HERS HERS Thermal Envelope Insulation and Air Sealing

Question 1

In HERS energy modeling, what is the thermal performance metric used to describe the insulating value of a wall assembly including all components?

Accepted Answer

Assembly R-value (whole-wall R-value)

Answer

R-value

Answer

U-factor

Answer

C-value

Question 2

A HERS rater is inspecting a home with spray polyurethane foam (SPF) insulation in the roof deck. What ventilation configuration applies to this assembly?

Accepted Answer

Unvented conditioned attic — the HVAC system must be inside the thermal envelope

Answer

Vented attic with ridge and soffit vents

Answer

Ventilated crawl space below

Answer

Vented cathedral ceiling with 1-inch airspace

Question 3

What is the RESNET-recognized default infiltration rate used for the Reference Home in HERS Index calculations?

Accepted Answer

7 ACH50

Answer

3 ACH50

Answer

5 ACH50

Answer

0.35 ACHn

Question 4

Which area of a home typically accounts for the greatest air leakage in standard U.S. construction according to blower door diagnostic studies?

Accepted Answer

Top plates and ceiling penetrations

Answer

Window and door frames

Answer

Exterior wall sheathing seams

Answer

Foundation sill plate

Question 5

A HERS rater verifies continuous rigid foam insulation on the exterior of a wall assembly. What thermal performance benefit does this provide beyond cavity insulation alone?

Accepted Answer

Elimination of thermal bridging through framing members

Answer

Increased vapor permeance

Answer

Higher combustion safety margin

Answer

Reduced blower door test time

Question 6

Under IECC 2021 for climate zone 5, what is the minimum required attic insulation R-value for a new home?

Accepted Answer

R-49

Answer

R-38

Answer

R-60

Answer

R-30