How to demonstrate compliance with DB-HR: a practical guide for building projects
The acoustic comfort of a building depends on more than just how well its walls insulate against external noise. Sound transmission between rooms, impact noise, building services and the way sound behaves within each space also play a role. For this reason, acoustics should be considered from the earliest stages of a project rather than treated as a last-minute fix.
The Basic Document DB-HR, Protection Against Noise, of the Spanish Technical Building Code sets out the requirements that must be considered to limit noise-related disturbances and risks in buildings within its scope. Demonstrating compliance involves defining appropriate construction solutions, verifying their performance and documenting that the proposed building meets the applicable requirements.
In this guide, we provide a general overview of how to demonstrate compliance and the role acoustic treatment plays in the overall quality of interior spaces.
What is DB-HR and what does it aim to achieve?
DB-HR is the Basic Document of the Spanish Technical Building Code dedicated to protection against noise. Its purpose is to establish the rules and procedures for meeting the basic acoustic protection requirements.
These requirements cover different aspects of a building’s acoustic performance:
- Protection against airborne noise from outside or from other rooms.
- Limiting the transmission of impact noise.
- Controlling noise and vibrations generated by building services.
- Limiting reverberation in certain spaces.
- Reducing noise transmission between rooms through appropriate construction solutions.
Not all buildings or rooms are subject to the same requirements. The application of DB-HR depends on the building’s use, the type of construction work, its characteristics and the conditions established by the regulations.
How to demonstrate compliance with DB-HR?
The compliance assessment must form part of the technical design documentation and be consistent with the solutions that will ultimately be implemented. Although each building requires a specific assessment, the process can be broken down into several stages.
1. Identify the scope of application and the different types of rooms
The first step is to determine which requirements apply to the project. To do this, the technical team must analyse the building’s intended use, the rooms and spaces it contains, and how they relate to one another.
It is important to identify, among others, protected rooms, habitable rooms, activity rooms, plant rooms and any spaces that may have special acoustic requirements. This classification determines the applicable sound insulation requirements and, where relevant, acoustic treatment requirements.
The specific circumstances of existing buildings, renovations and changes of use must also be considered, as the regulatory requirements may differ from those applicable to new construction.
2. Define the applicable acoustic requirements
Once the spaces have been identified, the requirements that must be met are established: airborne sound insulation, impact noise insulation, noise from building services and reverberation control, as applicable.
At this stage, it is important to distinguish between the parameters used to characterise individual products and those that describe the acoustic performance of the completed building.
Laboratory test results for a building element do not automatically reflect the sound insulation achieved between two rooms, as installation quality, junctions between building elements and indirect sound transmission also influence the final performance.
3. Select and size the construction solutions
The project must specify the building elements needed to achieve the required acoustic performance: façades, partitions, floor slabs, floating floors, ceilings, doors, windows and building services systems, among others.
DB-HR provides compliance assessment procedures, including the simplified method and the general method, whose applicability depends on the specific conditions of the project. The responsible technical team must select the appropriate procedure.
Where required, calculations must account not only for direct sound transmission but also for indirect transmission through building elements and their junctions.
4\. Incorporate acoustic treatment where necessary
Sound insulation and acoustic treatment address different issues, although both form part of a comprehensive acoustic strategy.
The purpose of sound insulation is to limit sound transmission between spaces or from outside. Acoustic treatment, on the other hand, focuses on how sound behaves within a room, controlling reverberation and reflections to improve the acoustic conditions for its intended use.
In spaces where DB-HR establishes requirements relating to reverberation, the project must demonstrate compliance through the appropriate solutions and assessment procedures.
In other spaces, even where DB-HR does not specify a reverberation time requirement, incorporating acoustic treatment may be advisable for functional reasons, occupant comfort or architectural quality.
5. Document acoustic performance and installation
The compliance assessment must be supported by the technical documentation for the selected systems and clearly defined installation requirements.
Depending on the project, this may require calculations, technical data sheets, test results, construction details, material specifications and construction quality control documentation. Proper installation is particularly important, as even a well-designed solution can lose acoustic performance due to sound bridges, poorly sealed joints or deviations from the original specifications.
Where applicable, on-site measurements can be used to verify the acoustic performance of the completed building in accordance with the relevant procedures.
The importance of acoustic treatment for compliance and building quality
Acoustic treatment plays a specific role within DB-HR, but its value goes beyond simply meeting regulatory limits.
In classrooms, conference rooms, restaurants, offices, auditoriums and public buildings, controlling reverberation can help improve speech intelligibility, reduce the build-up of sound energy and create environments better suited to their intended activities.
The aim is not to achieve the highest possible level of sound absorption, but to distribute and size acoustic surfaces in a balanced way, while also considering sound reflections that may be beneficial.
Common mistakes when demonstrating acoustic compliance
One of the most common mistakes is leaving acoustics until the final stages, when finishes and building services have already been specified. At that point, the options for making changes may be more limited, and the solutions more complex.
Another common mistake is confusing laboratory test results with actual on-site performance, using sound absorption data from a configuration different from the one specified, or assuming that meeting sound insulation requirements automatically guarantees indoor acoustic comfort.
The best way to avoid these problems is to coordinate the architectural team, acoustic engineers, manufacturers and installers from the outset, establishing clear objectives and verifying that the specified solutions are compatible with the project.
How Decustik can help with an acoustic treatment project
At Decustik, we specialise in manufacturing acoustic and decorative panels for interior architecture. Since 1982, we have been developing solutions for walls and suspended ceilings, working alongside architects, interior designers, engineers and installers on projects that combine technical performance with design.
Our role is to support the selection and manufacture of sound-absorbing systems suited to the requirements established in each acoustic design.
If you are working on a building project and need to include acoustic panels in the technical specifications, reverberation calculations or interior finish specifications, our team can help you select from the available configurations and provide the technical documentation needed to specify the products.
