The furnish / install / connect matrix: how MEP scope gaps get caught before they become change orders
Every experienced PM has a story that starts with "I thought you had it." The fire/smoke damper actuators that need 120V and nobody carried the circuits. The line-voltage thermostats that shipped loose in a box on the unit heater and sat in the conex until punch. The housekeeping pads that were in the concrete bid and the mechanical bid. None of these are big items. All of them show up as change orders, schedule delays, or money left on the table. A scope responsibility matrix is how you find them on paper instead of in the field.
What a responsibility matrix is (and what it isn't)
A responsibility matrix — also called a division of responsibility (DOR), an F-I-C matrix, or an MEP coordination matrix — is a one-page grid. Items go down the side, parties go across the top, and every cell says what that party does for that item: furnish, install, connect, or nothing. It's not a scope of work or a subcontract exhibit by itself. It's the cross-reference that makes sure the scopes you did write add up to 100% of the job with nothing counted twice.
The template above is pre-loaded with 28 of the most common interface items on a commercial building — the Div 23 / Div 26 / Div 28 split that causes the most trouble — plus the owner, GC, plumbing, controls, and low-voltage columns you'll need on nearly every job.
F, I, C — the three verbs that matter
| Code | Means | Typical example |
|---|---|---|
| F | Furnish — buys it, delivers it to site | Mechanical furnishes the VFDs specified in Div 23 |
| I | Install — receives, sets, mounts, supports | Mechanical installs duct smoke detector housings in the duct |
| C | Connect — final power, control, or piping termination | Electrical connects power to the rooftop unit disconnect |
| F-I | Furnish and install | Plumbing furnishes and installs the water heater |
| I-C | Install and connect | Electrical mounts the VFD and wires line and load |
| F-C | Furnish and connect (someone else installs) | Fire alarm furnishes and wires the duct smoke detector; mechanical mounts it |
| F-I-C | The whole thing | Electrical furnishes, installs, and wires the equipment disconnects |
| — | Explicitly not in this party's scope | Use it to show you looked and decided |
The Div 23 / Div 26 / Div 28 items that cause the most trouble
These are the lines pre-seeded in the matrix, with the split you'll see on most commercial jobs. Your specs may say otherwise — the point is to read them and write the answer down.
Motor control and power
- VFDs — commonly furnished by Div 23 (they're specified with the equipment), installed and wired line/load by Div 26, and connected for start/stop, speed reference, and BACnet by controls. Three parties, one device — it has to be on the matrix.
- Motor starters — factory-mounted starters come with packaged equipment (Mechanical F-I, Electrical C). Loose starters and MCC buckets are usually Div 26 F-I-C. Check coil voltage and auxiliary contacts needed by controls.
- Disconnect switches — usually Div 26, unless the equipment schedule calls for unit-mounted disconnects. Look at the mechanical schedule's "disconnect by" column if there is one. For motor full-load current and disconnect sizing references, see our motor FLC chart.
- Line-voltage thermostats on unit heaters — shipped loose by Div 23, installed and wired by Div 26. Classic "it was in the box" item.
- Condensate pumps — often missing from the electrical drawings entirely. The template flags this one as an example gap.
Controls / BAS
- Control wiring — low-voltage sensors, actuators, and relays by the controls contractor (Div 23 09 xx).
- 120V to BAS panels — typically electrical brings a dedicated circuit to a junction box; controls makes the final connection. Get panel locations early or you'll be relocating circuits.
- Thermostats and space sensors — controls furnishes, installs, and wires the device; electrical often provides back boxes and conduit stubs. Two rows, two responsible parties.
Fire alarm and life-safety interfaces
- Duct smoke detectors — fire alarm furnishes and wires; mechanical mounts the housing and sampling tubes in the duct. Whether one is required on a given unit depends on airflow thresholds in the mechanical code — verify against the edition adopted by your AHJ.
- Fire/smoke dampers — the damper is mechanical. The 120V actuator power is the single most common gap on commercial jobs: Div 23 says "power by Div 26," and Div 26 shows nothing. The template seeds it as a GAP so you can see what the check looks like.
- Flow and tamper switches, elevator recall and shunt trip, door hold-opens — each touches fire alarm plus another trade. Put every one on its own row.
Pads, supports, and owner equipment
- Housekeeping pads — frequently carried by the concrete sub and the mechanical sub. The template shows it as an example OVERLAP. One of them gets a deduct.
- OFCI equipment (owner-furnished, contractor-installed) — decide who receives, unloads, stores, sets, and connects, and who owns the warranty if it's damaged on site.
How the gap / overlap check works
For each row the sheet counts how many parties have an F, an I, and a C:
- No installer or no furnisher → GAP. Nobody is carrying it.
- Two installers or two furnishers → OVERLAP. Someone is getting paid twice, or you're carrying it twice in your number.
- Connection required = Y and no C → GAP – no connection. The equipment gets set and never gets wired.
- Two connectors is allowed — power and control connections are normally split. If you want to be precise, split the row ("VFD — line/load power" and "VFD — control & BACnet").
A summary block at the top counts OK, gaps, and overlaps, and tells you when the matrix is clean. A row under the table counts how many items each party has — a quick sanity check when you hand a trade its column.
When to build it: bid, buyout, precon
- At bid. Estimators on both sides of the line read each other's spec sections. Every gap you find is either an RFI (see the pre-bid RFI log) or a clear qualification in your proposal.
- At buyout. The GC attaches the matrix to each subcontract as a scope exhibit, and uses it to level sub bids — an item one sub excluded is a plug in the bid leveling matrix.
- At precon. Walk the matrix line by line with every MEP and fire alarm foreman in the room. Have each party sign. Re-issue with a revision date when anything changes.
Common mistakes
- Listing every item on the job. The matrix is for interfaces. If a single trade furnishes, installs, and connects it with no one else involved, it doesn't need a row.
- Leaving cells blank instead of using "—". A blank cell means nobody looked. A dash means somebody decided.
- Treating it as the contract. The matrix interprets the documents; it doesn't replace them. When the specs conflict, get an addendum or RFI answer and then update the matrix.
- Building it once. Change orders, value engineering, and substitutions change who does what. Update it and re-issue.
From spreadsheet to project record
The matrix finds the gaps; something still has to track them to closure. Field PM keeps RFIs and change orders, submittals, and subcontract scope in one project record, so the gap you find on the matrix becomes a tracked RFI — and if it turns into a change, the cost lands on the right budget line. Start a free 30-day trial — no credit card required.
Related free templates
- Bid Leveling Matrix — plug the scope a bidder excluded and compare leveled totals
- Pre-Bid Site Visit Checklist & RFI Log — turn gaps into pre-bid questions
- Supplier RFQ Template — send the same material request to every supplier
- RFI Template — document the question and the answer
- Submittal Log — track the equipment on the matrix through approval
- Browse all free construction templates
