Updated July 2026 · Reviewed by RemodelyourHome.com editorial team
50+ terms across windows, roofing, flooring, siding, and general construction. If a contractor uses a term you do not recognize, this is where to look first.
U-factor: Measures how much heat transfers through a window. Lower is better.
SHGC (Solar Heat Gain Coefficient): How much solar energy enters through the glass. Lower blocks heat (good for hot climates); higher allows passive solar gain (good for cold climates).
Low-E glass: Glass with a microscopically thin metallic coating that reflects infrared heat. Standard on Energy Star windows. Improves both U-factor and SHGC control without reducing visible light.
Fibrex: Composite window frame material made from 50% reclaimed wood fiber and 50% thermoplastic polymer. Exclusive to Renewal by Andersen. 2× stronger than vinyl, 700× better thermal resistance than aluminum.
Casement window: Hinged on the side, opens outward with a crank. Excellent air seal when closed; good ventilation when open. Best for areas where you need maximum fresh air.
Double-hung window: Both upper and lower sashes slide vertically. Most common window type in North America. Both sashes tilt in for cleaning on modern double-hungs.
Argon fill: Inert gas pumped between double- or triple-pane glass to reduce heat transfer. More effective than air; less expensive than krypton fill. Standard on most Energy Star windows.
Energy Star: EPA certification for energy-efficient products. Windows must meet U-factor and SHGC requirements specific to four climate zones.
Architectural shingles: Also called dimensional or laminated shingles. Made of two layers of asphalt bonded together, creating a textured dimensional appearance. Heavier and longer-lasting than 3-tab shingles; most common roofing material in North America.
Decking / sheathing: The structural plywood or OSB panels that cover the roof framing and provide the surface to which shingles are nailed. Damaged decking must be replaced before new shingles are installed.
Flashing: Metal (usually aluminum or galvanized steel) installed at roof penetrations and transitions to prevent water infiltration. Chimney flashing, valley flashing, and step flashing are the most common types.
Ice and water shield: Self-adhering waterproof membrane installed at the eaves, valleys, and penetrations before shingles. Required by code in most cold-climate jurisdictions. Prevents water backup from ice dams.
Drip edge: Metal flashing installed along the eave and rake edges of a roof to direct water away from the fascia. Required by most building codes.
Ridge cap: Specially formed shingles installed at the roof peak. Often the first component to show wear. Missing or lifted ridge caps are a common source of leaks.
Square: Unit of roofing measurement equal to 100 square feet of roof surface. A 2,000 sqft ranch home might have 22–28 squares depending on roof complexity and pitch.
UL 2218 Class 4: The highest impact resistance rating for roofing materials. Shingles withstand a 2-inch steel ball dropped from 20 feet without cracking. Sometimes a condition of a hail-belt insurance discount — check with your own insurer rather than assuming.
LVP (Luxury Vinyl Plank): 100% waterproof flooring made from PVC (plastic) layers. Photographically printed wood grain appearance. Wear layer (measured in mils) is the key quality indicator — 12 mil for standard residential, 20 mil for heavy use.
Wear layer: The transparent top coating on LVP that protects against scratches and stains. Measured in mils (thousandths of an inch). 12 mil standard residential; 20 mil recommended for pets or heavy traffic.
Engineered hardwood: Real wood veneer (2–6mm) bonded to a plywood core. More dimensionally stable than solid hardwood — handles humidity changes better. Can go over radiant heat. Can typically be refinished 1–3 times.
PEI rating: Porcelain Enamel Institute rating for tile durability (PEI 0–5). PEI 4+ is required for shower floors and high-traffic floor areas. Lower ratings are for wall tile only.
Floating floor: Installation method where planks click or glue together but are not attached to the subfloor. LVP, laminate, and engineered hardwood are commonly installed as floating floors. Allows for expansion and contraction and is typically DIY-friendly.
Fiber cement: Composite material made from Portland cement, sand, and cellulose fiber. Non-combustible, does not rot, and does not attract insects. James Hardie is the dominant brand. Requires painting every 15–25 years.
LP SmartSide: Engineered wood siding product made from wood strands bonded with resin and treated with zinc borate for rot and insect resistance. More impact-resistant than fiber cement; requires painting every 8–12 years.
K-style gutter: The most common residential gutter profile, with a flat back and decorative crown-molding front. More efficient than half-round per inch of width. Available in 5-inch (standard) and 6-inch (high-capacity) widths.
Seamless gutter: Gutters formed on-site from a single continuous coil of aluminum, with no seams except at corners and downspouts. Dramatically reduces leak points compared to sectional gutters.
Change order: A written amendment to the original contract that modifies the scope, cost, or timeline. Any change to the agreed work should be documented in a signed change order before work begins.
Certificate of Insurance (COI): Document from an insurer confirming a contractor's coverage. You should be named as an additional insured on their general liability policy before any work begins on your property.
Lien waiver: Document signed by a contractor, subcontractor, or supplier releasing their right to file a mechanic's lien against your property for work performed. Request lien waivers at each payment milestone.
ACV (Actual Cash Value): Insurance valuation method that pays the depreciated value of damaged property — not what it costs to replace it. Compare to RCV.
RCV (Replacement Cost Value): Insurance valuation method that pays what it costs to replace damaged property at today's prices, with no depreciation deduction. RCV policies cost more in premium but provide better coverage.
R-value: Measure of insulation's resistance to heat flow. Higher R-value = better insulation. Recommended attic insulation is R-38 to R-60 depending on climate zone.
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