Record Breaking Energy Performance

Eco-Panels recently assisted a homeowner build his home that obtained record-breaking energy rating numbers.  Here are excerpts from our marketing flyer.

International and National Green Building Programs Envelope Leakage Standards Compared to Prototype Home Built with Eco-Panels

Subject home:

Asheville, NC, USA (in the mountains)

IECC Climate Zone 4, elev ~2,200 ft or 670 meters

Area: 1,872ft², or 174m²

Volume:  21,453 ft³, or 607 m³

Construction Cost:  approx. $90/ft²


Note that Eco-Panels by design will make a building envelope very energy efficient.  Only minimal extra attention was required to receive this record breaking energy rating.



NC Healthy Built Homes:  North Carolina Green Building Program.  Uses ACH 50 

Prerequisite:  3.5 ACH or less                        Eco-Panels prototype:  0.48 ACH


Passivhaus:  This is the strictest residential certification in the U.S.  Uses ACH 50

Standard:  0.6 ACH or less                             Eco-Panels prototype:  0.48 ACH


Earth Craft House:  GA, AL, SC, VA, TN    Southface Institute.  Uses ELR

Standard: 0.4 ELR                                          Eco-Panels prototype:  0.039 ELR


Canadian R-2000:  Canada’s Green Building Program.  Uses ACH 50

Standard:  1.5 ACH or less                             Eco-Panels Prototype:  0.48 ACH


NAHB:  National Green Building Certification Program.  Uses ACH 50

Standard:  5.0 ACH or less                             Eco-Panels Prototype:  0.48 ACH



ACH at 50 Pa: The Air Changes per Hour (ACH at 50 Pa) is commonly used measure of building air tightness. ACH at 50 Pa is the number of complete air changes that will occur in one hour with a 50 Pascal pressure being applied uniformly across the building envelope. ACH at 50 Pa is a useful method of adjusting (or normalizing) the leakage rate by the size (volume) of the building.

ACH at 50 Pa = (CFM50 x 60) / building volume in cubic feet

ELR (envelope leakage ratio):  CFM50/square foot of surface area (ELR):  this is the measured CFM50 divided by the surface area of the building envelope. ELR is a useful method of adjusting (or normalizing) the leakage rate by the amount of envelope surface through which air leakage can occur.  Experience to date has shown that for buildings with a ELR above 1.0, very large cost-effective reductions in infiltration can often be achieved using blower door guided infiltration and insulation techniques. In buildings with a calculated ELR in the 0.5 to 1.0 range, it is often more difficult to achieve economical improvements in air tightness.

ELR = CFM50 / square foot of building envelope surface area


See the blog for this construction project at: