Apartment Unit Remodel Title 24 Requirements
Remodeling one apartment triggers Title 24 only for the components you alter under Section 180.2: replaced windows, opened walls and floors, new lighting, new ducts or equipment, replaced fans. Components you leave alone carry no new requirement. Any altered measure that needs ECC verification is tested in that unit alone, never in a sample group.
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What the unit scope pulls in
- Opened walls and floors: an altered wood-framed wall facing outdoors or unconditioned space reaches R-11 between framing or U-0.110, and a raised framed floor R-11 or U-0.071.
- Lighting: altered dwelling-unit lighting meets Section 160.5(a). Existing screw-base sockets in recessed housings may stay if JA8 trim kits or lamps go in.
- Ducts: more than 25 feet of new or replacement duct brings sealing and insulation rules. Replacing an air handler, condensing unit or coil triggers sealing to 15 percent leakage, or 10 percent to outside, unless the duct run is under 40 linear feet or was previously verified.
- Fans: a replacement whole-dwelling fan must be supply, balanced or the existing type. Where an earlier permit required a kitchen hood or exhaust fan, the replacement must move at least that airflow or 100 cfm, whichever is greater. No unit air leakage test applies to alterations.
How verification works in an occupied building
Reference Appendix RA2.8 is blunt: when an alteration needs field verification, the dwelling unit is verified individually, and altered units may not join a sample group. The building department does not approve the alteration until it holds the certificate of installation and the certificate of verification. Where nothing needs field verification, Section 10-103(a)1C lets the department skip the certificates or use a simplified form at its discretion, though the work must still comply.
Choosing a path
The component rules of Section 180.2(b) are the prescriptive path. An existing-plus-alteration model under Section 180.2(c) is the alternative when one prescriptive item is hard to meet. A renovation that touches many units multiplies the testing, so ask the ECC-Rater how many visits to schedule.
Window details are on apartment window replacement, ducts and equipment on multifamily HVAC, and heaters on water heater replacement. The building-wide view is on multifamily remodels, and reports start at the multi-family service.
Common Title 24 Questions
- Do apartments need Title 24?
- Does a duplex need Title 24?
- Do triplexes and fourplexes need Title 24?
- Which Title 24 forms does a multi-family project use?
- What is an LMCC certificate?
- How much does a multi-family Title 24 report cost?
Frequently Asked Questions
No. Reference Appendix RA2.8 requires field verification of an alteration for the dwelling unit individually and bars altered units from a designated sample group.
Only if the work alters regulated components such as lighting, fans, windows, ducts or equipment. Components left alone carry no new requirement, and the building department decides the permit scope.
Explore Multi-Family
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- Does a Duplex Need Title 24?
- What Is Dwelling Unit Compartmentalization?
- Fourplex Title 24 Requirements
- What Is an LMCC Certificate?
View all Multi-Family guides → · Permits and Compliance · Title 24 guide