AIA Contract
A standardized construction contract published by the American Institute of Architects, widely used for residential and commercial projects. AIA forms (A101, A102, etc.) define payment schedules, scope, and dispute procedures.
Reference
Plain-English definitions for the words you’ll see on contractor bids, permit applications, and inspection reports. 100 terms across 18 categories.
A standardized construction contract published by the American Institute of Architects, widely used for residential and commercial projects. AIA forms (A101, A102, etc.) define payment schedules, scope, and dispute procedures.
A budget set aside in a contract for items the homeowner has not yet selected (e.g. tile, fixtures, appliances). If the homeowner picks something more expensive than the allowance, they pay the difference; less expensive, they get a credit.
A written amendment to the original contract that changes scope, schedule, or price. Every change to the agreed-upon work should be documented as a change order with a price impact and a homeowner signature before the work happens.
A reserve in the project budget — typically 10–20% — set aside for unforeseen conditions discovered during construction. Older homes and gut remodels usually need higher contingencies than new construction.
A pricing structure where the homeowner pays for actual labor and material costs plus a contractor markup (often 15–25%) instead of a fixed price. Common on remodels with significant unknowns; requires open-book accounting.
The agreed sequence of payments tied to construction milestones (e.g. 10% at signing, 25% at framing complete, 25% at drywall, etc.). Lenders enforce draws on construction loans; cash projects often follow a similar structure.
A contract where the contractor agrees to complete the defined scope for one total price, absorbing material and labor cost risk. Best when scope is clearly defined; change orders adjust the fixed price.
A document signed by a contractor or subcontractor confirming they have been paid for work to date and waive their right to file a mechanic’s lien against the property. Always collect lien waivers with each progress payment.
A legal claim filed against a property by an unpaid contractor, sub, or supplier. Liens can block sale or refinancing until resolved. Lien waivers and timely payment are the standard protections.
The final list of small items to fix or finish before a project is considered complete (touch-up paint, missing trim, sticky doors). The punch list is typically created during a walkthrough and tied to the final payment.
A percentage of each progress payment (often 5–10%) withheld by the homeowner until the project is fully complete. Retainage protects against incomplete work and is released after the punch list is closed.
The detailed description of exactly what the contractor will and will not do, including materials, finishes, and exclusions. A clear scope of work is the foundation of comparable bids and a clean change-order process.
A pricing structure where the homeowner pays the contractor for actual hours worked (at agreed rates) plus material costs. Useful for repairs and small jobs where scope is uncertain; carries cost risk for the homeowner.
The local government body that enforces building codes and issues permits — usually the city or county building department. The AHJ has final say on code interpretation for your project.
Official authorization from the AHJ to begin a construction or alteration project. Permits trigger required inspections; unpermitted work can complicate sale, refinancing, and insurance claims.
A document issued by the AHJ certifying that a structure complies with applicable codes and is safe to occupy. Required for new construction and major additions before move-in.
Additional height above the FEMA base flood elevation (BFE) required by some local codes — typically 1–3 feet. Coastal jurisdictions like Virginia Beach and Norfolk often enforce freeboard on rebuilds and additions in flood zones.
The model building code adopted (often with amendments) by most U.S. jurisdictions for commercial and multi-family construction. Updated on a 3-year cycle.
A site visit by the AHJ to verify code compliance at specific construction milestones (footing, framing, electrical rough-in, plumbing rough-in, insulation, final). Failed inspections require rework and re-inspection.
The residential counterpart to the IBC, covering one- and two-family dwellings up to three stories. Most U.S. residential permits reference an IRC version (e.g. IRC 2018, IRC 2021).
The U.S. standard for electrical wiring and equipment (NFPA 70). Updated every 3 years; jurisdictions adopt specific editions. AFCI, GFCI, and tamper-resistant outlet rules are NEC-driven.
The minimum distance a structure must sit from a property line, street, or easement. Setbacks are set by zoning and constrain additions, decks, fences, and ADUs.
Permission from the local zoning board to deviate from a code requirement (e.g. building inside a setback). Variances usually require a hearing and a demonstrated hardship; expect 30–90 days.
A contractor has purchased a surety bond that guarantees completion of work and payment of subs/suppliers. Required by some jurisdictions and recommended for large projects; bond claims can compensate homeowners for incomplete or defective work.
Virginia’s contractor license tiers based on project size: Class A (no limit), Class B (up to $120K per project / $750K per year), Class C (up to $10K per project / $150K per year). Match the license class to your project value.
A document from the contractor’s insurance carrier showing current general liability and workers’ compensation coverage. Always request a current COI naming you as additional insured before work begins.
Insurance that covers damage a contractor causes to your property or third parties during construction. Reasonable minimum: $1M per occurrence / $2M aggregate; verify on the COI.
Insurance that covers a contractor’s employees if injured on your property. If a contractor lacks workers’ comp, an injured worker can pursue the homeowner’s policy. Verify on the COI before work begins.
The contractor responsible for managing the entire project: scheduling subs, ordering materials, pulling permits, coordinating inspections, and overseeing quality. Markups (general conditions + overhead + profit) typically run 15–25% of total project cost.
Shorthand for the three core building-systems trades. MEP rough-in (pipes, wires, ducts inside the walls) typically happens after framing and before drywall.
A specialist hired by the GC to perform a specific trade (electrical, HVAC, plumbing, roofing, drywall, etc.). Subs work for the GC, not the homeowner directly; payment flows through the GC.
The widened base of a foundation that distributes structural load into the soil. Footing depth must extend below the local frost line (varies by region; ~30 inches in Virginia).
A horizontal framing member spanning the top of a window, door, or other opening to transfer load around the gap. Header sizing depends on span and load above.
Horizontal framing members (typically 2x8 to 2x12 lumber, or engineered I-joists / TJIs) that support the floor or ceiling above. Joist sizing and spacing are dictated by span tables in the IRC.
A wall that supports structural weight from above (roof, ceiling, or upper floor). Removing a load-bearing wall requires a structural beam (LVL, steel, or glulam) and usually an engineer’s sign-off.
Sloped framing members that form the roof structure, running from the ridge to the exterior wall. In modern construction, prefab roof trusses often replace stick-framed rafters.
Structural panels (OSB or plywood) attached to the exterior of wall and roof framing to provide racking strength and a substrate for siding/roofing. Typically 7/16" or 1/2" thick.
A prefabricated, engineered framing member made of triangulated lumber and metal connectors. Roof trusses replace site-built rafters on most modern construction; floor trusses replace I-joists in some applications.
The efficiency rating for gas furnaces, expressed as a percentage. New furnaces typically range from 80% (standard) to 98% (high-efficiency condensing). Higher AFUE costs more upfront but cuts fuel bills.
A unit of heat used to size HVAC equipment. A typical residential AC system runs 18,000–60,000 BTU/h; sizing depends on square footage, insulation, climate, and window area (Manual J calculation).
Gypsum panels, typically 1/2" or 5/8" thick, used for interior walls and ceilings. Moisture-resistant ("green board" or "purple board") goes in bathrooms; fire-rated 5/8" Type X is required at garages and some ceilings.
The filtration efficiency rating for HVAC air filters, scale 1–20. Most residential systems use MERV 8–13. MERV >13 can restrict airflow on systems not designed for it; consult the equipment manual before upgrading.
An engineered wood panel made of compressed wood strands and resin, used as structural sheathing for walls, roofs, and floors. Cheaper than plywood and structurally equivalent for most applications.
A measure of how well insulation resists heat flow — higher R-value = better insulation. Typical recommendations: R-13 to R-21 in walls, R-30 to R-49 in attics. IECC adoption varies by jurisdiction.
The cooling efficiency rating for AC and heat-pump systems. As of January 2023, new units sold in the South (incl. Virginia) must meet SEER2 ≥ 14.3 (replacing the old SEER 14 minimum).
A material (often polyethylene sheeting or kraft-faced insulation) that resists moisture migration through walls or floors. Placement depends on climate zone — installed wrong, vapor barriers cause mold instead of preventing it.
A secondary, self-contained dwelling on the same lot as a primary home — detached (backyard cottage), attached (garage conversion), or interior (in-law suite). ADU rules vary widely by jurisdiction; many cities have liberalized rules in the past 5 years.
A renovation that strips a space (or whole home) down to the studs and rebuilds. Highest cost-per-square-foot category but allows full systems upgrades and floor-plan changes.
Upgrades that improve a building’s resistance to high winds and storm surge: impact-rated windows, hurricane straps, reinforced garage doors, generator hookups. Especially relevant in coastal Virginia and the Hampton Roads region.
A home that produces as much energy as it consumes annually, typically through deep-energy retrofits (insulation, air-sealing, high-efficiency HVAC) plus on-site solar generation. Costs 10–25% more upfront; payback varies by climate and utility rates.
A contractor’s formal price proposal for a defined scope of work. Bids should itemize labor, materials, subs, general conditions, overhead, profit, and any allowances or exclusions.
A bid issued before a contractor has performed an in-person site walkthrough, based on a structured project brief and supporting documentation. Contingent quotes let homeowners compare multiple bids quickly; finalists confirm the price after a walkthrough.
A non-binding ballpark price range for a project, typically given before detailed scope is defined. Distinct from a bid — an estimate is not a contract and the final price will differ.
A formal document a homeowner (or their architect) sends to multiple contractors describing the project and asking for a structured bid response. Common on larger projects; rare on small remodels.
An on-site visit where the contractor inspects the project space, asks questions, and refines their bid. Most traditional bidding processes require multiple walkthroughs across competing contractors.
A diagnostic test that pressurizes (or depressurizes) a home using a calibrated fan to measure air leakage. Results are reported as ACH50 (air changes per hour at 50 Pascals); modern energy-code construction targets ACH50 of 3 or lower.
A U.S. EPA / DOE certification program for energy-efficient products and homes. ENERGY STAR Certified Homes meet stricter envelope, HVAC, and water-heating standards than baseline code; certification typically adds 1–3% to construction cost.
The Home Energy Rating System Index, scale 0–150+, where lower is more efficient. A standard new home built to 2006 IECC scores ~100; a net-zero home scores 0. Used by the mortgage industry and ENERGY STAR certification.
The ACCA-published room-by-room heating and cooling load calculation used to size HVAC equipment. Required by most jurisdictions for new HVAC installs; oversized systems short-cycle, undersized systems can’t hit setpoint on design days.
Polyurethane insulation applied as a liquid that expands to fill cavities. Open-cell (~R-3.7/inch) is cheaper and breathable; closed-cell (~R-6.5/inch) acts as both insulation and air/vapor barrier. Adds 30–60% over fiberglass cost; pays back in tighter air-sealing.
A metal flashing installed at roof edges that directs water away from fascia and into the gutter. Required by IRC for most asphalt-shingle installs; failing or missing drip edge is a common cause of fascia rot and leaks.
A self-adhering waterproof membrane installed under shingles at eaves, valleys, and around penetrations. Required in northern climates for ice-dam protection; recommended everywhere for valleys and low-slope sections.
A continuous vent installed along the peak of a roof to exhaust attic air. Pairs with soffit intake vents for balanced ventilation; reduces shingle heat damage and prevents winter ice damming.
The water-resistant layer between roof sheathing and shingles. Synthetic underlayment (15- and 30-pound equivalents) has largely replaced traditional felt for durability and tear resistance.
The standard roofing measurement: 100 square feet of roof area. Quotes usually price per square (or "bundle" — 1/3 of a square). A typical 2,000 sq ft single-story home has 18–25 squares of roof depending on pitch and overhangs.
Chlorinated PVC, a rigid plastic used for hot- and cold-water supply lines. Cheaper than copper, suitable up to 200°F; widely used in the South. Becoming less common as PEX takes market share.
The U-shaped pipe under every fixture (sink, tub, shower) that holds water to block sewer gas from entering the home. Required by code on every drain; dried-out traps in unused drains are a common cause of sewer odors.
Flexible plastic tubing widely used for residential water-supply lines since the early 2000s. Faster to install than copper, freeze-tolerant, no-soldering, and 30–50% cheaper. PEX-A, PEX-B, and PEX-C differ in manufacturing process and fitting compatibility.
A pump installed in a basement or crawl-space pit to remove groundwater that collects there. Critical in flood-prone areas; battery-backup or water-powered backup pumps prevent failures during storm-related power outages.
An on-demand water heater that heats water as it flows through, eliminating storage-tank standby losses. Typically 25–30% more efficient than tank heaters and lasts 20+ years vs. 10–12, but installation cost is 2–3x higher and gas units may require a larger gas line and dedicated venting.
A protective device that detects unintended electrical arcs (from damaged wires, loose connections) and shuts the circuit off. Required by NEC on most residential branch circuits since 2014. Usually combined with GFCI in dual-function breakers.
The main breaker box that distributes power to circuits throughout the home. Common sizes: 100A (older homes, minimum for code in many areas), 200A (modern standard), 400A (large or all-electric homes). Upgrading typically runs $2,000–$5,000.
A protective device that detects ground faults (current leaking to ground through a person or wet surface) and shuts the circuit off in 1/40 of a second. Required by NEC at all wet locations: bathrooms, kitchens, exterior, garages, basements.
A secondary breaker panel fed from the main service panel, used to extend circuits to a detached structure (garage, ADU, workshop) or to add capacity in a crowded main. Requires a 4-wire feed and proper grounding/bonding rules.
Sealing a crawl space with a heavy-mil vapor barrier on the floor and walls, sealing vents, and adding a dehumidifier. Eliminates moisture, mold, and pest issues; especially valuable in humid coastal climates. Typical cost: $5,000–$15,000.
A concrete slab poured directly on prepared ground, with no basement or crawl space. Common in southern climates and modern construction. Cheaper and faster than basements, but plumbing changes after the pour are expensive.
Ducted systems push conditioned air through metal or flex ducts to floor/wall registers. Ductless (mini-split) systems deliver air directly into each room from a wall-mounted head. Ductless eliminates duct loss (~20% energy waste in typical homes) but requires visible indoor units.
Whole-house ventilation systems that exchange stale indoor air for fresh outdoor air while recovering heat (HRV) or heat-and-moisture (ERV) from the exhaust stream. Required for tightly-built modern homes to maintain indoor air quality.
An electric system that moves heat between indoors and outdoors for both heating and cooling. Modern cold-climate heat pumps work efficiently down to ~5°F. Air-source units cost $5K–$15K installed; geothermal $20K–$45K with payback in 8–15 years.
Engineering analysis (Manual J / D / S) used to size HVAC equipment, ducts, and registers for the specific home and climate. Good HVAC contractors run a full load calc; rule-of-thumb sizing leads to oversized equipment that short-cycles and wastes energy.
A heat pump with no central ductwork — wall-mounted indoor heads connected to an outdoor compressor by refrigerant lines. Ideal for additions, ADUs, garages, or homes without existing ducts. Typically $4K–$12K per zone installed.
Real hardwood veneer (1–6mm thick) bonded to a multi-layer plywood core. More dimensionally stable than solid hardwood, can be installed in basements and over radiant heat. $6–$14 per sq ft installed.
Multi-layer rigid vinyl flooring designed to look like wood or stone. Waterproof, scratch-resistant, $3–$8 per sq ft installed. Has largely replaced laminate as the budget-mid-range hard-floor choice; can be installed over most existing floors.
MDF (medium-density fiberboard) is made from compressed wood fibers + resin — smoother for paint, but vulnerable to moisture damage. Plywood is more moisture-resistant and screw-holding. Quality cabinets use plywood boxes with MDF doors painted; budget cabinets use particleboard throughout.
Quartz countertops are engineered (~93% ground quartz + resins), uniform appearance, non-porous, no sealing required. Quartzite is a natural stone with veining variation, harder than granite, requires sealing every 1–2 years. Quartz: $50–$120/sq ft installed; quartzite: $80–$200/sq ft.
Cabinet door style with a flat center panel and clean recessed frame around it. Most popular kitchen cabinet style of the past 20 years; works with traditional, transitional, and contemporary designs. Available across all price tiers.
Decking boards made from recycled wood fibers + plastic. No staining or sealing required, 25–50 year warranties. Costs $35–$60 per sq ft installed vs. $25–$40 for pressure-treated wood. Has captured the majority of the new-deck market.
Composite siding made of cement, sand, and cellulose fibers. Fire-resistant, rot-proof, holds paint 15–20 years. James Hardie is the dominant brand. Costs $9–$15 per sq ft installed — 2–3x vinyl, half the cost of stone or stucco.
Concrete pavers (interlocking blocks) cost $15–$35 per sq ft installed; failures can be repaired by lifting and re-leveling individual stones. Poured concrete costs $8–$18 per sq ft, but cracks require full slab replacement. Pavers also shed water faster — useful in stormwater-restricted jurisdictions.
Cellular PVC trim used in place of wood for fascia, soffit, window casings, and decorative exterior trim. Won’t rot, swell, or split; holds paint indefinitely. Costs 1.5–2x wood trim but eliminates repaint cycles every 5–7 years.
PVC siding panels that snap together. Cheapest exterior cladding ($4–$8 per sq ft), low maintenance, but lower-end perception. Premium insulated vinyl narrows the appearance gap with fiber cement at $7–$11 per sq ft.
A 240V home charging station for electric vehicles. Adds 25–40 miles of range per hour vs. ~5 miles/hour for a standard 120V outlet. Installation runs $500–$2,500 depending on panel capacity, distance from panel, and circuit upgrades needed.
Wi-Fi thermostat that learns occupancy patterns and allows remote control via app. Nest, Ecobee, and Honeywell dominate. Typical savings: 8–15% on heating/cooling bills. Many utilities offer rebates of $25–$100.
Roof-mounted (or ground-mounted) panels that convert sunlight to electricity. Typical residential systems: 6–10 kW, $15K–$30K before incentives. Federal tax credit covers 30% through 2032. Payback period 7–14 years depending on local electric rates and net-metering rules.
Permanently-installed natural gas or propane generator that auto-starts during outages. 18–22 kW units cover most residential loads; cost $8K–$18K installed. Common in coastal Virginia for hurricane resilience.
Lithium-ion battery (Tesla Powerwall, Enphase, Generac PWRcell) that powers the home during outages. Typical cost: $12K–$25K for one battery; 2 batteries needed to run AC plus essentials. Pairs naturally with solar PV.
A delivery model where one firm handles both design (architecture, interior design) and construction. Reduces homeowner coordination overhead and avoids design-vs-construction blame games, but limits independent design oversight.
A formal kickoff meeting between the homeowner, GC, project manager, and key subs before work starts. Reviews schedule, sub call-offs, communication protocol, jobsite rules (parking, hours, kid/pet considerations), and where on-site materials will stage. Skipping this is a common source of avoidable friction.
The walkthrough where the homeowner and contractor identify all remaining items needing attention before final payment. Typically follows substantial completion; the resulting punch list is tied to the final draw.
A structured review of a project’s scope to find cost reductions without compromising essential function. Common during the bidding phase when initial estimates exceed budget; well-managed VE preserves design intent, poorly-managed VE strips quality.
Publish a project brief on BidBro and you’ll see most of these terms in practice — bids broken into clean line items, allowances and contingencies called out, and lien waivers and COIs collected automatically as work progresses.