Mechanical, electrical and plumbing (MEP) estimating is hard for a simple reason: three trades share the same ceiling space, the same equipment and the same schedule. Each trade’s own estimate can be done well while the combined MEP number is still wrong. Most often that happens because a piece of scope falls between them or gets counted twice.
This guide shows how the three trades fit together, what drives cost in each, and how to build a combined MEP estimate that a general contractor or owner can review line by line.
How MEP Maps to MasterFormat
| Trade | Division | Typical contents |
|---|---|---|
| Fire suppression | 21 – Fire Suppression | Sprinklers, standpipes, fire pumps |
| Plumbing | 22 – Plumbing | Domestic water, sanitary and storm, fixtures, water heaters, medical gas |
| HVAC | 23 – HVAC | Ductwork, equipment, hydronic and refrigerant piping, controls, test-and-balance |
| Electrical | 26 – Electrical | Service, distribution, branch power, lighting, generators |
| Communications | 27 – Communications | Data and voice cabling, pathways |
| Safety and security | 28 – Electronic Safety and Security | Fire alarm, access control, video surveillance |
Each trade follows its own codes: the NEC (NFPA 70) for electrical, the IPC or UPC for plumbing, the IMC for mechanical, NFPA 13 for sprinklers, and ASHRAE 62.1 and 90.1 (or the local energy code) for ventilation and energy. Before you start, confirm which editions the jurisdiction has adopted.
What Drives Cost in Each Trade
Mechanical (Division 23)
- Ductwork is measured by size and converted to weight by gauge. See our HVAC estimating guide for the conversion.
- Equipment (RTUs, AHUs, chillers, boilers, VRF) is priced from dated vendor quotes, including freight, rigging and startup.
- Piping (hydronic, steam, refrigerant, condensate) is taken off by material, size and joining method.
- Air devices and terminal units are counted from schedules.
- Controls and test-and-balance are often separate subcontracts, so confirm their scope in writing.
Electrical (Division 26)
- Distribution: switchgear, panelboards and transformers from quotes, checked against the one-line diagram.
- Feeders and branch circuits: conduit and wire, including vertical runs and makeup. Check conduit fill (NEC Chapter 9: 40% for more than two conductors). See the electrical estimating guide.
- Lighting and controls: counts by fixture type, reconciled with the fixture schedule.
- Equipment connections: one for every mechanical and plumbing item that needs power.
Plumbing (Division 22)
- Piping by system: domestic water, sanitary, vent, storm, gas. Keep below-grade and above-grade separate.
- Fixtures with carriers, trim and ADA accessories.
- Equipment: water heaters, pumps, interceptors, backflow preventers.
- Specialty systems such as medical gas (NFPA 99). See the plumbing estimating guide.
The Scope Responsibility Matrix
The most useful single document in an MEP estimate is a responsibility matrix. It lists every item that crosses trade lines and says who furnishes it, who installs it, and who wires or connects it. Specifications usually cover this in Division 23 and 26 coordination sections, but drawings and specs don’t always agree.
| Item | Furnish | Install | Power wiring | Control wiring |
|---|---|---|---|---|
| Rooftop units | Mechanical | Mechanical | Electrical | Controls |
| VAV boxes | Mechanical | Mechanical | Electrical (if fan-powered or electric reheat) | Controls |
| Motor starters / VFDs | Confirm in specs | Confirm in specs | Electrical | Controls |
| Fire/smoke dampers | Mechanical | Mechanical | Electrical | Fire alarm / controls |
| Water heaters | Plumbing | Plumbing | Electrical | — |
| Condensate drains | Confirm | Mechanical or plumbing | — | — |
| Duct smoke detectors | Fire alarm | Mechanical (in duct) | Fire alarm | Fire alarm |
Fill in this table for each project from the actual documents. The entries above show common arrangements, not rules. Anything that stays unclear should become an RFI or a clearly stated inclusion or exclusion.
Labor: Base Units, Adjustments and Burden
Each MEP trade usually starts from published or software-based labor units, such as NECA units for electrical or MCAA units for mechanical and plumbing, and calibrates them with job-cost history. Then the estimator applies project-specific factors. Common factors include:
- Working height and lift requirements
- Ceiling congestion and coordination density
- Occupied-building or phased renovation work
- Prefabrication, which moves hours from the field to the shop
- Schedule compression and overtime
Worked Example: Multi-Trade Labor Roll-Up
Example (not a real project; illustrative 2026 rates. Use your own burdened rates and local wage data): A tenant fit-out has high open ceilings, so an adjustment factor applies to the overhead work.
| Trade | Base hours | Adjustment factor | Adjusted hours | Burdened rate (illustrative) | Labor cost |
|---|---|---|---|---|---|
| Plumbing | 140 | 1.05 | 147 | $92/hr | $13,524 |
| HVAC | 220 | 1.10 | 242 | $90/hr | $21,780 |
| Electrical | 260 | 1.10 | 286 | $88/hr | $25,168 |
| Total | 620 | 675 | $60,472 |
Checks:
- Plumbing: 140 x 1.05 = 147, and 147 x $92 = $13,524
- HVAC: 220 x 1.10 = 242, and 242 x $90 = $21,780
- Electrical: 260 x 1.10 = 286, and 286 x $88 = $25,168
- Hours: 147 + 242 + 286 = 675. Cost: $13,524 + $21,780 + $25,168 = $60,472
The adjustment adds 55 hours (675 - 620) across the three trades. Showing it as a separate factor, instead of building it into the base units, lets a reviewer see it and argue with it. Burdened rates should be built from local wages plus payroll taxes, insurance and fringes.
Software and Takeoff Tools
Takeoff is commonly done in general-purpose tools such as Bluebeam Revu or PlanSwift. Pricing is done in trade-specific estimating platforms that carry assemblies, material databases and labor units for electrical and mechanical work. Whatever tools you use, the output should be a quantity list organized by CSI section and system, so it can be checked and leveled against subcontractor bids.
MEP Estimating Checklist
- Confirm adopted code editions for each trade
- Build the responsibility matrix before pricing
- Reconcile every equipment schedule with the plans and specifications
- Create an equipment connection list for electrical from the mechanical and plumbing schedules
- Keep below-grade plumbing, overhead work and rooftop work as separate line items
- Record vendor quote dates, lead times and exclusions
- Apply labor adjustments as visible factors
- Include controls, test-and-balance, commissioning support and closeout documents
- Check Division 21, 27 and 28 scope so nothing is dropped or double-counted
- List inclusions, exclusions and assumptions in the proposal
Common Mistakes
- Estimating each trade in isolation without a shared responsibility matrix.
- Missing equipment connections and control wiring between Divisions 23 and 26.
- Relying on rules of thumb where vendor quotes are needed.
- Burying labor factors so reviewers can’t see or question them.
- Letting fire alarm, controls or low-voltage cabling fall between packages.
- Ignoring coordination density in tight ceiling spaces.
A clearly organized quantity list also makes it much easier to level MEP subcontractor bids against each other.
How F&K Estimatings Can Help
F&K Estimatings prepares MEP takeoffs across Divisions 22, 23 and 26, organized by CSI MasterFormat and system, with scope gaps between trades flagged as RFIs. Waqas Malik reviews scopes for commercial MEP packages. See our MEP estimating services, review pricing, or contact us with your drawings.