Energy Efficiency

A Permanent Energy Certificate Must Be Posted in the Dwelling

What is the energy certificate sticker by the furnace or electrical panel, and is it required?

R1101.14

Air Sealing Must Create a Continuous Thermal Envelope

What does the inspector look for on the energy code air sealing inspection?

R1102.5.1.1

Basement Wall Insulation Is Required by Climate Zone When the Basement Is in the Thermal Envelope

Do basement walls need insulation under the 2021 IRC energy code?

R1102.2.9

Component Performance Allows Some Envelope Tradeoffs but Not Unlimited Substitutions

Can I use better windows to make up for lower wall or attic insulation, or trade insulation values in the energy code?

R1102.1.5

Continuous Insulation Is Separate From Cavity Insulation in the Energy Code

What does 20 plus 5 ci, 13 plus 10 ci, or continuous insulation mean in the 2021 IECC?

R1102.1.4

Crawl Space Energy Compliance Depends on Vented or Unvented Design

Do I insulate the crawl space walls or the floor above the crawl space under the 2021 energy code?

R1102.2.11

Duct Systems Must Be Sealed and Tested for Leakage

Do my HVAC ducts need a duct leakage test for the 2021 energy code?

R1103.3.7

Ducts Outside Conditioned Space Need Insulation and Leakage Control

What R-value insulation is required for HVAC ducts in an attic, crawl space, garage, or outside conditioned space?

R1103.3.3

Insulation R-Values Depend on the IECC Climate Zone and Assembly Type

What R-value insulation do I need for walls, ceilings, floors, basement walls, slabs, and crawl spaces?

R1102.1.3

IRC 2021 Requires Blower Door Testing for Building Air Leakage

Is a blower door test required, and what ACH number does a new house have to pass?

R1102.5.1.3

IRC Chapter 11 Allows Prescriptive, Performance, ERI, and Tropical Compliance Paths

Do I have to follow the prescriptive insulation table, or can I use REScheck, performance, or a HERS rating?

R1101.13

Slab Edge Insulation Requirements Increase in Colder Climate Zones

When is slab edge insulation required, and how deep does it have to go?

R1102.2.10

Tight New Homes Need Whole-Dwelling Mechanical Ventilation

If my house passes the blower door test, do I also need a fresh air system, ERV, HRV, or whole-house ventilation?

R1103.6

Window U-Factor and SHGC Limits Are Set by Climate Zone

What U-factor and SHGC do my windows and glass doors need for the 2021 energy code?

R1102.1.2