Documento Básico HR (DB-HR) – Spanish Noise Protection Building Code
The Documento Básico HR (DB-HR Protección frente al ruido) is a mandatory technical regulation issued by the Ministerio de Transportes, Movilidad y Agenda Urbana of Spain. This document forms part of the Código Técnico de la Edificación (CTE), the national legal framework governing building standards. This consolidated version, dated December 20, 2019, incorporates amendments from several legislative acts, including Real Decreto 1371/2007 and Real Decreto 732/2019.
The regulatory scope of the DB-HR is defined by Article 14 of the CTE Part I, which establishes the basic requirements for protection against noise. It applies to new constructions and specific renovation projects across various building categories, including residential, hospital, educational, and administrative uses. The document provides objective parameters and verification systems to limit risks to health and comfort caused by airborne noise, impact noise, and vibrations from building installations. It also sets limits for reverberation in specific internal spaces.
The following sections detail the technical thresholds, scope exclusions, and the two available verification methods—the Opción simplificada and the Opción general—as prescribed within the consolidated regulatory text.
Scope and Field of Application
The DB-HR applies generally to all buildings regulated by the CTE, with specific exceptions for high-noise environments and specific historical preservation cases. Regulated spaces are classified as either `recintos protegidos` (protected rooms like bedrooms or classrooms) or `recintos habitables` (habitable rooms like kitchens or bathrooms).
- Exclusions: Noisy rooms (recintos ruidosos) governed by specific regulations, and performance venues such as theaters or cinemas which require bespoke acoustic studies.
- Historical Buildings: Excluded when compliance would unacceptably alter the facade or protected interior distribution of officially cataloged heritage sites.
- Volume Thresholds: Classrooms and conference halls with a volume exceeding 350 m³ are subject to special acoustic design studies rather than standard DB-HR tables.
Acoustic Insulation Limit Values
The document defines mandatory minimum insulation levels for airborne noise and maximum levels for impact noise. These values vary depending on the relationship between the noise-emitting and the noise-receiving spaces.
- Airborne Noise (DnT,A): Must not be less than 50 dBA between protected rooms and other units of use, or less than 55 dBA when the adjacent room is a machine room (recinto de instalaciones) or an activity room (recinto de actividad).
- Internal Partitions (RA): Vertical partitions within the same unit of use must have a global acoustic reduction index (índice global de reducción acústica) of at least 33 dBA.
- Impact Noise (L’nT,w): The standardized impact sound pressure level in protected rooms must not exceed 65 dB for vertical or horizontal adjacencies with different units of use.
Reverberation and Absorption Limits
Limits for reverberation time are established for empty spaces to ensure speech intelligibility and acoustic comfort in public-use areas.
- Classrooms and Conference Rooms: For volumes under 350 m³, the reverberation time (tiempo de reverberación) must not exceed 0.7 seconds when empty.
- Restaurants and Dining Halls: The limit is set at 0.9 seconds for empty spaces.
- Common Areas: In residential, hospital, or educational buildings, common areas adjacent to protected rooms must have an equivalent absorption area (área de absorción acústica equivalente) of at least 0.2 m² per cubic meter of volume.
Verification Procedures
The DB-HR offers two paths for compliance verification, allowing designers to choose between prescriptive solutions or performance-based calculations.
- Opción simplificada: Uses predefined tables and specific construction solutions (Type 1, Type 2, and Type 3 partitions) to meet minimum requirements without complex modeling.
- Opción general: Based on calculation models from the UNE-EN ISO 12354 standards, estimating acoustic performance based on the specific properties of construction elements and their joints (encuentros).
Frequently Asked Questions
What is the minimum airborne noise insulation required between different apartments?
According to Section 2.1.1, the standardized airborne noise insulation (DnT,A) between a protected room and another unit of use must be at least 50 dBA.
What is the maximum allowed impact noise level in a bedroom?
The standardized impact sound pressure level (L’nT,w) in a protected room generated by adjacent units of use must not exceed 65 dB.
Does DB-HR apply to the renovation of protected historical buildings?
Renovations of officially protected buildings are excluded if compliance would negatively impact the facade or internal configuration required for historical conservation.
What is the limit for reverberation time in an empty classroom?
For classrooms with a volume of less than 350 m³, the reverberation time must be no higher than 0.7 seconds.
What are the requirements for internal partitions within the same dwelling?
Internal partitions (tabiquería) within a single private residential unit of use must have a global acoustic reduction index (RA) of at least 33 dBA.
How is impact noise addressed in machine rooms?
Impact noise from machine rooms (recintos de instalaciones) received in protected rooms must not exceed a standardized level (L’nT,w) of 60 dB.
