What is the relationship between MEP plans and Title 24?

Title 24 sets the energy-efficiency rules; the MEP plans must reflect them. The Title 24 compliance report — the CF1R for residential work — establishes the minimum efficiency requirements your ADU has to meet, and the mechanical, electrical, and plumbing drawings have to specify equipment that satisfies those minimums. When the two documents don't agree, the plans get corrected. They are separate deliverables, but they are joined at the hip.

What Title 24 dictates on your MEP sheets

• HVAC efficiency — minimum SEER2/HSPF2 (or equivalent) ratings for the heating and cooling equipment shown on the mechanical sheets
• Water-heating efficiency — the type and efficiency standard for the water heater on the plumbing sheets
• Lighting power density — limits and high-efficacy lighting requirements reflected on the electrical sheets
• Ventilation — mechanical ventilation rates coordinated with ASHRAE 62.2 and the energy model

Two ways to comply

Title 24 offers a prescriptive path (meet a fixed checklist of measures) and a performance path (model the whole building and trade measures against one another). The path chosen changes which equipment values land on your MEP sheets. An experienced provider picks the approach that matches your design and climate zone, then carries those exact values into the drawings so the two never diverge.

Why coordination prevents corrections

Mismatched equipment is one of the most common sources of plan-check comments. For example, if the CF1R models a heat pump at a given efficiency but the mechanical schedule lists a unit that falls short, the reviewer issues a correction and the plans go back for revision — costing you a review cycle.

When the same team prepares both the CF1R and the MEP plans, the equipment efficiencies are matched from the start — the energy model and the mechanical schedule simply agree — which eliminates one of the most frequent reasons ADU permits get kicked back.

Climate zone drives the numbers

California's 16 climate zones each carry different Title 24 requirements, so the efficiency targets — and therefore the equipment on your MEP sheets — depend on where the ADU is built. An air-source heat pump that sails through compliance on the coast may need a different specification inland. This is also a key reason MEP plans can't be reused across properties in different zones.

Is Title 24 always required for an ADU?

For new conditioned living space — which describes nearly every ADU — California requires Title 24 energy compliance documentation as part of the permit package. The CF1R demonstrates that the building envelope, HVAC, water heating, and lighting meet the current energy standards. Because the report directly constrains the equipment on your MEP sheets, it is best treated as part of the same effort rather than an afterthought handed to a different consultant. The trend toward all-electric, heat-pump-based ADUs is largely driven by these same Title 24 standards, which increasingly favor high-efficiency electric equipment.

We offer the Title 24 energy report as a +$240 add-on precisely so it can be prepared alongside your MEP set and stay coordinated. See Title 24 Reports and the bundled Full MEP Package for details. As always, confirm jurisdiction-specific energy requirements with your local building department.