What is included in a complete MEP plan set for an ADU?

A permit-ready California ADU MEP set is a coordinated package of cover, mechanical, electrical, and plumbing sheets — complete with calculations, schedules, and the code notes a plan reviewer expects to find. It is not a single drawing but a small bound set, typically six to ten sheets depending on project complexity. Here is what each part contains.

Cover sheet

Project address, scope of work, the applicable code editions (CBC, CEC, CPC, CMC, plus Title 24 and CALGreen references), a sheet index, deferred-submittal notes if any, and the general notes that apply across the set.

Mechanical sheets (M-1, M-2)

• HVAC system type and layout with equipment locations
• Manual J heat-load calculation sized to your climate zone
• Equipment schedule with make, model, and efficiency ratings (SEER2 / HSPF2)
• Whole-dwelling ventilation per ASHRAE 62.2 and Title 24
• Ducting (if applicable), kitchen exhaust, bathroom fans, and condensate drainage

Electrical sheets (E-1, E-2)

• Electrical floor plan with all outlets, switches, lighting, and fixtures
• Panel schedule listing every circuit, plus a service or feeder load calculation
• Dedicated circuits for HVAC, range, washer/dryer, water heater, and EV charger where applicable
• GFCI and AFCI notation, smoke/CO alarm locations, and solar-ready conduit if required

Plumbing sheets (P-1, P-2)

• Plumbing floor plan with all fixture locations
• Fixture schedule with make, model, and flow rates
• Water-supply design and the complete DWV (drain, waste, vent) system
• Sewer connection details, water-heater specs, backflow prevention, and gas piping if applicable
• CALGreen low-flow fixture compliance

A reviewer's quick checklist

If you want to sanity-check a set before submitting, confirm it answers each of these without a phone call:

1. Which code editions was it designed to? (cover sheet)
2. Is every piece of equipment listed with a model number? (schedules)
3. Does a load calculation justify the panel? (electrical)
4. Does the ventilation rate meet ASHRAE 62.2? (mechanical)
5. Is the DWV properly vented with cleanouts shown? (plumbing)

When all five are present and the sheets agree with the architectural set, the package is permit-ready — the level of completeness we deliver, not preliminary sketches.

How the sheets are organized

The set follows a logical reading order that mirrors how a plan reviewer works through it. The cover sheet establishes scope and code; the mechanical, electrical, and plumbing sheets each open with a plan view, then back it up with the schedules, calculations, and notes that prove the design complies. General notes and legends explain the symbols, while detail callouts handle anything that needs to be drawn at a larger scale — a panel detail, a vent termination, or a condensate routing, for example. Because the disciplines are coordinated, an item that appears in two places — the water heater on plumbing and its circuit on electrical — is shown consistently in both.

What is intentionally not included

An MEP set does not contain architectural floor-plan dimensions, structural framing, or Title 24 energy modeling — those are separate deliverables that live on their own sheets. Understanding this boundary helps you assemble a complete permit package: architectural, structural (if required), MEP, and the Title 24 report together form the full submittal. We focus on the MEP portion and coordinate it to the architectural set you provide.

The closely related Title 24 report

Title 24 energy compliance (the CF1R report) is a separate but tightly linked document. Bundling it ensures the equipment efficiencies on your mechanical sheets match the energy model, which removes one of the most common sources of plan-check corrections. See Title 24 Reports, the Full MEP Package, and the Complete ADU MEP Guide. Exact sheet content can vary by jurisdiction, so confirm local checklist items with your building department.