Performance vs. prescriptive path

Here are a couple ways you can reach compliance: performance path and prescriptive path. The performance requirements refer to the overall energy efficiency score, while the prescriptive path refers to meeting certain thresholds listed in your climate zone. 

The requirements you must adhere to will depend on your climate zone. There are three climate zones you need to pay attention to in the state of Pennsylvania: Climate Zone 4 (Southeast PA), Climate Zone 5 (Central PA), Climate Zone 6 (Northern PA). Philadelphia and Southeastern Pennsylvania are in Climate zone 4, Click over for the envelope requirements that apply.

Each climate zone has requirements the following:

  • Fenestration U-factor
  • Skylights U-factor
  • Glazed fenestration SHGC
  • Ceiling r-value
  • Wood frame wall r- value
  • Mass wall r-value
  • Floor r-value
  • Basement wall r
  • Slab r-value and depth 
  • Crawlspace wall r-value

You may have noticed that the requirements have become more stringent than the 2009 IECC regulations. This is because the Pennsylvania legislator is trying to progressively increase the energy efficiency of new homes being built and renovated. Some climate zones have also introduced solar requirements.

RAEP values indicate the thresholds you less stringent values you can meet if you decide to use any alternative paths towards compliance. This gives homeowners and home builders some freedom and flexibility and how they choose to achieve energy efficiency. 

As you look through the requirements for each climate zone, pay attention to the amendments and revisions that may have impacted these thresholds. Some substantial modifications include ceiling duct insulation above and below your ducts, as well as insulated siding.