Foundations & Slabs:
- Foundation: The base of a building that transfers its load to the ground and provides stability.
- Slab: A flat, horizontal concrete surface used as a floor or foundation.
- Slab on Grade: A concrete slab poured directly at ground level, often over a vapor barrier and gravel base.
- Monolithic Slab: A slab where the footing and floor are poured at the same time without joints.
- Wire Mesh/Rebar: Steel reinforcement placed in concrete to increase strength and control cracking.
- Thermal Mass: A material’s ability to absorb, store, and slowly release heat, helping regulate indoor temperature.
- Passive Solar Heating: Use of building orientation, windows, and materials to capture and store solar energy without mechanical systems.
- Crawl Space Foundation: A raised foundation leaving a shallow space under the building for access to plumbing and wiring.
- Vented Crawl Space: A crawl space with vents allowing outdoor air to circulate beneath the structure.
- Unvented Crawl Space: A sealed crawl space included in the conditioned volume of the home.
- Basement Foundation: A foundation that includes below-grade living or storage space.
Framing (Structural Skeleton):
- Framing: The structural skeleton of a building made of wood or metal members.
- Sill/Mud Sill: A treated horizontal piece of lumber that rests on the foundation and supports the floor frame.
- Joist: A horizontal structural member that supports floors or ceilings.
- Open Web Truss (OWT): An engineered joist with diagonal web members forming triangles for strength.
- Truss Joist (TJI): An engineered “I-beam” joist with OSB webs and wood flanges.
- Rim Joist: A joist that runs around the perimeter of the floor system, tying joists together.
- Band Joist: A joist parallel to the floor joists at the ends of the building; helps transfer loads.
- Sub-floor: Plywood or OSB sheathing installed over joists to support finished flooring.
- Plate (Top/Bottom Plate): Horizontal framing members at the top and bottom of walls that hold studs in place.
- Stud: A vertical framing member in walls.
- Jack Stud: A shorter stud supporting a header above an opening.
- King Stud: A full-height stud placed alongside a jack stud for reinforcement.
- Cripple Stud: A short stud located above or below an opening (e.g., under a window sill).
- Header: A horizontal structural member above a door or window opening.
- Beam: A horizontal load-bearing member spanning openings or carrying loads.
- Rafter: A sloped roof framing member extending from ridge to wall plate.
- Truss: A prefabricated triangular frame used to support roof or floor loads.
- Structural Insulated Panel (SIP): Prefabricated panel combining insulation and structural sheathing.
- Advanced Framing: Techniques designed to use less lumber, reduce thermal bridging, and increase insulation.
- Raised Heel Truss: A roof truss with extended heel height to allow more insulation at exterior walls.
- California Corner: A framing technique at corners that allows more insulation space.
- Ladder Blocking: A method of framing interior wall intersections that reduces unnecessary studs.
Windows & Doors:
- NFRC Label: A rating label from the National Fenestration Rating Council showing energy performance.
- U-Factor: A measure of heat loss; lower numbers mean better insulation.
- Solar Heat Gain Coefficient (SHGC): A measure of how well a window blocks heat from sunlight; ranges 0–1.
- Visible Transmittance (VT): The fraction of visible light passing through a window; ranges 0–1.
- Air Leakage (AL): The rate at which air passes through a window or door assembly.
- Flashing: Thin material (metal, plastic, or membrane) installed to direct water away from joints.
- Pan Flashing: A waterproofing detail at the base of a window or door opening.
HVAC (Heating, Ventilation, Air Conditioning):
- Furnace: A heating appliance that warms air and distributes it via ducts.
- Natural Draft Furnace: A furnace relying on buoyancy of hot exhaust gases to vent combustion byproducts.
- Direct Vent Furnace: A sealed combustion furnace that draws in outside air and vents exhaust directly outdoors.
- Heat Exchanger: A component that transfers heat between combustion gases and the indoor air supply.
- Evaporator Coil: A coil where refrigerant absorbs indoor heat during cooling.
- Compressor: The pump in an AC or heat pump that pressurizes refrigerant to transfer heat.
- Condenser Coil: An outdoor coil where refrigerant releases heat.
- Heat Pump: A system that can heat or cool by transferring heat between indoors and outdoors.
- Air Source Heat Pump (ASHP): A heat pump that exchanges heat with outside air.
- Ductless Mini-Split: A two-part system (indoor and outdoor units) that provides heating/cooling without ducts.
- Ducted Mini-Split: A heat pump using a small duct system for multi-room distribution.
- PTAC (Packaged Terminal Air Conditioner): A self-contained unit installed through a wall for heating/cooling.
- PTHP (Packaged Terminal Heat Pump): A PTAC unit that includes heat pump functionality.
- Ground Source Heat Pump (GSHP/Geothermal): A heat pump exchanging heat with the ground for efficient heating/cooling.
- Boiler: A heating system that heats water or steam for distribution via radiators or pipes.
- Radiator: A heat emitter that transfers hot water/steam heat into a room.
- Fan Coil Unit: A heating/cooling device using a coil and fan to distribute conditioned air.
- Central Air Conditioning: A system with outdoor compressor/condenser and indoor evaporator distributing cooled air via ducts.
- Window AC: A self-contained air conditioner mounted in a window opening.
Ventilation & Ducting:
- Mechanical Ventilation: Systems that bring in outdoor air and exhaust indoor air to maintain indoor air quality.
- Exhaust-Only System: Ventilation relying on fans to expel indoor air, with makeup air entering through leaks.
- Supply-Only System: Ventilation that pushes outdoor air into a home without active exhaust.
- Balanced System: A ventilation system that both supplies and exhausts air, often with energy recovery.
- HRV (Heat Recovery Ventilator): A system that transfers heat between incoming and outgoing air streams.
- ERV (Energy Recovery Ventilator): Similar to HRV but also transfers moisture between air streams.
- Ductwork: A system of tubes (metal, flex, or fiberglass) that distributes conditioned air throughout a building.
- Sheet Metal Ducting: Rigid ducts made of galvanized steel or aluminum.
- Flex Ducting: Flexible, insulated ducts that bend around obstacles.
- Fiberglass/Fiberboard Ducts: Ducts made from compressed fiberglass or fiberboard sheets.
- Dryer Ducts: Specialized ducts designed only for venting clothes dryers.
- Boot (Duct Boot): A fitting that connects ductwork to a grille/register.
- Jumper Duct: A short duct connecting rooms to allow airflow and balance pressure.
- Transfer Grille: An opening that allows air movement between spaces without ducting.
- Diffuser: A vent that spreads airflow evenly in a room.
- Grille: A vent cover without a damper, usually for return air.
- Register: A supply grille with an adjustable damper to control airflow.
Miscellaneous:
- Blower Door: diagnostic equipment used to pressurize a home and test the envelope for air leakage
- CAZ: Combustion Safety Exam - RFI candidates must take it, so must Rater Candidates. (If an RFI passes it and then goes on to become a rater, they don't have to take it again.
- Duct Blaster: diagnostic equipment used to pressurize ductwork and test for air leakage
- HERS: Home Energy Rating System
- HERS Modeler Practical Evaluation: test taken by Modeler Candidates
- Manometer: handheld gauge used to measure air pressure
- Mentored Rating or Mentored Model: done under the supervision of an experienced Rater by RFI or Modeler Candidates to learn to gather data in the field or create computer models.
- NEHERS: Northeast Home Energy Rating System Alliance - a non-profit based in MA that runs trainings for RFIs, Modelers and HERS Raters.
- Practical Simulation Exam: one of three tests taken by HERS Rater Candidates.
- Probationary Rating: practice rating done by HERS Rater Candidates (5 required)
- Rater Exam: one of three tests taken by HERS Rater Candidates.
- RESNET: Residential Energy Services Network (oversees the HERS Industry in the US)
- RFI: Rating Field Inspector