Glossary
The vocabulary of restaurant conversion.
The technical language of a restaurant permit set — BTU, MUA, NFPA 96, Type I hood, AHJ, IECC, plan check — in plain English. Bookmark this page; every guide and blog post on this site deep-links here so a defined term is always one click away.
Mechanical
Mechanical terms
- BTU (British Thermal Unit)· BTU
- A unit of heat. Gas cooking appliances are rated by input in BTU per hour (BTU/h): a home burner is roughly 12,000 BTU/h; a commercial wok burner typically 100,000–150,000 BTU/h.
- CFM (Cubic Feet per Minute)· CFM
- The volumetric flow rate of an exhaust hood or make-up air unit. A typical commercial pizza hood pulls 1,500–2,500 CFM; a high-BTU wok hood can pull 4,000+ CFM.
- Make-Up Air· MUA
- Outside air brought in to replace what the hood exhausts. The mechanical code requires make-up air roughly equal to the exhaust (IMC 508.1); a dedicated, tempered unit typically supplies most of it, the rest transferred from the dining room.
- Type I Hood
- A grease-rated commercial hood with grease filters and a fire-suppression system, built of steel or stainless steel. The mechanical code requires one where appliances produce grease or smoke (IMC 507; UMC Chapter 5); NFPA 96 sets matching hood, duct and suppression rules.
- Type II Hood
- A hood for appliances that give off heat, steam or combustion products but no grease or smoke — dishwashers and some ovens, kettles and steamers (IMC 507.3). Some small electric appliances are exempt when the HVAC design handles their heat and moisture.
- Capture Velocity
- The air speed needed at the hood edge to pull in rising cooking effluent. Codes set no single capture-velocity number: unlisted hoods use the mechanical code’s minimum CFM per linear foot (IMC 507), listed hoods their listed airflow, and a capture-and-containment test confirms it.
- Ember Collector
- A baffle or screen assembly in a solid-fuel hood, ahead of the grease filters, that stops sparks and embers — what NFPA 96 calls a spark arrester.
- Spark Arrester
- A screen or baffle that keeps sparks and embers from solid-fuel cooking out of the hood plenum and grease duct — or, where there is no hood, out of the flue or chimney (NFPA 96).
- Climate Zone
- The ASHRAE / IECC climate classification (zones 0–8, with moisture subtypes) used to set envelope, HVAC, and energy compliance paths. Phoenix is 2B (hot-dry); Houston is 2A (hot-humid).
Why it matters: Hood, MUA, gas-line, and meter sizing all flow from total BTU load; under-sizing it can force a new hood, make-up air unit, or gas service late in the job.
Link →Why it matters: For unlisted hoods, the mechanical code sets minimum exhaust per linear foot of hood by appliance duty (IMC 507); listed hoods run at their listed rate. A sandwich-line hood rarely meets a wok line’s rate.
Link →Why it matters: Without MUA, the hood pulls negative pressure through the front door — slamming it, chasing customers out, and starving combustion appliances of oxygen.
Link →Why it matters: Almost every restaurant conversion needs at least one Type I hood; some need two (gas-line + solid-fuel) because they cannot share ductwork.
Link →Why it matters: Where an appliance gives off only heat and steam, a Type II hood (or a code exemption) can replace a far costlier Type I — confirm the appliance’s duty class with the mechanical reviewer.
Link →Why it matters: A hood at the right CFM can still fail its capture test if hood size, overhang or make-up air delivery is wrong.
Link →Why it matters: NFPA 96 requires spark arresters for solid-fuel cooking, and solid-fuel exhaust must be separate from all other exhaust — so an existing gas-line hood can’t serve a wood-fired oven.
Link →Why it matters: Required for solid-fuel cooking under NFPA 96; inherited gas-line hoods don’t have them.
Link →Why it matters: Same hood schedule needs different MUA tempering depending on climate. A Phoenix design dropped into Houston without re-engineering will create humidity problems.
Link →Plumbing
Plumbing terms
- Grease Interceptor
- An in-ground or in-line unit that separates fats, oils, and grease (FOG) from kitchen wastewater before it enters the sewer. Sizing follows the adopted plumbing code — rated flow for hydromechanical units, drainage fixture units for gravity interceptors under the UPC — plus the sewer utility’s FOG rules.
- Fats, Oils, and Grease· FOG
- The grease a kitchen sends to its interceptor; wok and fryer-heavy menus send more than a sauté line.
- Floor Drain
- A floor-level drain typically required under hood, sink, and ice-machine areas. The plumbing code sets a 2-inch minimum outlet; high-flow areas often get 3-inch.
- Indirect Waste
- A drain that discharges to a floor sink with an air gap (not a direct connection to the sewer). Required for ice machines, food-prep sinks, and most refrigeration condensate lines.
Why it matters: Under-sized interceptors back up and draw sewer-utility enforcement; replacing one after the slab is poured is costly.
Link →Why it matters: FOG rules are local: the sewer utility’s FOG program sets interceptor review and pump-out frequency — ask early.
Link →Why it matters: If the existing slab does not have drains in the right spots, saw-cutting concrete to add them typically runs $3K–$8K per drain, plus permit time.
Link →Why it matters: Inherited spaces often have direct-waste connections that need to be re-plumbed before health-department sign-off.
Link →Electrical
Electrical terms
- Three-Phase Power· 3-phase
- A 208V or 480V power service that delivers three alternating-current phases — required for most large commercial equipment (mixers, batch freezers, induction tables, large dish machines).
- Amperage
- The current draw of a circuit, measured in amperes (A). A 3-group espresso machine pulls 30–40A at 208V; a pressure fryer pulls 30–50A.
- Sub-Panel
- A secondary electrical panel fed from the main service, used to localize circuits in a specific zone (kitchen, basement, rooftop).
Why it matters: Many smaller retail shells have single-phase 120/240V service. Upgrading to 3-phase typically runs $5K–$25K for transformer and service work, depending on utility coordination.
Link →Why it matters: Inherited 20A receptacles cannot serve most commercial cook-line equipment. New dedicated circuits and panel capacity are mandatory line items.
Link →Why it matters: High-amperage kitchens often need a dedicated sub-panel; expect roughly $4K–$9K including conduit, wire, and labor.
Link →Code
Code terms
- Authority Having Jurisdiction· AHJ
- The local government body that issues building permits and enforces code in a specific jurisdiction — typically the city building department; the fire marshal and health department are AHJs for their parts.
- International Building Code· IBC
- The model commercial building code published by the International Code Council and adopted, with local amendments, across the U.S. ICC issues a new edition every three years; your project follows the edition your city or state has adopted.
- International Residential Code· IRC
- The model residential code (one- and two-family dwellings and townhouses). Applies to custom homes and most ADUs; not to commercial restaurant TI.
- International Energy Conservation Code· IECC
- The model energy code governing building envelope, HVAC efficiency, lighting power density, and commissioning. ICC issues a new edition every three years; your project follows the edition your city or state has adopted.
- NFPA 96
- NFPA’s Standard for Ventilation Control and Fire Protection of Commercial Cooking Operations — the national standard behind most hood, grease-duct and kitchen fire-suppression rules.
- International Plumbing Code· IPC
- The model plumbing code. Section 1003 sets grease-interceptor sizing; Section 802 covers indirect waste; others set drain sizing by drainage fixture units, and venting.
- Americans with Disabilities Act· ADA
- Federal civil-rights law requiring accessible design in public accommodations; its design rules are the 2010 ADA Standards. Building departments separately enforce accessibility through IBC Chapter 11 / ICC A117.1 (California: CBC Chapter 11B).
- Occupancy Classification
- The IBC category that controls a building’s required egress, sprinkler load, fire separation, and bathroom count. Restaurants and bars are Group A-2 (Assembly); a dining space with fewer than 50 occupants is classified as Group B (Business).
- Occupant Load
- The IBC-prescribed maximum number of people permitted in a space. Calculated by dividing floor area by the factor in IBC Table 1004.5 — 15 net sq ft per person at tables and chairs, 7 for chairs only, 5 for standing space.
Why it matters: Two restaurants 8 miles apart can have wildly different plan-check rhythms and code interpretations because they sit under different AHJs.
Link →Why it matters: Restaurant TI plan review is anchored in the IBC plus the local amendments — know both before drafting.
Link →Why it matters: Live/work or attached-restaurant projects sometimes straddle IBC + IRC; pulling the right code path early avoids late-stage re-engineering.
Link →Why it matters: Restaurants are energy-intensive; IECC compliance on hood schedules, MUA, and lighting routinely surprises operators coming from older shells.
Link →Why it matters: Depending on the city, it applies directly, through the fire code, or through the mechanical code, which carries closely matching rules for clearances, duct construction and access panels.
Link →Why it matters: Interceptor rules come from your city’s plumbing code — IPC §1003, or UPC §1014 where a UPC-based code applies, as in California — plus the sewer utility’s FOG program. Check both before you bid the lease.
Link →Why it matters: California adds its own accessibility chapter (CBC 11B), checked in plan review on top of the ADA. At dining surfaces at least 5% of seating and standing spaces must be accessible (2010 ADA Standards 226.1).
Link →Why it matters: Reaching 50 occupants flips a small café from B to A-2 — different plumbing-fixture math and other A-2 rules. The threshold is binary.
Link →Why it matters: Occupant load drives bathroom count, exit-door width, and emergency-lighting math. 2,000 sq ft of table seating is about 133 occupants — well past the 50-person A-2 line; standing room counts higher.
Link →Process
Process terms
- Plan Check
- The AHJ's formal review of a submitted permit set against code. Reviewers issue corrections; the design team responds; the cycle repeats until the set clears.
- Permit-Ready Set
- A complete architectural drawing set sufficient for plan-check submission — code analysis, site, floor plan, RCP, elevations, schedules, MEP coordination notes.
- Code Memo
- A pre-drafting deliverable identifying applicable codes, occupant load, IBC section analysis, and flagged compliance risks BEFORE any sheets are drawn.
- Request for Information· RFI
- A formal question from the contractor or AHJ during construction asking the designer to clarify intent, dimension, or specification of the drawings.
- Certificate of Occupancy· CO
- The final AHJ document permitting the building to be occupied — issued after final inspection passes building, electrical, plumbing, mechanical, and fire-marshal sign-offs.
Why it matters: Anticipating plan check before submission saves correction cycles. Building departments publish their own review targets — Phoenix, for example, posts its goals monthly.
Link →Why it matters: Not the same as a construction set. Permit-ready clears AHJ review; CD-level adds the granular detail GCs need to build from. APD's default deliverable is permit-ready.
Link →Why it matters: A code memo before drafting catches deal-breaker issues (occupancy crossover, hood clearance) while there's still time to renegotiate the lease.
Link →Why it matters: Tracked, dated, and resolved cleanly, an RFI log keeps a project moving. Sloppy logs are how 2-week delays become 2-month delays.
Link →Why it matters: No CO = no opening day. Plan time at the end for the final building, fire, and health sign-offs.
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