Start-to-Finish LEED Home

Paul Graham sat down with me recently to discuss the metal roof StazOn Roofing put on this home. Midway’s metal roof  proves how beautiful this sustainable alternative can be.  Beauty isn’t the only appealing quality of the roof.   Homeowners with a metal roof report saving up to 20% on their energy costs.  Metal roofs reflect the sun’s radiant energy which in turn can reduce attic heat gain by up to 34%.  What a big deal in Texas!  Have you ever been in an attic in August?

According to the National Roofing Contractors Association, the popularity of metal roofing products has increased dramatically over the past decade, a clear sign that homeowners and builders are growing more and more aware of this product’s benefits.  Metal roofs are favored for their fire-resistant qualities, longevity, and speed of installation—in most cases, by a qualified metal roofing contractor.

BuildingGreen explains for a surface to stay cool, it needs two key attributes: reflectivity and emissivity. Reflectivity measures how well a material bounces back radiation.  But since all surfaces absorb some heat, we also need to consider emissivity, or how good a surface is at radiating heat back out into space.

The Midway house has a SRI of 68.  Solar Reflectance Index (SRI)  is derived from a calculation in ASTM E1980 which uses a roof’s solar reflectance, thermal emittance and medium wind coefficient to generate a unitless value from 0 to 100. The higher SRI values indicate a roof whose surface temperature is lower, thereby reducing heat gain into the living space beneath the roof.

StazOn Roofing is so convinced of the superiority of thier metal roofing systems, they back up their products with a lifetime limited warranty for a 40-year transferable warranty.

The Department of Energy states heating and cooling account for 50 to 70% of the energy used in the average American home. Inadequate insulation and air leakage are leading causes of energy waste in most homes. Insulation saves money and our nation’s limited energy resources makes your house more comfortable by helping to maintain a uniform temperature throughout the house, and makes walls, ceilings, and floors warmer in the winter and cooler in the summer.

Heat flows naturally from a warmer to a cooler space. In winter, the heat moves directly from all heated living spaces to the outdoors and to adjacent unheated attics, garages, and basements – wherever there is a difference in temperature. During the summer, heat moves from outdoors to the house interior. To maintain comfort, the heat lost in winter must be replaced by your heating system and the heat gained in summer must be removed by your air conditioner. Insulating ceilings, walls, and floors decreases the heating or cooling needed by providing an effective resistance to the flow of heat.

Insulation is rated in terms of thermal resistance, called R-value, which indicates the resistance to heat flow. The higher the R-value, the greater the insulating effectiveness. The R-value of thermal insulation depends on the type of material, its thickness, and its density. In calculating the R-value of a multi-layered installation, the R-values of the individual layers are added.

The effectiveness of an insulated ceiling, wall or floor depends on how and where the insulation is installed.

Classic Urban Homes has used three types of insulation to maximize comfort and energy efficiency.  The attic’s underside of the roof’s sheathing has a spray foam application to help with the performance of the HVAC system.  In Texas the ducts are in the attic.  In the summer months temperatures easy exceed 100 degrees outside.  When you turn the air conditioning on to get some relief from the heat  the cool temperature has to pass through the ducts in the attic.  If your attic is hot, your air conditioning has to work twice as hard and cold air is lost in transmission. By insulating on the underside of the roof sheathing we bring the ductwork into a conditioned space and almost eliminate heat gain through the air distribution system.  A further advantage is that duct leakage becomes less critical since these leaks are now within the conditioned space of the building.  Thats what I call a happy home!

Cellulose was used on the East facing wall to mitigate the sound from Midway.  Modern cellulose insulation is typically made with recycled newspaper using grinding and dust removing machines and adding a fire retardant.

Spray applied cellulose is used for applying cellulose to new wall construction.  This application uses a wet system where the recycled newspaper is mixed with a water mist to activate the self adhesive properties.

Fiberglass insulation was blown in the majority of the home, with R-22 value.  Fiberglass insulation products come in R-values ranging from R-11 to R-38 for fiber glass batts and rolls.  This particular application is installed with a Blow In Blanket System often referred to as BIBS.  Once the BIBS fabric is stapled in place,  a small hole is cut in each cavity to fit the hose of the blower.  Each cavity is filled with the fiberglass to capacity.  Once the house is complete, the  energy costs will be monitored to calculate the true savings of this green home!

Its been a while since my last post but the house has made a lot of progress!  With less than 30 days until Christmas I’m interested to see if the new homeowners will be in by then.    Its difficult to capture the true beauty of this house.  It does resemble the rendering exceptionally well though.  To view the complete photo album, visit Green Home Residential’s Facebook page.