How a Multifamily Title 24 Report Is Built
A multifamily Title 24 report models the building as a whole and each dwelling unit within it. Every unit has its own floor area, windows, orientation and equipment, and each one has to be accounted for before the building can show compliance.
For low-rise multifamily buildings the compliance document is usually the LMCC. The building type and how the code classifies it decide which form applies, and the report uses the correct one. If you are unsure which one your project needs, CF1R vs LMCC explains the difference.
Duplex, Triplex and Fourplex: What Changes Per Unit
Two units that look identical on paper can perform differently in the energy model. The items that change unit by unit include:
- Orientation and window area. A unit with large west-facing glass carries a higher cooling load than its mirror image facing east.
- Position in the building. End units have more exterior wall than middle units, and upper units sit under the roof while lower units sit on the slab or raised floor.
- Shared assemblies. Walls and floor/ceilings between units separate conditioned spaces and are modeled differently from exterior walls.
- Equipment. Each unit's heating, cooling, ventilation and water heating are entered separately unless a central system serves several units.
Duplex Title 24
A duplex is the simplest multifamily model: two units, usually side by side or stacked. Side-by-side units each have their own roof and floor, while stacked units split them, so the lower unit models the floor and the upper unit models the roof. A duplex report is covered by the base multifamily price.
Triplex Title 24
With three units, at least one unit usually sits between two others or under another unit, so its exposure is quite different from the end units. A triplex often mixes unit sizes as well, and each unit's floor area and window layout are modeled individually.
Fourplex Title 24
Fourplexes are often two-over-two or four side-by-side units. Both layouts have a mix of end, middle, upper and lower positions, which is where per-unit modeling matters most. A fourplex up to 4,000 sq ft is included in the base price.
Common Multifamily Compliance Items
Beyond the per-unit envelope, multifamily reports often address:
- Water heating layout. An individual water heater in each unit and a central system serving several units are modeled differently, and a central system adds distribution requirements.
- Ventilation. Each dwelling unit needs its own ventilation, and it is often a HERS/ECC field verification item.
- HERS verification per unit. Items such as duct leakage, refrigerant charge, airflow and fan efficacy are flagged on the compliance document for the rater to verify after installation. See HERS rater vs Title 24 report.
- Solar, battery and electric-ready measures. These depend on the project type, scope and code cycle, and the report determines which apply.
- Common areas. Shared corridors, laundry rooms and exterior lighting can bring their own requirements.
The climate zone for the address also changes the energy budget for every unit; find yours on the California climate zones map. For a code-level overview, see Title 24 requirements, and for how the whole-building model is compared with the code's standard design, see Title 24 calculations.
Documents to Send for a Multifamily Report
- Floor plans for every unit, with unit numbers and conditioned floor areas
- Exterior elevations showing all windows and doors
- Sections or assembly notes for exterior walls, roof, floors and walls between units
- A window schedule and a site plan with a north arrow and project address
- HVAC and water heating equipment for each unit, or the central system design
Our guide to what documents to upload has more detail.
Per-Building Pricing and Turnaround
Multifamily reports are priced per building, based on square footage and unit count:
| Item | Detail |
|---|---|
| Base price per building | $345, includes up to 4,000 sq ft and 4 units |
| Additional area | +$25 per 500 sq ft over 4,000 sq ft |
| Additional units | +$95 per unit beyond 4 |
| Standard turnaround | 2–3 business days after complete plans |
| 24-hour rush | +$149 |
| Super Rush (same day) | +$150, typically within a few hours; contact us for urgent projects |
For example, a six-unit building of 5,000 sq ft would be $345 + $50 for the extra area + $190 for the two extra units, or $585. If a lot has two separate buildings, each is priced on its own. The final price follows the plans, and we contact you before proceeding if it needs adjusting. For tight permit deadlines, see rush and same-day service.
You receive a permit-ready PDF by email, prepared in CEC-approved software and registered with CHEERS where the project requires it. Two revisions are included for design changes or plan check comments.
More Multifamily Title 24 Questions
Do identical units need to be modeled separately?
Each unit is entered in the model, because orientation and position in the building change the result even when the floor plans match. Repeated unit plans make the work simpler, but they are still modeled individually.
Does each building on the lot need its own report?
Separate buildings are normally documented and priced separately, since each has its own envelope and systems. Tell us how many buildings are on the plans when you order.
What about mixed-use buildings with commercial space?
Nonresidential space follows a different compliance path. Request a custom quote through our commercial quote form.
