I85PREP
⌘ K
ICC Res Energy study materials
ICC Res Energy study resources

ICC Res Energy practice questions

One question at a time. Build your ICC Res Energy understanding.

First 50 of 200 questions. Each one lists the choices, the correct answer, and an explanation. The checker at the top of this page saves progress in this browser when it is available.

Continue in the practice tool above to load more questions, 50 at a time.

Question 1Administration, Scope and Enforcement of the Residential Energy Code

Which of the following structures is within the scope of the residential provisions of the code?

  1. A five-story hotel of Group R-1 occupancy
  2. A two-story building occupied entirely by Group B business offices with a total floor area of 20,000 square feet (1858 m2)
  3. A three-story townhouse with an independent means of egress Correct answer.
  4. A single-story restaurant of Group A-2 occupancy

Explanation

The residential provisions govern detached one- and two-family dwellings, multiple single-family dwellings (townhouses), and Group R-2, R-3 and R-4 buildings that are not more than three stories above grade plane. Group A, B and R-1 occupancies fall outside that description.

Question 2Administration, Scope and Enforcement of the Residential Energy Code

For purposes of determining scope, how is a townhouse described?

  1. A dwelling unit above a store in a mixed-use building with a separate entrance
  2. A dwelling unit that shares one or more common walls with other dwelling units and that has its own separate entrance directly to the exterior or to a common corridor
  3. Two dwelling units attached side by side on one lot, each with open space on three sides
  4. A unit in a group of three or more attached units, each extending from foundation to roof, with open space on at least two sides Correct answer.

Explanation

A townhouse is a single-family dwelling unit constructed in a group of three or more attached units, each of which extends from foundation to roof and has open space on at least two sides. The definition is used to decide whether the residential provisions apply to the building.

Question 3Administration, Scope and Enforcement of the Residential Energy Code

Which requirements must a residential building satisfy no matter which compliance path the designer selects?

  1. Only the requirements of the compliance path that was selected
  2. Only the requirements of the standards that are referenced in the selected compliance path and in Chapter 4
  3. The mandatory provisions that apply to the building, in addition to the selected path Correct answer.
  4. Only the envelope requirements of Chapter 4

Explanation

The code is structured so that certain mandatory provisions apply to every project. The designer then chooses an additional path: prescriptive, simulated performance, or energy rating index.

Question 4Administration, Scope and Enforcement of the Residential Energy Code

Who is responsible for completing the permanent certificate required for a new dwelling?

  1. The energy rater who performed the analysis
  2. The code official after the final inspection
  3. The owner after taking occupancy of the dwelling
  4. The builder or registered design professional Correct answer.

Explanation

The code requires a permanent certificate completed by the builder or registered design professional and posted on a wall in the space where the furnace is located, a utility room, or another approved location. It lists the predominant insulation R-values and the installed equipment efficiencies.

Question 5Administration, Scope and Enforcement of the Residential Energy Code

How is a conditioned space defined for purposes of the code?

  1. An area, room or space that is heated or cooled by equipment or an appliance Correct answer.
  2. A space used for storage or circulation within the dwelling
  3. Any space inside the building thermal envelope, whether or not it is heated or cooled
  4. A space that is mechanically ventilated but not heated or cooled

Explanation

A conditioned space is one that is heated or cooled by equipment or an appliance. The term controls which spaces are counted and which envelope requirements apply.

Question 6Administration, Scope and Enforcement of the Residential Energy Code

A builder disagrees with the code official's interpretation of an envelope requirement. Where is the proper place to seek relief?

  1. The circuit court that has jurisdiction over the project
  2. The manufacturer of the product in question
  3. The board of appeals established for that jurisdiction Correct answer.
  4. The state energy office that adopts the code

Explanation

The code provides an appeal process, and appeals of the code official's decisions are heard by the board of appeals established for the jurisdiction. Court review comes only after the administrative remedy is exhausted.

Question 7Administration, Scope and Enforcement of the Residential Energy Code

When must the code official have the opportunity to inspect insulation and air sealing in the building thermal envelope?

  1. Before the work is concealed, while it remains accessible for inspection Correct answer.
  2. Only when the code official requests it in writing before the permit is issued
  3. Only when the project is using the performance compliance path
  4. At the final inspection, after all finishes are in place

Explanation

Required inspections occur at stages when the work is still exposed so that compliance can actually be verified. Once the envelope is concealed, the code official may require the work to be exposed again for inspection.

Question 8Administration, Scope and Enforcement of the Residential Energy Code

Which statement correctly describes how a standard referenced in the code applies to a project?

  1. The referenced standard applies in its entirety, whether or not the code says so
  2. Only the first edition of the referenced standard published after the code year applies
  3. Referenced standards are guidance, and compliance with them is optional
  4. The referenced standard applies only to the extent that the code references it Correct answer.

Explanation

A referenced standard becomes part of the code's requirements only to the prescribed extent of the reference. Where the code text and a referenced standard differ, the code text governs.

Question 9Administration, Scope and Enforcement of the Residential Energy Code

Two provisions of the code impose different requirements on the same building component. Which requirement applies?

  1. The requirement that appears first in the code
  2. The more restrictive of the two requirements Correct answer.
  3. The requirement that the code official finds easier to enforce
  4. The requirement selected by the registered design professional

Explanation

Where different sections of the code specify different requirements for the same case, the most restrictive requirement governs. This rule prevents a designer from selecting a less demanding provision when two apply.

Question 10Administration, Scope and Enforcement of the Residential Energy Code

A bedroom and bathroom addition is built onto an existing one-family dwelling. How do the existing-building provisions apply?

  1. The addition must comply as new construction, and the unaltered existing portion need not be upgraded Correct answer.
  2. The addition is exempt because the dwelling was built before the code was adopted
  3. Only the addition's foundation and roof must comply with the code
  4. The entire dwelling must be brought into compliance as new construction

Explanation

Additions must conform to the requirements for new construction as they relate to the addition. The code does not require the unaltered portion of the existing building to be brought up to current requirements as a condition of building the addition.

Question 11Administration, Scope and Enforcement of the Residential Energy Code

The furnace in an existing dwelling is replaced with a new unit of a different model. What does the code require?

  1. The dwelling must demonstrate compliance using the simulated performance path
  2. The replacement unit must comply with the code requirements for new equipment Correct answer.
  3. The entire duct distribution system must be replaced at the same time
  4. Nothing, because the furnace is a replacement rather than an alteration

Explanation

Work on an existing building system must comply with the code requirements applicable to that system as new work. Replacing the furnace therefore requires the new unit to meet the efficiency and other requirements for new equipment.

Question 12Administration, Scope and Enforcement of the Residential Energy Code

An existing building is converted from a warehouse to dwelling units, a change that increases the demand for energy in the space. What does the code require?

  1. Only the heating equipment must be replaced
  2. Nothing, because the building's envelope is existing
  3. The change of occupancy is prohibited unless the building is historic
  4. The space must comply with the requirements of the code applicable to new construction Correct answer.

Explanation

Where a change of occupancy or use would result in an increased demand for energy, the affected space must be brought into compliance with the code as it applies to new construction. The increased energy demand is what triggers the requirement.

Question 13Administration, Scope and Enforcement of the Residential Energy Code

When may construction of a new dwelling begin?

  1. After the owner has signed the compliance certificate for the dwelling
  2. After the foundation inspection, provided the documents are submitted later
  3. After the permit application is filed, so that review does not delay the schedule
  4. After the code official has approved the construction documents and issued the permit Correct answer.

Explanation

Work may not start until the code official has reviewed and approved the construction documents and the permit has been issued. Approval of the documents is the mechanism by which compliance is established before construction.

Question 14Administration, Scope and Enforcement of the Residential Energy Code

A designer proposes an insulation system that is not described anywhere in the code. On what basis may the code official approve it?

  1. Only if the building is also complying through the energy rating index path
  2. Only if the system has been used in another jurisdiction that enforces the same code
  3. Only if the registered design professional accepts full responsibility for the system in a signed letter to the owner
  4. Only if evidence shows the system is at least equivalent in performance and complies with the code's intent Correct answer.

Explanation

The code permits alternative materials, designs and methods of construction when the code official finds them satisfactory and equivalent in performance to the prescribed approach. The applicant must supply evidence, such as test data or calculations, to support that finding.

Question 15Administration, Scope and Enforcement of the Residential Energy Code

After the code official approves a set of construction documents, the contractor wants to make a field change that affects energy compliance. What is required?

  1. The revised documents must be submitted and approved before the change is made Correct answer.
  2. Nothing, provided the change does not increase the construction cost
  3. Nothing, provided the change is recorded on the as-built drawings
  4. The change may be made if the code official is notified after the final inspection

Explanation

Approved construction documents may not be altered without the approval of the code official. Changes affecting compliance must be resubmitted so that compliance can be reviewed before the work is done.

Question 16Administration, Scope and Enforcement of the Residential Energy Code

The code official finds work that is contrary to the code. What is the proper action?

  1. Revoke the building's certificate of occupancy and require the owner to reapply
  2. Issue a stop work order, and the work may not resume until compliance is confirmed Correct answer.
  3. Wait until the final inspection and note the violation on the inspection record
  4. Refer the matter to the design professional, who resolves it without the code official

Explanation

The code official has authority to issue a stop work order for work done contrary to the code. The work may not resume until the code official confirms that the noncompliance has been corrected.

Question 17Administration, Scope and Enforcement of the Residential Energy Code

What is the standard consequence of violating a provision of the code?

  1. Automatic suspension of the contractor's license for a minimum period of one year
  2. A mandatory requirement to demolish all noncomplying work
  3. No consequence once the certificate of occupancy has been issued
  4. A penalty prescribed by law, with each day of continuance a separate offense Correct answer.

Explanation

The code makes violations subject to penalties prescribed by law, and each day that a violation continues can be treated as a separate offense. The code official also has authority to pursue corrective action.

Question 18Administration, Scope and Enforcement of the Residential Energy Code

Water-damaged sheathing on an existing dwelling is repaired. How do the existing-building provisions apply to the repair?

  1. The repair triggers full compliance of the dwelling with the current code
  2. The repair is permitted without bringing the rest of the dwelling into compliance Correct answer.
  3. The repair is prohibited unless the dwelling was built under the current code
  4. The repair must use materials that exceed the code's minimum thermal performance

Explanation

Repairs are addressed in the existing-building chapter, which allows the repair without requiring the unaltered portions of the building to be upgraded. The repair itself must still be done so that it does not create an unsafe condition or reduce performance.

Question 19Administration, Scope and Enforcement of the Residential Energy Code

A two-story building has a restaurant on the first story and dwelling units on the second story. How is the energy code applied to this building?

  1. The residential provisions apply to the entire building because dwelling units occupy part of it, and no commercial requirements apply
  2. Either set of provisions may be applied to the entire building at the owner's option
  3. The commercial provisions apply to the entire building because the building is not a dwelling
  4. Dwelling units comply with the residential provisions and the restaurant with the commercial provisions Correct answer.

Explanation

Each portion of a building is evaluated against the provisions that apply to that portion. The dwelling units are within the residential scope, while the restaurant is a commercial occupancy regulated by the commercial provisions.

Question 20Administration, Scope and Enforcement of the Residential Energy Code

Under the simulated performance compliance path, what must the proposed design demonstrate?

  1. That its installed construction cost does not exceed that of the standard reference design
  2. That it achieves an energy rating index that is lower than the index of the standard reference design
  3. That its annual energy cost does not exceed that of the standard reference design Correct answer.
  4. That it uses the same equipment types as the standard reference design

Explanation

The simulated performance path compares the proposed design with a standard reference design of the same shape and size. The proposed design must have an annual energy cost that does not exceed the annual energy cost of the reference design.

Question 21Administration, Scope and Enforcement of the Residential Energy Code

A builder chooses to show compliance using the energy rating index path. Which statement is correct?

  1. The index must be calculated by the code official using the prescriptive tables
  2. The energy rating index report replaces the need to comply with the envelope requirements of the code
  3. The path may be used only for dwellings with a floor area under 3,000 square feet (279 m2)
  4. The index must be verified by an approved energy rater, and the mandatory provisions still apply Correct answer.

Explanation

The energy rating index path requires an index at or below the value referenced for the climate zone, verified by an approved energy rater, with the report provided as required. The mandatory provisions applicable to the building must still be satisfied.

Question 22Administration, Scope and Enforcement of the Residential Energy Code

Which activities on an existing building are addressed by the chapter on existing buildings?

  1. Additions, alterations, repairs and changes of occupancy Correct answer.
  2. Only work that adds conditioned floor area to the building
  3. Additions and alterations only, because repairs and changes of occupancy are unregulated
  4. Only work that the code official determines is substantial

Explanation

The existing-building chapter governs additions, alterations, repairs and changes of occupancy. Each activity is subject to its own requirements rather than to a rule requiring the whole building to be upgraded.

Question 23Administration, Scope and Enforcement of the Residential Energy Code

What must the permit holder do so that required inspections of energy-related work can be made?

  1. Arrange for the manufacturer to certify each installed product
  2. Keep a daily log of construction activity for the code official
  3. Notify the code official when each stage of work is ready for inspection Correct answer.
  4. Submit a final energy report before the first inspection

Explanation

The permit holder is responsible for notifying the code official when work reaches a stage that requires inspection. This keeps concealed work accessible so compliance can be verified.

Question 24Administration, Scope and Enforcement of the Residential Energy Code

A Group R-2 apartment building is designed to be four stories above grade plane. Which provisions govern the energy efficiency of the building?

  1. The commercial provisions of the code Correct answer.
  2. The residential provisions, because the building contains only dwelling units
  3. Neither, because the code's scope is limited to one- and two-family dwellings
  4. The residential provisions, applied only to the first three stories

Explanation

Group R-2 occupancies are within the residential scope only up to three stories above grade plane. A four-story Group R-2 building therefore falls outside that scope and is regulated by the commercial provisions.

Question 25Administration, Scope and Enforcement of the Residential Energy Code

Which statement best describes the construction documents submitted for a dwelling project regulated by the code?

  1. Information of sufficient clarity to show that the work will conform to the code Correct answer.
  2. A cost breakdown showing the budget for energy-related construction items
  3. A complete product catalog for every material to be installed in the dwelling
  4. A certificate of occupancy signed before the work begins

Explanation

Construction documents must be clear enough to show the location, nature and extent of the work and to demonstrate that it will conform to the code. They are the basis for the code official's review and for later inspections.

Question 26Administration, Scope and Enforcement of the Residential Energy Code

What is the stated purpose of the Residential Energy Code?

  1. To regulate the retail price of energy sold to residential customers.
  2. To establish minimum requirements for energy-efficient design and construction. Correct answer.
  3. To require on-site renewable energy generation in every new dwelling.
  4. To establish maximum allowable monthly utility bills for dwellings.

Explanation

The code sets minimum requirements for energy-efficient design and construction of residential buildings. It is not a utility-billing, renewable-generation mandate, or energy-pricing regulation.

Question 27Administration, Scope and Enforcement of the Residential Energy Code

Which buildings are regulated by the residential energy provisions?

  1. One- and two-family dwellings, townhouses, and low-rise R occupancies. Correct answer.
  2. Only hotels and motels classified in Group R-1, regardless of size or height.
  3. Only buildings whose annual energy use exceeds a threshold set by the code official.
  4. Every building of any occupancy group, including high-rise commercial buildings.

Explanation

The residential provisions cover detached one- and two-family dwellings, multiple single-family dwellings such as townhouses, and certain Group R-2, R-3 and R-4 buildings that are not more than three stories above grade plane. They do not apply to all occupancies or only to hotels.

Question 28Administration, Scope and Enforcement of the Residential Energy Code

Under the prescriptive compliance path, which statement is correct?

  1. Any requirement may be omitted if the total annual energy cost is reduced.
  2. Trade-offs among envelope components are allowed without any limitation or documentation.
  3. Mechanical equipment efficiency is never addressed by the prescriptive path.
  4. Components must meet prescriptive requirements, and mandatory provisions still apply. Correct answer.

Explanation

The prescriptive path requires the building components to satisfy the applicable component requirements, and the code's mandatory provisions apply regardless of the compliance path chosen. Unlimited trade-offs and wholesale omission of requirements are not permitted.

Question 29Administration, Scope and Enforcement of the Residential Energy Code

If the code official has reason to question whether a material or assembly complies with the code, what may the code official require?

  1. The owner to remove and replace the material with a listed product.
  2. Tests to be performed to demonstrate that the material complies. Correct answer.
  3. The contractor to submit a letter describing the intent to comply.
  4. The designer to revise the plans to use the performance path.

Explanation

The code official is authorized to require tests to verify compliance of materials, assemblies, or methods of construction. Removal, a letter of intent, or a change of compliance path is not the standard response to a compliance question.

Question 30Administration, Scope and Enforcement of the Residential Energy Code

A code official finds work being performed contrary to the approved construction documents. What action is authorized?

  1. File criminal charges without providing notice to the permit holder.
  2. Immediately revoke the contractor's license without a hearing.
  3. Approve the work as an alternative method of construction.
  4. Issue a stop-work order for the affected work. Correct answer.

Explanation

The code official may issue a stop-work order when work is contrary to the approved documents or the code. Licensing revocation and criminal prosecution are not the code official's immediate administrative remedy, and noncompliant work cannot simply be approved.

Question 31Administration, Scope and Enforcement of the Residential Energy Code

When may a code official grant a modification of a code requirement?

  1. The building is an existing dwelling and the owner files a written waiver.
  2. Strict application is impractical and the intent is met without reduced safety. Correct answer.
  3. The requirement conflicts with the manufacturer's published installation instructions.
  4. The applicant demonstrates that compliance would cost more than the proposed alternative.

Explanation

A modification may be granted only in specific cases where strict application is impractical and the modification preserves the code's intent and safety. Cost alone, an owner's waiver, or a manufacturer's instructions do not authorize a modification.

Question 32Administration, Scope and Enforcement of the Residential Energy Code

What is the effect of the code official's approval of construction documents?

  1. It does not relieve the permit holder of responsibility for code compliance. Correct answer.
  2. It guarantees that the design complies with every code requirement.
  3. It transfers responsibility for compliance to the code official.
  4. It authorizes occupancy before the required inspections are complete.

Explanation

Approval of construction documents allows work to proceed but does not relieve the permit holder of the duty to comply with the code. The code official does not assume the designer's or builder's responsibility, and approval does not authorize early occupancy.

Question 33Administration, Scope and Enforcement of the Residential Energy Code

How does the residential energy code apply to a manufactured home built to the federal HUD code?

  1. The residential energy code applies if the home is installed on a permanent foundation.
  2. The state or local energy code applies in full to the manufactured home.
  3. The residential energy code applies only to the home's foundation and utility connections.
  4. Federal standards preempt state and local requirements for the home. Correct answer.

Explanation

Manufactured homes constructed to the federal HUD code are governed by that federal standard, which preempts state and local construction requirements for the home. Local rules may still address installation matters, but the residential energy code does not apply in full to the home itself.

Question 34Administration, Scope and Enforcement of the Residential Energy Code

After a dwelling is occupied, who is responsible for maintaining its energy-related systems in compliance with the code?

  1. The owner or the owner's designated agent. Correct answer.
  2. The original builder for the entire life of the building.
  3. The utility provider serving the building.
  4. The code official through routine periodic inspections.

Explanation

Ongoing maintenance of a dwelling's energy-related systems is the responsibility of the owner or the owner's agent. Code officials enforce the code but do not perform routine maintenance inspections, and neither the builder nor the utility provider bears lifelong maintenance responsibility.

Question 35Building Envelope (Insulation, Fenestration, Air Leakage)

In Climate Zones 1 and 2, the maximum tested air leakage rate for a dwelling under the IECC residential provisions is:

  1. 5.0 air changes per hour at 50 Pa Correct answer.
  2. 7.0 air changes per hour at 50 Pa
  3. 2.5 air changes per hour at 50 Pa
  4. 3.0 air changes per hour at 50 Pa

Explanation

The IECC sets a maximum whole-house air leakage rate based on climate zone, with warmer zones allowing a higher limit. Climate Zones 1 and 2 are permitted up to 5.0 ACH50. Colder zones must meet progressively tighter limits.

Question 36Building Envelope (Insulation, Fenestration, Air Leakage)

What is the primary function of a continuous air barrier in the building thermal envelope?

  1. Provide structural bracing for the wall sheathing
  2. Increase the R-value of the installed cavity insulation
  3. Raise the solar heat gain of the windows
  4. Limit uncontrolled air leakage through the envelope Correct answer.

Explanation

A continuous air barrier creates a sealed boundary that resists uncontrolled air movement between conditioned and unconditioned spaces. It is separate from insulation, which resists conductive heat flow. Sealing joints and penetrations is essential to its performance.

Question 37Building Envelope (Insulation, Fenestration, Air Leakage)

A vapor retarder is installed in the thermal envelope primarily to:

  1. Seal electrical penetrations against air flow
  2. Reduce moisture diffusion into assemblies Correct answer.
  3. Stop liquid water from rain from entering the wall
  4. Increase the thermal resistance of insulation

Explanation

A vapor retarder limits the diffusion of water vapor into building assemblies, helping prevent condensation within the envelope. It is not a waterproofing membrane and is not an air barrier. Insulation R-value is a separate property.

Question 38Building Envelope (Insulation, Fenestration, Air Leakage)

Faced batt insulation in a framed wall must be installed:

  1. Compressed tightly into each cavity to save space
  2. In substantial contact with the insulated surface Correct answer.
  3. With a continuous air gap on the warm side
  4. Only on the exterior side of the sheathing

Explanation

The IECC requires insulation to be installed in substantial contact with the surface being insulated. Gaps and compression reduce the effective R-value. Batt insulation should fill the cavity without being crushed.

Question 39Building Envelope (Insulation, Fenestration, Air Leakage)

For a window, a lower U-factor indicates:

  1. Greater solar heat gain
  2. Stronger frame construction
  3. Higher visible light transmission
  4. Better resistance to heat flow Correct answer.

Explanation

U-factor measures the rate of heat flow through an assembly, so a lower number means better thermal resistance. It is the inverse of R-value. Solar heat gain and visible light are separate performance measures.

Question 40Building Envelope (Insulation, Fenestration, Air Leakage)

Solar heat gain coefficient (SHGC) measures:

  1. The solar radiation admitted through the fenestration Correct answer.
  2. The visible light transmitted through the glazing material
  3. The winter nighttime U-factor of the window frame assembly
  4. The air leakage rate measured around the window frame

Explanation

SHGC is the fraction of incident solar radiation that enters through the fenestration as heat. Lower values reduce solar heat gain. It is distinct from visible transmittance and from U-factor.

Question 41Building Envelope (Insulation, Fenestration, Air Leakage)

Which assembly is classified as fenestration under the IECC residential provisions?

  1. A rim joist
  2. A slab edge
  3. An attic knee wall
  4. A skylight Correct answer.

Explanation

Fenestration includes glazed openings in the building envelope such as windows, doors, and skylights. Opaque assemblies like knee walls, rim joists, and slab edges are not fenestration. They are insulated as part of the opaque envelope.

Question 42Building Envelope (Insulation, Fenestration, Air Leakage)

An attic access hatch located in an insulated ceiling must be:

  1. Insulated and weatherstripped like the ceiling Correct answer.
  2. Left uninsulated so the attic can ventilate
  3. Sealed permanently with drywall and no access
  4. Equipped only with a self-closing latch

Explanation

Access openings in the thermal envelope must be insulated and weatherstripped to approximately the same level as the surrounding assembly. This limits both conduction and air leakage at a common weak point. A latch alone does not satisfy the requirement.

Question 43Building Envelope (Insulation, Fenestration, Air Leakage)

Recessed luminaires installed in an insulated ceiling must be:

  1. Open to the attic to allow heat to dissipate
  2. Insulation-contact rated and sealed against air leakage Correct answer.
  3. Installed with a two-inch gap around the housing
  4. Left unsealed so condensation can drain away

Explanation

Recessed fixtures in the thermal envelope must be rated for contact with insulation and sealed to prevent air leakage into the attic. Open or unsealed housings create significant envelope leakage. Gaps around the housing undermine the air barrier.

Question 44Building Envelope (Insulation, Fenestration, Air Leakage)

Why does the rim joist area of a wood-frame floor above a basement require special attention?

  1. It must remain open for foundation drainage
  2. It has no structural sheathing behind it
  3. It is a common air leakage and thermal bridge location Correct answer.
  4. It carries the greatest live load in the floor

Explanation

The rim joist is a frequent location for air leakage and thermal bridging because framing members and joints meet there. The IECC requires it to be sealed and insulated. Leaving it unaddressed can significantly degrade envelope performance.

Question 45Building Envelope (Insulation, Fenestration, Air Leakage)

In an unvented crawlspace, the IECC requires insulation to be installed:

  1. On the exterior or interior of the foundation wall Correct answer.
  2. On top of the ground vapor retarder
  3. Between the floor joists above the crawlspace
  4. On the crawlspace access door only

Explanation

An unvented crawlspace is treated as part of the conditioned envelope, so the foundation wall is insulated on its exterior or interior. Insulating only the floor above would leave the crawlspace outside the envelope. The ground vapor retarder is a moisture control measure, not insulation.

Question 46Building Envelope (Insulation, Fenestration, Air Leakage)

Slab-on-grade edge insulation must extend:

  1. Only across the top surface of the slab
  2. Horizontally beneath the entire slab
  3. From the slab top downward to the required depth Correct answer.
  4. From the footing upward a distance of one inch

Explanation

The IECC specifies slab-edge insulation that extends downward from the top of the slab to the depth required by the climate-zone table. This reduces heat loss at the slab perimeter. Insulation only under the slab or only at the top surface does not satisfy the edge requirement.

Question 47Building Envelope (Insulation, Fenestration, Air Leakage)

Continuous insulation on exterior walls is used primarily to:

  1. Replace all cavity insulation in the wall
  2. Reduce thermal bridging through framing members Correct answer.
  3. Eliminate the need for an air barrier
  4. Increase solar gain through the wall assembly

Explanation

Continuous insulation forms an uninterrupted layer outside the framing, reducing thermal bridging through studs and plates. It is generally used in combination with cavity insulation rather than replacing it. An air barrier is still required separately.

Question 48Building Envelope (Insulation, Fenestration, Air Leakage)

Air sealing of a wood-frame wall must include sealing:

  1. Joints and penetrations at top and sole plates Correct answer.
  2. Only the exterior sheathing seams
  3. Only the areas around windows and doors
  4. The interior drywall joints only

Explanation

The air barrier must be continuous, and common leakage paths include the top plate and sole plate joints and penetrations. These must be sealed along with other envelope joints. Sealing only sheathing seams or only around windows leaves major paths open.

Question 49Building Envelope (Insulation, Fenestration, Air Leakage)

A wood-burning fireplace installed in the thermal envelope must have:

  1. A masonry chimney without a cap
  2. Gasketed doors and outdoor combustion air Correct answer.
  3. An open damper for continuous ventilation
  4. A glass front that is left slightly ajar

Explanation

The IECC requires fireplaces to limit air leakage, typically through gasketed doors and a sealed firebox or an outdoor combustion air supply. An open damper or ajar door permits continuous leakage. A chimney cap does not address envelope air sealing.

Question 50Building Envelope (Insulation, Fenestration, Air Leakage)

The wall between a dwelling and an attached garage is required to be:

  1. Air sealed and insulated as part of the envelope Correct answer.
  2. Finished with exterior siding on the house side
  3. Uninsulated to allow heat loss from the garage
  4. Vented to the outdoors through the garage wall

Explanation

Because the garage is outside the conditioned envelope, the common wall must be insulated and air sealed. This also helps prevent garage air from entering the dwelling. Exterior siding or venting does not satisfy the envelope requirement.