioned air from entering.  The ICF acts as a consistent and continuous insulator. Also, ICF homes create large thermal mass which allows them to ‘flatten out’ or slow down the daily temperature fluctuations. They absorb heat when the surroundings are hotter, and give heat back when the surroundings are cooler.  Over time, these energy efficiencies translate to lower utility costs for a homeowner. The additional up-front costs of ICF provide a financial payback over the life of the home. 

Other benefits of ICF include noise reduction, increased indoor air quality, durability in severe weather, and fire resistance. Most residents of ICF buildings describe them as very comfortable to live in.

The construction of an ICF home is fascinating to watch. One of our current projects reached the “pour” stage today. The ICF forms had been assembled on site as what looked like large styrofoam legos. The penetrations for electric and plumbing services were all precisely placed. The window and door openings were finished to the correct opening sizes. Today, the concrete was poured and vibrated into place.  Here are some photos:

View of a future porch entrance

View from inside the future rooms

The concrete pour

A very long boom delivers the concrete

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