Home Services Glossary
Plain-English definitions for terms contractors use. Know what you're agreeing to before you sign.
HVAC
SEER / SEER2Seasonal Energy Efficiency Ratio — a measure of an air conditioner's cooling eff…HSPFHeating Seasonal Performance Factor — the heating efficiency rating for heat pum…Refrigerant (R-22, R-410A, R-454B)The fluid that circulates through an AC system to move heat. R-22 (Freon) was ph…Heat PumpA heating and cooling system that moves heat rather than generating it. In summe…Static PressureResistance to airflow in your duct system, measured in inches of water column (I…Heat Load Calculation (Manual J)The ACCA Manual J is the industry-standard method for calculating how much heati…Short CyclingWhen an AC system turns on and off repeatedly in short intervals (less than 10 m…Mini-Split / Ductless SystemA heating/cooling system with a small outdoor compressor connected to one or mor…Capacitor (Run / Start)An electrical component that stores and releases energy to start and run the AC …ContactorAn electrical relay that controls power flow to the AC compressor and condenser …BTU/h (British Thermal Units per Hour)The standard unit for measuring heating and cooling capacity. 12,000 BTU/h = 1 t…Whole-House FanA large fan installed in the ceiling between the living space and attic that rap…Evaporator CoilThe indoor component of a central AC system where refrigerant absorbs heat from …Condenser CoilThe outdoor component of a central AC system that releases heat extracted from y…
Plumbing
Water HardnessConcentration of dissolved calcium and magnesium in your water, measured in grai…Tankless Water Heater (On-Demand)A water heater that heats water only when you need it, rather than maintaining a…Slab LeakA water or sewer pipe leak beneath the concrete foundation (slab) of a home. Com…Trenchless Sewer RepairSewer line repair methods that don't require excavating your entire yard. Two ma…Hydro-JettingA drain cleaning method that uses high-pressure water (1,500–4,000 PSI) to scour…Pressure Reducing Valve (PRV)A plumbing device that reduces municipal water pressure to a safe level for your…Anode RodA sacrificial magnesium or aluminum rod inside your water heater tank that corro…Frost-Free Hose BibAn outdoor faucet designed to prevent freezing — the shut-off valve is located 4…Galvanic CorrosionElectrochemical deterioration that occurs when two dissimilar metals are in cont…Thermal Expansion TankA small tank (typically 2–4 gallons) connected to a water heater to absorb press…Temperature & Pressure Relief Valve (T&P Valve)A safety device on water heaters that opens automatically if temperature or pres…Polybutylene PipeGrey plastic pipe used in homes built 1978–1995 that is prone to failure and was…
Roofing
Architectural Shingles (Dimensional / Laminate)The most common residential roofing material today — multi-layer asphalt shingle…Roofing Square100 square feet of roof area — the standard unit for roofing bids. A typical 3-b…FlashingThin metal strips (typically galvanized steel, aluminum, or copper) that seal jo…Roof Decking (Sheathing)The plywood or OSB panel layer that forms the structural base of your roof, atta…Ridge VentA ventilation component installed along the peak (ridge) of the roof that allows…Ice & Water ShieldA self-adhering waterproofing membrane applied to the roof deck in vulnerable ar…Class 4 Impact Resistant ShinglesThe highest impact resistance rating for roofing shingles, tested by dropping a …Insurance Supplement (Roofing)An additional claim submitted to your insurance company after the initial settle…Storm Chaser (Contractor)Out-of-town contractors who descend on areas after storms to solicit roofing and…
Solar
Kilowatt-Peak (kWp)The rated power output of a solar panel under standard test conditions (STC: 1,0…Net MeteringA billing arrangement where excess solar electricity sent to the grid earns cred…Solar InverterConverts DC electricity from solar panels to AC electricity used in your home. T…Battery Storage (Solar)Stores excess solar production for use at night or during grid outages. Common o…Grid InterconnectionThe utility approval process required before a solar system can connect to the g…Investment Tax Credit (ITC) — SolarFederal tax credit equal to 30% of the total cost of a solar system (panels, inv…ERCOT (Electric Reliability Council of Texas)The independent grid operator managing about 90% of Texas's electric load. ERCOT…
General
Permit (Building / Trade)Government authorization required before performing certain home improvement wor…Insurance DeductibleThe amount you pay out-of-pocket before insurance covers a claim. Standard homeo…Home Energy AuditA systematic assessment of where a home loses energy and how to cost-effectively…Electrical Load CalculationAssessment of your home's total electrical demand to ensure panel and service ca…HERS RatingHome Energy Rating System score — measures a home's energy efficiency on a scale…Air SealingSealing gaps, cracks, and penetrations in the building envelope to prevent condi…Homestead Exemption (Texas)A Texas tax benefit that reduces the appraised value of your primary residence f…10% Appraisal Cap (Texas)Texas law limits how much your homestead's appraised value can increase each yea…Electrical Grounding & BondingSafety systems that provide a low-resistance path for fault current to flow safe…