Page 57 - Green Builder November Issue Codes Update

www.greenbuildermedia.com/energy-solutions-home

Case Study: Florida

The Florida Building Figure 1

Commission released a Figure 2

memo in April, Renewable Check out this video that details the issues surrounding Florida’s
solar-versus-high-performance stance. http://bit.ly/2cUx6AB
Energy Trade-Offs in the

Building Energy Code that

reviews what would happen

if on-site generation is

allowed for compliance in

the Florida Building Code.

FLORIDA ENCOMPASSES TWO CLIMATE ZONES for
purposes of building energy code compliance—Climate
Zones 1 and 2. For those climate zones, the IECC
establishes an ERI compliance target of 52. This target
was modified however, by Florida HB 535 to an index
of 58 in both climate zones.
If on-site generation is allowed for compliance in the
Florida Building Code, there is a very real possibility
that homes will be constructed that meet only minimum efficiency
standards and still meet the ERI target.
As Figure 1 illustrates, a home built in Tallahassee to minimum
2015 prescriptive standards and the 2009 thermal envelope standards
receives a failing score of 86. That same home with 5 kW of solar
panels (Figure 2) achieves a passing score of 45.
Allowing on-site generation to substitute for building energy
conservation has a number of negative impacts:
¦¦ Building envelope energy efficiency measures like insulation,
sealing and windows deliver efficiency for the life of the building.
In the case of sealing and wall insulation, these measures are
typically maximized at time of construction or the opportunity is
lost for the life of the building.
¦¦ Failing to optimize the efficiency of the building envelope means
a lost opportunity to reduce the size of heating and cooling
requirement and to reduce the solar PV system needed to meet
the home’s electricity requirements.
¦¦ A less energy efficient home translates into higher utility bills to
that homes occupants, even with renewable generation.

www.greenbuildermedia.com November/December 2016 GREEN BUILDER 55