Glossary › Mechanicals
228 of 228 terms · A to Z
A higher-voltage circuit for ranges, dryers, EV chargers, and heat pumps. Adding one often needs panel space and a dedicated run.
The black (ABS) or white (PVC) plastic pipe used for modern drain and vent lines. Local code dictates which is allowed.
Source: Wikipedia — ABS/PVC DWV Pipe
Arc-Fault Circuit Interrupter — detects dangerous arcing that can start fires. Code now requires it on most living-space circuits; remodels must add it.
Annual Fuel Utilization Efficiency — the percent of fuel a furnace converts to usable heat over a year. 80% is mid-efficiency; 90–98% is condensing/high-efficiency.
Source: U.S. DOE — Furnaces and Boilers
A one-way vent valve allowing air in without a roof penetration, useful for islands and additions where running a vent is impractical (where code permits).
Source: Wikipedia — Air Admittance Valve
The blower unit moving air across the coil and through the ducts, paired with a heat pump or as part of an electric/hydronic system.
Source: Wikipedia — Air Handler
A budgeted dollar figure placeholder in the contract for an item not yet selected (e.g., tile, fixtures). If your final selection costs more than the allowance, you pay the difference — scrutinize low allowances in bids.
1960s–70s aluminum branch circuits prone to connection overheating. Requires approved remediation (e.g., COPALUM/AlumiConn) for safety.
Source: Wikipedia — Aluminum Wire
The home's total electrical capacity (commonly 100A, 150A, 200A). Kitchens, EV chargers, and heat pumps often force a 200A upgrade.
Source: Wikipedia — Ampere
A sacrificial rod inside a tank water heater that corrodes instead of the tank. Replacing it periodically greatly extends heater life.
A trade worker learning a craft through a structured program of paid on-the-job training and classroom instruction under journeymen, the standard path into the skilled trades.
Source: U.S. DOL — Apprenticeship.gov
Safety practices (de-energizing, lockout/tagout, PPE) for working on electrical systems. Why panel and service work is licensed, permitted trade work.
Source: Wikipedia — Arc Flash
The licensed architect legally responsible for the design documents submitted for permit, certifying the design meets applicable codes and standards.
Source: Wikipedia — Architect of Record
Updated drawings that reflect the project exactly as constructed, including all field changes — invaluable for future remodels and locating concealed utilities.
Source: Wikipedia — As-Built Drawing
Combustion gases (including CO) being pulled back into the house instead of up the flue, often from negative pressure caused by exhaust fans.
Source: Wikipedia — Flue Gas/Backdraft
A device stopping contaminated water from being siphoned back into the potable supply. Code-required at hose bibs, irrigation, and boilers.
A check valve in the building drain preventing municipal sewer backups from flooding the home. A recommended add in basement remodels.
Source: Wikipedia — Backwater Valve
A primary horizontal member that carries loads from joists or framing across a span to posts or walls. Opening up a floor plan usually means adding a sized beam.
Source: Wikipedia — Beam (Structure)
The recess in a wall or foundation that receives and bears the end of a beam. Cutting in new beam pockets is part of the cost when opening a load-bearing wall.
Source: Wikipedia — Beam (Structure)
A contractor's formal price proposal for a defined scope of work. Always compare multiple bids on the same written scope so you are comparing like for like, not just bottom-line numbers.
Source: Merriam-Webster — Bid
A fan-and-gauge test measuring whole-house air leakage. Code increasingly requires a passing result after major remodels.
Source: Wikipedia — Blower Door
A heating appliance that heats water for radiators, baseboard, or radiant floors (hydronic heat) rather than blowing warm air.
A surety bond is a guarantee from a third party that the contractor will complete the work (performance bond) or pay subs and suppliers (payment bond). Bonding is a sign of contractor financial stability.
Source: Cornell Law LII — Surety
Tying metallic systems together so they can't carry a dangerous voltage difference. Specific bonding is required for gas piping, water lines, and pools.
Source: Wikipedia — Electrical Bonding
The NEC limit on how many conductors/devices fit in an electrical box. Overfilled boxes overheat and are a common inspection failure.
Wiring from a breaker to the outlets/devices it serves. Circuit count and dedicated circuits are core to any kitchen, bath, or addition.
Finishing the interior of a commercial shell or tenant space to suit a specific occupant — partitions, ceilings, lighting, HVAC distribution, finishes and fixtures. The scope is usually spelled out in the lease as tenant improvements.
Source: Wikipedia — Tenant Improvement
The set of minimum legal standards for safe construction adopted by your jurisdiction (in Ohio, based on the International Residential Code). Work must meet code to pass inspection and protect resale.
Source: Wikipedia — Building Code
The main drain leaving the house to the city sewer or septic. Aging clay/cast laterals are a major hidden-cost risk in older homes.
Source: Wikipedia — Sewer Lateral
Running a camera down the sewer lateral to find breaks, bellies, or root intrusion before they become an emergency — wise before a major remodel.
Source: Wikipedia — Sanitary Sewer
Colorless toxic gas from incomplete combustion. Cracked exchangers, backdrafting, and bad venting cause it — driving CO-alarm and venting code rules.
Source: U.S. EPA — Carbon Monoxide
A skilled tradesperson who constructs, installs, and repairs structures and fixtures from wood and other materials — framing, trim, cabinetry, and finish work.
Source: U.S. BLS — Carpenters
Older quiet but corrodible drain piping. Deteriorated cast iron under slabs/in stacks is a common reason for invasive plumbing work.
Source: Wikipedia — Cast Iron Pipe
A flexible sealant used to close gaps and joints against air and water (around trim, tubs, counters). The right caulk for the location matters — kitchen/bath joints need a mildew-resistant silicone.
Source: Wikipedia — Caulk
A rigid cement-based panel used as a stable, water-durable substrate for tile in wet areas — preferred over drywall behind tile in showers and on counters.
Source: Wikipedia — Cement Board
A split system with an outdoor condenser and indoor coil that cools the whole house through the existing ductwork.
A document issued by the building department certifying a structure complies with code and is safe to occupy. Often required after major remodels and before a property can be legally sold.
A written, signed amendment that adds, removes, or modifies work after the contract is signed, adjusting price and schedule accordingly. Verbal changes are the leading cause of remodel disputes — get every change in writing.
Source: Wikipedia — Change Order
An automatic switch that interrupts a circuit on overload or short, resettable unlike a fuse. The modern overcurrent device.
Source: Wikipedia — Circuit Breaker
A capped access fitting for snaking/clearing the drain line. Code requires them at intervals and direction changes.
Outside air a fuel-burning appliance needs to burn safely. Tightening a house without providing it can cause backdrafting and CO risk.
Requirements ensuring fuel appliances get enough air in confined spaces (e.g., a furnace closet). Tightening the envelope can trigger this.
Atmospheric, power-vent, or direct-vent options for gas water heaters. Switching types during a remodel affects venting and combustion-air work.
Source: U.S. DOE — Water Heating
Meeting all applicable codes, permit conditions, and regulations for the work performed. Documented compliance is what protects you at resale and with insurers.
Source: Merriam-Webster — Compliance
A mix of cement, aggregate, and water that cures into a hard structural material used for footings, slabs, and foundations. Curing time affects schedule on any structural work.
Source: Wikipedia — Concrete
The line removing water the AC coil pulls from the air. Clogs cause overflow and water damage; a safety float switch is recommended.
Source: Wikipedia — Air Conditioning
The outdoor unit that rejects heat removed from the house. Needs clearance and airflow; undersizing or dirty coils kill efficiency.
Source: Wikipedia — Air Conditioning
A high-efficiency (90%+ AFUE) furnace that extracts extra heat from exhaust, producing acidic condensate that needs a drain and PVC venting.
Source: U.S. DOE — Furnaces and Boilers
Protective tubing (EMT, PVC) for wiring in exposed, exterior, or damp locations and where code requires physical protection.
Source: Wikipedia — Electrical Conduit
A reserve (typically 10–15% of project cost) set aside for hidden conditions and surprises uncovered once work begins. The line clients most want to skip and most often need.
Source: Investopedia — Contingency
The legally binding agreement between owner and contractor that defines scope, price, schedule, and responsibilities. A remodel should never start on a handshake — the contract is your primary protection.
Source: Cornell Law LII — Contract
The full set of papers that together form the agreement — the signed contract, drawings, specifications, scope of work, allowances, and any addenda. All of it governs the job, not just the signature page.
Source: Wikipedia — Contract
The person the contractor names as its single point of contact for the owner for the life of the job. At iSpec that is the project manager who takes the first call: the liaison between the owner, the designer and the crew, with a skilled-trades lead running the site day to day and reporting to them.
Source: AIA — A201 General Conditions of the Contract for Construction
Durable, long-proven supply piping (types L/M). More costly and labor-intensive than PEX; still specified where preferred or required.
Source: Wikipedia — Copper Tubing
Two contract structures: fixed-price (lump sum, contractor bears overrun risk) versus cost-plus (owner pays actual costs plus a fee, owner bears overrun risk). Each shifts risk and pricing transparency differently.
Chlorinated PVC supply pipe rated for hot and cold water; an alternative to copper/PEX in some regions.
Source: Wikipedia — CPVC
A shallow accessible void below the floor (instead of a basement or slab) housing structure, plumbing, and ducts. Its condition affects access cost and moisture risk on remodels.
Source: Wikipedia — Crawl Space
An adjustable plate in a duct that balances or shuts off airflow to a zone or branch.
Source: Wikipedia — Damper (Flow)
The roll-off container for construction waste. Placement, permits for street placement, and haul-away are real line items and logistics on any sizeable remodel.
Source: Wikipedia — Roll-Off (Dumpster)
A circuit serving one appliance only (e.g., range, dryer, microwave, EV charger). Required by code for many large or motor loads.
Source: Wikipedia — Electrical Wiring
A ducted unit removing humidity in muggy climates/basements for comfort and mold control beyond what AC alone provides.
Source: Wikipedia — Dehumidifier
The controlled removal of existing finishes and structure to prepare for new work. A clean, properly contained demo is where most hidden conditions (rot, old wiring, mold) are first uncovered.
Source: Wikipedia — Demolition
A delivery method where one entity handles both design and construction under a single contract, giving the owner one point of responsibility and tighter cost/design feedback.
Source: Wikipedia — Design–Build
A control varying light level. Must be compatible with the bulb/driver type (LED-rated) to avoid flicker and buzz.
Source: Wikipedia — Dimmer
The system carrying waste out and venting the drains so traps hold their seal. The hardest part to relocate in a remodel.
The agreed timeline of payments tied to completed project milestones rather than calendar dates. A fair draw schedule keeps payments slightly behind the work completed, never ahead of it.
Source: Investopedia — Construction Loan
The coordinated package of plans — floor plans, elevations, sections, and details — that defines the design and governs construction and permitting.
Gypsum panel wall and ceiling material (also called sheetrock) that is hung, taped, mudded, and finished. Any wall opened during a remodel needs drywall repair and finish.
Source: Wikipedia — Drywall
A heat pump paired with a gas furnace that switches to gas in extreme cold for the most cost-effective heating across the season.
Source: U.S. DOE — Heat Pump Systems
Mastic/foil-tape sealing of duct joints to stop leakage (often 20–30% of conditioned air). One of the highest-ROI efficiency improvements.
Source: Wikipedia — Duct (Flow)
A heat pump with an outdoor unit and wall/ceiling indoor heads, no ductwork. Ideal for additions, conversions, and zoning specific rooms.
The supply/return passages distributing conditioned air. Leaky or undersized ducts are a top cause of comfort and efficiency complaints.
Source: Wikipedia — Duct (Flow)
Temporary barriers, zip walls, and negative-air setups that keep demolition and sanding dust out of occupied areas. Standard practice for live-in remodels and required where lead is present.
A recorded legal right for someone else (often a utility) to use part of your land. Building over an easement can force removal at your expense — check the survey before adding structures.
Source: Cornell Law LII — Easement
A code-required path of exit from a space in an emergency. Bedrooms and finished basements require a compliant egress window or door of minimum size and reachable height.
Source: Wikipedia — Egress Window
Baseboard, wall, or furnace strip heat that converts electricity directly to heat. 100% efficient at the unit but expensive to run versus a heat pump.
A licensed tradesperson who installs and maintains wiring, panels, circuits, and devices to code. Remodels that add circuits or move panels require a licensed electrician and inspection.
Source: U.S. BLS — Electricians
Replacing fossil-fuel HVAC/water heating with heat pumps. Often paired with a panel/service upgrade and may qualify for IRA tax credits and rebates.
Source: U.S. DOE — Heat Pump Systems
A flat, straight-on drawing of one face of a structure or wall (e.g., a kitchen wall elevation) showing heights and vertical relationships that a plan view cannot.
A professional assessment (often with a blower door) identifying the highest-ROI efficiency improvements before a mechanical remodel.
Source: U.S. DOE — Home Energy Audits
Energy/Heat Recovery Ventilators that supply fresh air while recovering heat (and, for ERV, humidity) from exhaust. Key for tight, healthy homes.
The indoor coil (usually atop the furnace) where refrigerant absorbs heat from house air. Paired and matched to the condenser.
Source: Wikipedia — Air Conditioning
Earth removal for foundations, footings, or utilities. Regulated for cave-in safety and requires utility locating before digging.
A small tank absorbing thermal expansion on a closed system (with a backflow preventer/PRV). Code-required in many areas to protect the heater and plumbing.
Source: Wikipedia — Expansion Tank
The conductors carrying power from the main panel to a subpanel or large appliance disconnect.
A table in the drawings specifying the exact finish for every surface in every room — flooring, wall, ceiling, trim — so selections are documented, not assumed.
How much hot water a heater delivers in a peak hour (tank) or gallons-per-minute (tankless). The right sizing metric, not just tank gallons.
Source: U.S. DOE — Sizing a Water Heater
Thin water-resistant material installed at joints and transitions (roof-to-wall, around windows and penetrations) to direct water away and prevent leaks into the assembly.
A scaled overhead view of a level showing walls, rooms, openings, and fixture locations. The primary drawing for understanding layout and flow.
Source: Wikipedia — Floor Plan
The pipe carrying combustion gases safely outside. Improper sizing, slope, or material is a serious carbon-monoxide hazard.
Source: Wikipedia — Flue
The widened concrete base below a foundation wall or post that spreads the structure's load over enough soil to prevent settling. New structural posts require their own footings.
The lead worker who directs a specific crew or trade on site, working alongside the team while ensuring the work meets plan and schedule.
Source: Wikipedia — Construction Foreman
The structure (slab, crawl space, or basement) that transfers the building's load to the ground. Foundation condition underlies the feasibility and cost of major remodels.
The skeleton of wood or steel members — studs, joists, rafters, beams — that gives a structure its shape and carries its loads before finishes go on.
Switching an appliance/home between gas, propane, and electric. Affects venting, gas sizing, electrical service, and rebate eligibility.
Source: U.S. DOE — Home Heating Systems
A forced-air heater burning gas/oil or using electric elements, distributing heat through ductwork. The most common U.S. central heating system.
Thin strips fastened to a wall or ceiling to create a level, plumb nailing surface or an air gap before finish material is applied — common over masonry or uneven framing.
Source: Wikipedia — Furring
Old zinc-coated steel supply pipe that corrodes and restricts flow internally. A common reason older homes need a repipe.
Fuel gas piping (black iron or flexible CSST). Adding a range, pro cooktop, tankless heater, or fireplace often requires sizing/extending it.
The utility meter and supply sized to total appliance demand. High-BTU additions can exceed capacity and require a utility upgrade.
Source: Wikipedia — Gas Meter
The party responsible for the overall project — scheduling, hiring and managing subcontractors, pulling permits, and delivering the finished job. Your single point of accountability.
Source: Wikipedia — General Contractor
A ground-source heat pump exchanging heat with stable earth temperatures via buried loops — very efficient, high install cost.
Source: U.S. DOE — Geothermal Heat Pumps
Ground-Fault Circuit Interrupter — cuts power on a small leakage current near water. Code-required at kitchens, baths, garages, exteriors, and more.
Shaping the ground around a structure so water drains away from the foundation. Poor grading is a leading cause of basement and crawl-space water problems.
Source: Wikipedia — Grading (Earthworks)
The system tying metal parts and the neutral to earth so faults trip breakers safely. Improper bonding is a shock and fire hazard.
Source: Wikipedia — Ground (Electricity)
The ground rod(s) or rebar/water-pipe connection establishing the earth reference for the electrical system.
Source: Wikipedia — Grounding Electrode
The material that fills and seals joints between tiles. Sanded, unsanded, and epoxy grouts differ in durability and stain resistance — epoxy is the premium choice in wet, high-use areas.
Source: Wikipedia — Grout
The tangible construction costs — labor, materials, equipment — as opposed to soft costs like design fees, permits, and financing. Hard costs are the bulk of a remodel budget.
Source: Investopedia — Hard Cost
A condition or activity with potential to cause harm — electrical, structural, dust, fall, or material (lead, asbestos). Identifying hazards before demo drives containment and cost.
A horizontal structural member spanning the top of an opening (door, window, cased opening) that transfers the load above around the opening to the supports on each side.
Source: Wikipedia — Lintel (Header)
The furnace component that transfers combustion heat to household air while keeping flue gases separate. A cracked heat exchanger is a carbon-monoxide hazard requiring replacement.
Source: Wikipedia — Heat Exchanger
An electric system that moves heat instead of burning fuel, providing both heating and cooling. Highly efficient; cold-climate models now perform well in winter.
Source: U.S. DOE — Heat Pump Systems
A hybrid tank that pulls heat from surrounding air — 2–3x more efficient than electric resistance. Needs space and produces cool exhaust air.
An exterior faucet; frost-free types extend the valve inside the wall to prevent freeze-burst. A common winter failure point.
Source: Wikipedia — Tap (Hose Bib)
The current heating-season efficiency rating for heat pumps (replaced HSPF in 2023). Higher means more heat per unit of electricity.
Source: U.S. DOE — Heat Pump Systems
A unit added to the furnace adding moisture in winter for comfort and to protect woodwork and floors.
Source: Wikipedia — Humidifier
Heating that circulates hot water through baseboard, radiators, or floor tubing. Comfortable and quiet; slower to respond than forced air.
Source: Wikipedia — Hydronics
A code official's review of work at defined stages (rough-in, framing, final) to verify compliance before the next phase can proceed. Failed inspections stop the job until corrected.
Source: Wikipedia — Building Inspection
Material that resists heat flow, rated by R-value, installed in walls, ceilings, and floors. Opened walls are the opportunity to upgrade insulation while it is accessible.
Source: U.S. DOE — Insulation
One of the repetitive horizontal members that support a floor or ceiling, spanning between beams or walls. Joist size, spacing, and direction govern what you can cut or load.
Source: Wikipedia — Joist
An enclosure where wires connect; all splices must be in an accessible box, never buried in a wall. A common code violation in DIY work.
Source: Wikipedia — Junction Box
A short wall, typically under a sloped roof or supporting a counter or railing, that is less than full ceiling height.
Source: Wikipedia — Knee Wall
Obsolete early-1900s wiring with no ground. Often must be replaced during remodels and can affect insurance and insulation.
Source: Wikipedia — Knob-and-Tube Wiring
A legal claim against your property for unpaid work or materials. A mechanic's lien filed by an unpaid subcontractor can cloud your title even if you already paid the general contractor.
Source: Cornell Law LII — Lien
A signed document in which a contractor or supplier gives up the right to file a lien for a given payment. Collect lien waivers with each payment to protect against double-payment claims.
Source: Investopedia — Lien Waiver
The insulated copper tubing connecting the outdoor condenser to the indoor coil. Replaced or flushed when changing refrigerant type.
Source: Wikipedia — Air Conditioning
A pre-agreed dollar amount the contractor owes the owner for each day a project runs past the contracted completion date. Must be a reasonable estimate of actual loss, not a penalty.
An NEC calculation of total demand to verify the service/panel can carry added loads. The basis for whether a service upgrade is required.
Installing equipment larger than the calculated load — a frequent mistake that causes short cycling, poor dehumidification, and higher cost.
Source: Wikipedia — Heating/Cooling Load
A wall that carries weight from the structure above down to the foundation. Removing or opening one requires an engineered beam and posts — never assume a wall is non-bearing.
Source: Wikipedia — Load-Bearing Wall
The single breaker that disconnects the entire panel and caps total service amperage.
Source: Wikipedia — Circuit Breaker
The valve stopping all water to the house. Every homeowner should know its location; remodels often add accessible zone shutoffs.
Source: Wikipedia — Valve (Shutoff)
Replacement outdoor air supplied when powerful exhaust (large range hoods, whole-house fans) depressurizes a house. Code-required above set exhaust rates.
Source: Wikipedia — Makeup Air Unit
A PEX distribution method with individual lines from a central manifold to each fixture, improving pressure balance and isolation.
The industry-standard room-by-room heating/cooling load calculation that correctly sizes equipment. The right basis for any system replacement.
Source: Wikipedia — Heating/Cooling Load
Mechanical, Electrical and Plumbing — the three building-systems trades (HVAC, wiring, water and drain lines) roughed in after framing and before drywall. On a remodel, MEP rough-in is where most of the hidden cost and most of the inspections live.
Minimum Efficiency Reporting Value — a filter's particle-capture rating (1–16). Higher filters more but can choke airflow if the system isn't designed for it.
Source: U.S. EPA — MERV Rating
The utility meter socket on the service entrance; replaced or relocated as part of a service upgrade.
Source: Wikipedia — Electricity Meter
Shop-made wood products installed as finish carpentry — trim, casing, baseboard, crown, built-ins, stair parts, doors and cabinetry. Distinct from rough framing lumber; the quality of the millwork is what the eye reads as a finished room.
Source: Wikipedia — Millwork
A cement-based paste used to bond masonry or, as thinset, to adhere tile to a substrate. Different mixes are rated for different applications and exposures.
Source: Wikipedia — Mortar (Masonry)
The model electrical safety code adopted (with amendments) by jurisdictions. Permitted electrical work must meet the adopted NEC edition.
Building a structure from the ground up on an empty or cleared site, as opposed to remodeling or adding onto an existing one. Site work, foundation, framing and every trade follow in sequence, so the big design decisions are made before a shovel hits the ground.
Source: Wikipedia — Construction
Oriented strand board — an engineered panel of compressed wood strands and resin, commonly used for sheathing and subfloor. Cheaper than plywood but less moisture-tolerant.
The Occupational Safety and Health Administration — the federal agency setting and enforcing job-site safety standards. A contractor's safety record is a meaningful screening signal.
Source: U.S. OSHA — Occupational Safety & Health Administration
The person the owner names to make decisions and answer questions on the owner's behalf — the homeowner, one spouse, an investor's local agent or a hired consultant. Naming one at the pre-construction conference keeps decisions and change orders running between two people, so nothing is decided twice or by the wrong person.
Source: WBDG — Project Delivery Teams
The U-bend at each fixture holding water that blocks sewer gas from entering the home. Every fixture needs one, properly vented.
Source: Wikipedia — Trap (Plumbing)
A non-load-bearing interior wall that divides space but carries no structural load above it. Generally simpler and cheaper to move than a bearing wall.
Source: Wikipedia — Partition Wall
Official jurisdiction authorization to perform regulated work, triggering required inspections. Unpermitted remodels can force teardown, block sale, and void insurance — always confirm permits are pulled.
Source: Wikipedia — Building Permit
HVAC, gas, electrical, and plumbing work is permitted, inspected trade work. Unpermitted mechanical work is a safety and resale liability.
Source: Wikipedia — Building Inspection
Cross-linked polyethylene supply tubing — flexible, freeze-tolerant, fast to install with fewer joints. The dominant modern repipe material.
The main air chamber off the furnace/air handler from which supply ducts branch and into which the return delivers.
Source: Wikipedia — Plenum Chamber
A licensed tradesperson who installs and repairs water supply, drain-waste-vent, and gas piping to code. Relocating fixtures or running new lines is licensed, inspected work.
An engineered panel of thin wood veneers glued in cross-grain layers for strength and stability. Preferred over OSB for cabinet boxes and where moisture exposure is a concern.
Source: Wikipedia — Plywood
A preparatory coating that seals the surface and helps the finish coat adhere and cover evenly. Skipping primer over new drywall or stains causes finish failures.
Source: Wikipedia — Primer (Paint)
An invoice issued while a project is under way for the work completed in that period, as opposed to a single bill at the end. Progress invoicing is typically weekly on a remodel; on larger or lender-financed jobs the contract may set a milestone draw schedule instead.
Source: FAR 52.232-5 — Payments Under Fixed-Price Construction Contracts
The person who plans, coordinates, and oversees the project day to day — schedule, budget, subs, and communication with the owner. On smaller jobs the GC and PM may be the same person.
The final list of incomplete or deficient items the contractor must correct before the job is considered done and final payment is released. Walk the project and build this list together.
Source: Wikipedia — Punch List
Warming a space via tubing or electric mats under the floor. Even, comfortable heat; best designed in during a remodel when floors are open.
Source: U.S. DOE — Radiant Heating
The point devices plug into. Tamper-resistant receptacles are now code in dwellings; spacing rules govern how many a remodel must add.
Source: Wikipedia — Receptacle/Outlet
Ceiling-flush lighting on a planned grid. IC-rated/airtight housings are required in insulated ceilings to prevent heat and air-leak issues.
Source: Wikipedia — Recessed Light
A pump delivering near-instant hot water at fixtures by keeping the line warm. Saves water; adds energy unless on a timer/demand control.
Source: Wikipedia — Water Heating
The working fluid that carries heat in an AC/heat pump. R-410A is being phased down to lower-GWP refrigerants (e.g., R-454B) under EPA rules.
The supply outlet (register, with damper) and return inlet (grille) terminating the duct in each room.
Changing the structure, layout or function of an existing space — moving walls, relocating a kitchen, adding a bath — rather than simply refreshing finishes. More involved than a cosmetic renovation because it usually touches framing, plumbing and electrical behind the walls.
Source: Wikipedia — Renovation
A percentage of each payment (often 5–10%) the owner withholds until the project is satisfactorily completed, providing leverage to ensure the job is finished and punch-listed.
Source: Investopedia — Retainage
Ducting that draws room air back to the system. Insufficient return is a common cause of weak airflow and short-cycling.
Source: Wikipedia — Duct (Flow)
A formal written question from the builder to the designer or owner to clarify drawings or specs before proceeding. RFIs create a paper trail that prevents costly assumptions.
Non-metallic sheathed cable, the common residential branch wiring. Gauge must match the breaker (14 AWG/15A, 12 AWG/20A).
Source: Wikipedia — NM Cable
The framed gap left in a wall to receive a window, door, or unit, sized slightly larger than the product to allow shimming and squaring during installation.
The stage where plumbing, electrical, and HVAC lines are run inside open walls and floors before insulation and drywall. Rough-in must pass inspection before walls are closed.
A temporary elevated work platform system. Proper scaffolding is a regulated safety item on multi-story exterior and high-ceiling interior work.
Source: U.S. OSHA — Scaffolding
The detailed written description of exactly what the contractor will and will not do on the project. The single most important document for preventing misunderstandings and 'I thought that was included' arguments.
A material applied to a surface or joint to block the passage of water, air, or stains. Stone counters, grout, and exterior penetrations are commonly sealed.
Source: Wikipedia — Sealant
A drawing showing the structure as if sliced vertically, revealing how floors, walls, and roof assemble and stack — used to communicate construction detail.
A short capped pipe at a gas appliance that catches debris/condensate before it reaches the valve. Code-required and a common inspection item.
Source: Wikipedia — Gas Piping
The current seasonal cooling-efficiency rating for AC and heat pumps (replaced SEER in 2023). Higher SEER2 means lower cooling energy use.
Work a general contractor does with its own crew rather than through a subcontractor — on a kitchen or bath, typically demolition, framing, drywall, tile, cabinets, trim and fixture swaps. A self-performing contractor keeps small projects affordable because each trade is not carrying a separate subcontractor's overhead; licensed plumbing, electrical and HVAC are still subcontracted when the layout or mechanicals change.
Source: FAR 52.236-1 — Performance of Work by the Contractor
Where utility power enters the home — drop/lateral, meter, and main disconnect. Upgrading it is often the gating cost when adding major loads.
Source: Wikipedia — Electrical Wiring
The breaker box distributing power to circuits. Capacity (e.g., 100 vs. 200 amp) and free breaker spaces decide what a remodel can add.
The minimum required distance between a structure and the property line, street, or other features. Setbacks constrain where additions, decks, and detached structures can be placed.
Source: Wikipedia — Setback (Land Use)
A pump moving waste up from below-sewer-level fixtures (basement bath) to the building drain. Required when adding a basement bathroom.
Source: Wikipedia — Sanitary Sewer
The structural panel layer (plywood or OSB) attached to studs or rafters that braces the frame and provides a base for siding, roofing, or finishes.
Source: Wikipedia — Sheathing
Equipment turning on and off too frequently — usually from oversizing or airflow problems — causing wear, poor comfort, and high bills.
Source: Wikipedia — Air Conditioning
The local valve at each fixture allowing isolated repair without shutting the whole house. Adding/replacing them is standard during remodels.
Source: Wikipedia — Valve (Stop)
A poured concrete floor or foundation surface. Moving plumbing in a slab-on-grade home means saw-cutting and patching concrete — a significant cost driver.
Source: Wikipedia — Concrete Slab
Drain pipe must pitch about 1/4 in. per foot — too little won't clear solids, too much drains liquid off solids. A frequent DIY error.
Source: Wikipedia — Drain Slope
A Wi-Fi/Z-Wave switch for app/voice/scheduled control. Many need a neutral wire in the box — a constraint in older homes.
A learning/Wi-Fi thermostat with scheduling, remote control, and usage reporting; many qualify for utility rebates.
Source: ENERGY STAR — Smart Thermostats
Code rules for interconnected smoke and carbon-monoxide alarms that a remodel of a sleeping area or fuel appliance typically triggers.
Source: Wikipedia — Smoke/CO Detector
The main vertical drain carrying waste from toilets and fixtures down to the building drain.
Source: Wikipedia — Soil Stack
Resistance to airflow in the duct system. High static (undersized ducts, dirty filter) overworks the blower and cuts capacity.
Source: Wikipedia — Duct (Flow)
An official order halting construction, usually for working without a permit or a code/safety violation. Work cannot resume until the issue is resolved and the order is lifted.
Source: Wikipedia — Building Inspection
A vertical framing member in a wall (typically 2x4 or 2x6) spaced 16 or 24 inches on center, forming the structure to which sheathing and drywall attach.
Source: Wikipedia — Wall Stud
A specialized trade (electrician, plumber, tile setter) hired by the general contractor to perform a portion of the work. You contract with the GC, not the subs.
Source: Wikipedia — Subcontractor
The structural sheet material (plywood or OSB) fastened over floor joists that everything else — underlayment and finish flooring — is built on. Squeaks and unevenness usually start here.
Source: Wikipedia — Subfloor
Product data, samples, or shop drawings the contractor submits for approval before ordering or installing, confirming what will actually be used matches the specification.
A secondary panel fed from the main, adding circuits for a remodel, addition, garage, or shop. Requires correct 4-wire feeder and isolated neutrals.
The on-site supervisor who runs the field operation — directing crews, sequencing trades, and enforcing safety and quality at the job site.
The temperature-and-pressure safety valve on a water heater that prevents tank rupture. Must discharge per code; never plugged.
Source: Wikipedia — Relief Valve (T&P)
The process of measuring quantities of materials and labor from the drawings to build an estimate. Accurate takeoffs are the foundation of an accurate bid.
Source: Wikipedia — Cost Estimate
An outlet with internal shutters preventing object insertion, code-required in dwelling living spaces.
A storage water heater keeping a tank hot. Lowest upfront cost; standby losses and limited capacity are the trade-offs.
Source: U.S. DOE — Water Heating
An on-demand heater with endless hot water and no standby loss. Higher install cost; gas units often need larger gas/vent lines.
The control that calls for heating/cooling. Programmable and smart models cut energy by matching conditioning to occupancy.
Source: U.S. DOE — Thermostats
Switches controlling one fixture from two or more locations (stairs, long rooms). Adds wiring complexity in a remodel.
Source: Wikipedia — Multiway Switching
A billing arrangement where the customer pays the crew's actual hours at a stated hourly rate plus the materials and equipment used, invoiced as the work is completed rather than as a fixed price. iSpec bills its own crew's work this way, with nothing added on top of the hourly rate; subcontracted trades are billed cost-plus.
AC/heat-pump cooling capacity (1 ton = 12,000 BTU/hr). Sized by a load calculation, not square footage rules of thumb — oversizing hurts comfort and humidity control.
Source: Wikipedia — Ton of Refrigeration
Equipment that runs at partial capacity most of the time for efficiency and comfort, ramping up only on extreme days.
Source: U.S. DOE — Furnaces and Boilers
The standardized water-heater efficiency metric for comparing models; higher UEF means less energy per gallon delivered.
Source: U.S. DOE — Water Heating
Reviewing the design to find lower-cost ways to achieve the same function and quality — substituting materials or methods to bring a project back within budget without gutting its goals.
Source: Wikipedia — Value Engineering
A material that limits moisture diffusion through an assembly to control condensation. Correct placement is climate-dependent — wrong-side vapor barriers trap moisture and cause rot.
Source: Wikipedia — Vapor Barrier
An ECM blower that ramps output to match demand for steadier temperatures, better humidity control, and lower electricity use than single-speed.
Source: U.S. DOE — Furnaces and Boilers
Official permission to deviate from a zoning requirement (e.g., to build closer to a property line than the setback allows). Requires application and usually a hearing.
Source: Cornell Law LII — Variance
A thin layer of a finish material bonded to a cheaper substrate — wood veneer on cabinet panels, stone or brick veneer on walls — delivering the look without the solid-material cost.
Source: Wikipedia — Wood Veneer
The piping admitting air so drains flow without siphoning traps, terminating through the roof. Adding fixtures often means new venting.
Source: Wikipedia — Vent Stack
Gases emitted by some paints, finishes, and adhesives that affect indoor air quality. Low- and zero-VOC products are widely available and recommended for occupied remodels.
The bang when fast-closing valves stop flow; an arrestor cushions it to protect pipes and joints.
Source: Wikipedia — Water Hammer
Household pressure (ideally ~50–70 psi). A pressure-reducing valve protects fixtures where street pressure is too high.
The pipe from the municipal main or well to the house. Old galvanized or lead service lines are often replaced during major remodels.
Source: Wikipedia — Water Supply Network
Equipment that removes hardness minerals to protect pipes, fixtures, and water heaters. Often added during a plumbing remodel.
Source: Wikipedia — Water Softening
Point-of-entry treatment (sediment/carbon) for all household water, plumbed at the service entrance.
Source: Wikipedia — Water Filter
A panel-mounted device clamping voltage spikes to protect all home electronics. Now required by code on service upgrades in many areas.
Source: Wikipedia — Surge Protector
A planned system delivering fresh outdoor air, increasingly required as homes are built and remodeled tighter.
The American Wire Gauge sizing of conductors to their amperage. Undersized wire on a too-large breaker is a fire hazard.
Source: Wikipedia — American Wire Gauge
Required clear space in front of a panel (about 36 in. deep, 30 in. wide). Remodels can't bury or block a panel.
A house stuck between owners: the occupant left — often after a foreclosure filing — but the foreclosure stalled or the taxes went unpaid, so nobody maintained it. In Columbus they reach the market through sheriff's auctions, the Franklin County land bank and as-is sales, usually without an inspection before purchase. The rehab is a whole-home gut remodel with every system assumed dead until proven otherwise.
Source: Central Ohio Community Improvement Corporation (Franklin County Land Bank) — About
Local laws governing how land may be used and what can be built where, including size, height, and setback limits. Additions and footprint changes often require zoning review.
Source: Cornell Law LII — Zoning
Dampers and thermostats dividing a house into independently controlled areas for comfort and efficiency, common with two-story homes.
Source: U.S. DOE — Zoning/Thermostats
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