24 CFR § 3280.115 - Sound transmission between multi-dwelling unit manufactured homes.

---
identifier: "/us/cfr/t24/s3280.115"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "24 CFR § 3280.115 - Sound transmission between multi-dwelling unit manufactured homes."
title_number: 24
title_name: "Housing and Urban Development"
section_number: "3280.115"
section_name: "Sound transmission between multi-dwelling unit manufactured homes."
chapter_name: "OFFICE OF ASSISTANT SECRETARY FOR HOUSING—FEDERAL HOUSING COMMISSIONER, DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT"
part_number: "3280"
part_name: "MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "15 U.S.C. 2697, 42 U.S.C. 3535(d), 5403, and 5424."
regulatory_source: "40 FR 58752, Dec. 18, 1975, unless otherwise noted. Redesignated at 44 FR 20679, Apr. 6, 1979."
cfr_part: "3280"
---


# 3280.115 Sound transmission between multi-dwelling unit manufactured homes.

(a) *Scope.* This section applies to common interior walls, partitions, and floor/ceiling assemblies between adjacent dwelling units.

(b) *Air-borne sound.* Walls, partitions, and floor/ceiling assemblies between stories separating dwelling units from each other must have a sound transmission class (STC) of not less than 34 for air-borne noise when tested in accordance with ASTM E90 (incorporated by reference, see § 3280.4) or calculated. Penetrations or openings in construction assemblies for piping; electrical devices; recessed cabinets; bathtubs; soffits; or heating, ventilating, or exhaust ducts must be sealed, lined, insulated or otherwise treated to maintain the required ratings. This requirement does not apply to dwelling unit entrance doors; however, such doors must be tight fitting to the frame and sill.

(c) *Structure-borne sound.* Floor/ceiling assemblies between stories separating dwelling units must have an impact insulation class (IIC) rating of not less than 34 when tested in accordance with ASTM E492 (incorporated by reference, see § 3280.4).

[89 FR 75745, Sept. 16, 2024]