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Don’t get screwed.</text><text x="58" y="258" font-family="Arial,Helvetica,sans-serif" font-size="30" font-weight="600" fill="#6b5b4d">Leases, TI, NNN &amp; buildouts — negotiated in your favor</text><g transform="translate(1010,86)" fill="none" stroke="#C0531F" stroke-width="9" stroke-linejoin="round"><rect x="20" y="40" width="150" height="130"/><line x1="20" y1="40" x2="95" y2="6"/><line x1="170" y1="40" x2="95" y2="6"/><rect x="50" y="80" width="36" height="36"/><rect x="104" y="80" width="36" height="36"/><rect x="74" y="128" width="42" height="42"/></g></svg>

Do I Need a Grease Interceptor, and What Does It Cost?

Direct Answer

If you cook, fry, or even run a three-compartment sink in a food business, you almost certainly need a grease interceptor, and the price swings wildly: $250 to $1,500 for a small under-sink hydromechanical grease interceptor (HGI), installed for $1,500 to $5,000 — versus $5,000 to $40,000+ for a buried exterior gravity grease interceptor (GGI) of 750 to 2,000 gallons, where the excavation, concrete, and plumbing dwarf the tank itself.

The money-move: find out which one your local plumbing authority demands before you sign the lease, because the buried version can cost more than your entire kitchen equipment package and is the most common reason a restaurant buildout blows its budget.

The trigger is rarely your choice. It is set by your local sewer authority or health department, usually based on your number of seats, the size of your kitchen, your fixture count, or a flow calculation in gallons per minute. Many jurisdictions follow the Uniform Plumbing Code (UPC) or International Plumbing Code (IPC) sizing tables, but the local utility can — and often does — override them with stricter rules.

A coffee shop with a single prep sink might pass with a $400 under-sink unit. A full-service restaurant with a hood, fryers, and 80 seats will almost always be forced into a 1,000-gallon-plus exterior interceptor, which means trenching, possibly cutting the parking lot, and tying into the sewer — easily $15,000 to $40,000.

Here is the trap that ends deals: many older retail spaces and strip malls have no grease interceptor at all and no place to put one. If there is no exterior dirt to dig into, or the sewer connection is on the far side of a shared lot, the cost can balloon past $50,000 or become physically impossible.

Confirm feasibility, not just code, before you commit a dollar.

Two Kinds of Interceptor, Two Very Different Bills

Hydromechanical grease interceptors (HGIs) — also called grease traps — sit under the sink or in the floor near the kitchen. They are small, 20 to 100 gallons of capacity rated in GPM and pounds of grease, and they are cheap. Unit cost $250 to $1,500; installed $1,500 to $5,000 if the drain line is accessible.

The catch: they need cleaning every 1 to 4 weeks, and a city inspector or a pumping log will check.

Gravity grease interceptors (GGIs) are the large buried concrete or fiberglass tanks, 750 to 3,000 gallons, that sit outside in the ground. The tank itself is $1,500 to $8,000, but the install is the whole story:

• Excavation and backfill: $3,000 to $10,000.
• Concrete cutting and asphalt patch if you have to go through a slab or parking lot: $2,000 to $8,000.
• Plumbing tie-in and venting: $3,000 to $10,000.
• Permits, engineering, and inspection: $1,000 to $5,000.

Add it up and a typical full-service restaurant GGI lands at $15,000 to $40,000, with extreme sites past $50,000. Pumping a GGI runs $150 to $500 per visit, every 1 to 3 months.

How the Size Gets Decided (and How to Argue It Down)

The number is calculated, not pulled from the air, which means it can be challenged. Common methods:

• Fixture-unit / drainage method. The plumbing inspector totals the drainage fixture units (DFU) of your sinks, dishwasher, and floor drains and reads a required GPM off a table.
• Seat-count method. Some health departments size by seats × a meal-factor × hours, then add safety multipliers.
• Flat municipal mandate. Plenty of cities simply require a minimum 1,000- or 1,500-gallon GGI for any commercial kitchen, full stop.

The lever: a licensed plumbing engineer who knows the local table can sometimes keep you in a smaller unit by not over-counting fixtures — for example, routing only the grease-bearing fixtures (prep sinks, wok stations, dishwasher pre-rinse) to the interceptor and keeping hand sinks and restrooms on the sanitary line.

Every fixture you legitimately keep off the grease line lowers the required size. Have the engineer present the calculation; do not let the contractor default to the biggest tank "to be safe," because that safety costs you tens of thousands.

Shift It to the Landlord So You Don't Get Screwed

This is the difference between a profitable deal and an underwater one.

• Make grease infrastructure a delivery condition. If the space is being leased as a restaurant or food use, negotiate that the landlord delivers an existing, adequately sized grease interceptor or funds its installation. In second-generation restaurant spaces, an interceptor often already exists — confirm its size and condition.
• Use the tenant improvement allowance. A buried interceptor is a permanent improvement to the landlord's property that outlasts your tenancy. That is exactly the kind of capital item a TIA of $30 to $100+ per square foot should cover. Frame it that way: "This is your building's asset, not my equipment."
• Get a feasibility contingency in the LOI. Make the lease contingent on confirming, within 30 to 45 days, that a compliant interceptor can be installed at a defined maximum cost. If the site cannot physically take one, you walk with your deposit.
• Pin down who maintains and replaces it. Pumping and cleaning is usually the tenant's operating cost, but repair or replacement of a failed tank should sit with the landlord as a structural/building-system item. Spell it out.
• Beware the "as-is" trap. An "as-is" delivery on a raw space means you eat the entire interceptor cost. Push for grease infrastructure to be explicitly carved out of "as-is."

The leverage: a buried interceptor permanently increases the building's value as a food-capable space. A landlord who wants a restaurant tenant has every reason to fund the asset that makes the space rentable to the next restaurant too.

Keeping the Ongoing Cost Sane

The interceptor is not a one-time line item. Plan the operating cost so it does not bleed you:

• Right-size the cleaning frequency. An undersized HGI cleaned weekly costs more in service calls than a properly sized one cleaned monthly. Size for your real volume.
• Keep a pumping log. Cities issue fines for missed cleanings, and a fat enough HGI failure can clog the sewer and trigger a fats, oils, and grease (FOG) violation with penalties in the $1,000 to $10,000 range.
• Negotiate a service contract, not per-call pricing. A scheduled GGI pumping contract runs cheaper per visit than emergency calls and keeps you out of violation.

FAQ

Do I need a grease interceptor for a coffee shop or a space with just a prep sink? Often a small under-sink HGI is enough, sometimes none at all, depending on whether you produce FOG. Confirm with the local sewer authority — a barista pulling shots is very different from a kitchen with a fryer, and the rule is set locally, not by guesswork.

Why is the buried gravity interceptor so much more expensive than the under-sink one? The tank is the cheap part. The cost is the excavation, concrete or asphalt cutting, sewer tie-in, venting, engineering, and permits — frequently $15,000 to $40,000 combined, versus $1,500 to $5,000 for an under-sink unit where the drain is already accessible.

Can I make the landlord pay for it? Frequently, yes. A buried interceptor is a permanent building improvement that benefits the landlord's asset, so it is a strong candidate for the tenant improvement allowance or an outright landlord-delivered condition. Negotiate it before signing — afterward you have no leverage.

What happens if I skip it or undersize it? You fail your health and plumbing inspection and cannot open. If you somehow open and grease clogs the sewer, you face FOG violation fines, emergency cleanup bills, and potential shutdown. It is not a corner you can cut.

Sources

• CBRE — Restaurant and retail tenant fit-out cost benchmarking.
• JLL — Food-and-beverage buildout cost guides and delivery-condition briefings.
• Cushman & Wakefield — Tenant representation on restaurant lease delivery and TIA negotiation.
• RSMeans (Gordian) — Grease interceptor, excavation, and sewer tie-in unit cost data.
• ICC / International Plumbing Code (IPC) — grease interceptor sizing requirements.
• IAPMO / Uniform Plumbing Code (UPC) — hydromechanical and gravity interceptor sizing tables.
• EPA / local FOG (fats, oils, grease) program guidance and pretreatment requirements.
• NAIOP — capital improvement allocation between landlord and tenant in commercial leases.