The CTE-HR standard requires 50 dB DnT,A between dwellings. Across the 254 acoustic projects we delivered in 2025 we systematically measure the in-situ result — these are the 3 errors that bring that figure down on site, even when the system's datasheet promises more.
Noise is one of the most frequent and most difficult problems to solve in dwellings in the Balearic Islands. From the constant traffic on the main avenues of Maó to the night-time activity of tourist areas, including the neighbours on the floor above, noise pollution affects the quality of life of thousands of residents in Menorca.
The regulation that governs the acoustic insulation of buildings in Spain is the Basic Document HR (Protection against Noise) of the Technical Building Code, known as CTE-HR. This regulation establishes the minimum insulation levels that dwellings must meet, and is the legal framework that every owner, developer or installer should be aware of before addressing any noise-related work.
In this guide we explain what the CTE-HR requires, how it applies in the Balearic Islands, what differences exist between old and new buildings, and how plasterboard systems make it possible to meet and exceed these requirements. If you need a direct solution, consult our page on acoustic insulation in Menorca.
What is the CTE-HR?
The Technical Building Code (CTE) is the regulatory framework that establishes the basic quality requirements that buildings in Spain must meet. Within this code, the Basic Document HR (DB-HR) is specifically dedicated to protection against noise.
The CTE-HR came into force in October 2007 and represented a radical change compared to the previous regulation (NBE-CA-88), which dated from 1988 and which, in practice, allowed very poor acoustic insulation levels. Before 2007, many buildings were constructed with party walls of single hollow brick that barely reached 35-40 dB of insulation, when the minimum that allows reasonable coexistence is at least 50 dB.
Objectives of the CTE-HR
The DB-HR pursues three fundamental objectives. The first is to limit the transmission of airborne noise between rooms (conversations, music, television). The second, to limit the transmission of impact noise through the slabs (footsteps, falling objects). And the third, to limit the noise of building installations (lifts, pipes, air conditioning systems).
For each of these objectives, the CTE-HR establishes minimum numerical values that must be verified through in situ tests or predictive calculations based on the construction solutions used.
Key difference: laboratory values vs in situ values
A point that frequently generates confusion is the difference between insulation measured in a laboratory (R or Rw) and insulation measured in situ (DnT,A). The laboratory value is obtained under ideal conditions, without lateral transmissions or execution defects. The in situ value reflects the reality of the finished work, where noise can be transmitted through the side walls, the slab, the socket boxes or any acoustic bridge.
The CTE-HR requires in situ values, which means that the construction solution must be correctly executed to achieve the values planned in the project. A system that offers 55 dB in a laboratory can drop to 45-48 dB in situ if the installation has defects.
Minimum CTE-HR Values: Table 2.1
Table 2.1 of the DB-HR establishes the airborne sound insulation values (DnT,A) between rooms. These are the values that directly affect dwellings:
CTE-HR, Table 2.1 — Minimum airborne sound insulation values (DnT,A) between rooms:
- Separation between a unit of use and any other habitable room: DnT,A ≥ 50 dB
- Separation between a unit of use and a facilities room: DnT,A ≥ 55 dB
- Separation between a unit of use and an activity room (commercial premises, bar, restaurant): DnT,A ≥ 55 dB
Translated into practical language: the wall between your flat and your neighbour's must insulate at least 50 dB of airborne noise. If your flat is above or next to a bar, a supermarket or a gym, the separation must insulate at least 55 dB.
Values for impact noise
For impact noise (footsteps, knocks), the CTE-HR uses the parameter L'nT,w and establishes that the normalised impact sound pressure level in a protected room (bedroom, living room) must not exceed L'nT,w ≤ 65 dB. This value refers to the noise transmitted through the slab, and the lower the value, the better the insulation.
Values for facilities noise
The building's facilities (lift, pressure group, boiler, pipes) must not generate noise levels in the protected rooms above LAeq ≤ 30 dBA for continuous noise (such as a boiler) and LAmax ≤ 33 dBA for intermittent noise (such as a lift or a cistern).
Specific Regulations in the Balearic Islands
In addition to the CTE-HR, which is at state level, the Balearic Islands have autonomous and municipal regulations that complement the acoustic insulation requirements.
Law 1/2007 against Acoustic Pollution of the Balearic Islands
This autonomous law establishes the general framework for protection against noise in the Balearic Islands. It defines acoustic zones, acoustic quality objectives on the exterior of buildings and the obligation to draw up strategic noise maps for municipalities with more than 100,000 inhabitants (Maó).
The law classifies the areas of the territory according to their predominant use (residential, commercial, industrial, tourist) and establishes maximum ambient noise levels for each. For example, in a residential area, the limit is 55 dBA during the day and 45 dBA at night. In a tourist area, the limits are similar but night-time leisure activities generate frequent breaches.
Maó municipal noise ordinance
Maó has a municipal ordinance for protection against noise that specifically regulates the activity of hospitality venues, discos, concert halls and any activity likely to generate noise disturbance to neighbours.
This ordinance is particularly relevant in districts such as Historic Centre, Sant Climent, Old Quarter and the Historic Centre, where the concentration of leisure venues is high. The ordinance requires the owners of these venues to ensure that their activity does not exceed the established noise emission limits, which often forces them to install additional acoustic insulation.
Other municipalities with their own ordinances
Ciutadella, Alaior, Sant Lluís and Es Mercadal also have municipal noise ordinances, adapted to the particularities of each municipality. In areas with high tourist concentration such as Cala Santandria (Ciutadella) or the Port of Sant Lluís, these ordinances may establish stricter requirements than the state regulations for night-time leisure venues.
Old Buildings vs New Buildings in Menorca
The problem of pre-2007 buildings
The CTE-HR came into force in October 2007. All buildings constructed before that date are governed by the previous regulation (NBE-CA-88 or, in many cases, no specific acoustic regulation). The Menorcan housing stock has a very high proportion of pre-2007 buildings:
In buildings from the 1950s-60s, with load-bearing walls and joist slabs without any acoustic criterion, insulation between dwellings barely reached 35-40 dB. During the real estate boom of the 1960s-80s, single hollow brick party walls (4-5 cm) and joist and vault slabs without absorbent material offered between 38 and 43 dB. From the 1980s to 2007, the improvement was partial with double hollow brick party walls (7-9 cm) or perforated brick and, in some buildings, an air cavity, reaching 42-47 dB.
In all these cases, insulation is below the 50 dB minimum required by the CTE-HR. In a 1970s building in Maó, it is common to clearly hear the neighbour's conversations, television at normal volume or footsteps from the upper floor. We explain how to solve these problems in our guide on acoustic insulation in old buildings in Maó.
New buildings must comply
Buildings with a works licence after October 2007 are obliged to comply with the CTE-HR. This implies that party walls, slabs and facades must reach the specified minimum values. In practice, many developers in Menorca have adopted plasterboard systems for interior divisions precisely because they make it possible to reach these values with more ease and less weight than traditional masonry solutions.
Renovations: a middle ground
In partial renovations (changing the layout of a dwelling, rehabilitating a room), it is not compulsory to reach the CTE-HR values, unless the renovation affects elements of separation between different units of use. However, there are two compelling reasons to use them as a reference. The first is technical: the CTE-HR values represent the minimum for reasonable acoustic coexistence. The second is economic: if you are going to invest in insulation, it makes sense to do it right in one go.
How Plasterboard Systems Comply with the CTE-HR
Plasterboard systems offer a fundamental technical advantage over traditional masonry for compliance with the CTE-HR: they make it possible to create multi-layer partitions with absorbent materials and decoupled structure, which is the most effective acoustic principle.
Mass-spring-mass principle
The acoustic performance of a plasterboard system is based on the mass-spring-mass principle. The plasterboards act as masses and the mineral wool in the cavity acts as an absorbent spring. This system is more acoustically efficient than a simple mass of the same weight (such as a brick wall), because the discontinuity between the layers hinders the transmission of vibration.
A plasterboard partition with double board on each side and high-density mineral wool weighs about 50-60 kg/m² and reaches 55-60 dB of airborne sound insulation. A perforated brick wall of 11.5 cm weighs 150-180 kg/m² and reaches 45-48 dB. Plasterboard achieves more insulation with three times less weight.
Solutions by level of requirement
To meet DnT,A ≥ 50 dB (separation between dwellings): A self-supporting wall lining with 70 mm structure, high-density mineral wool (60 kg/m³) of 60 mm and double board of 12.5 mm. This system, attached to an existing brick wall, typically reaches 50-53 dB in situ. Indicative cost: €10-€15/m² over the existing wall.
To meet DnT,A ≥ 55 dB (dwelling-commercial premises separation): Wall lining with double independent structure (no contact with each other), high-density mineral wool of 80 mm and double board with viscoelastic sheet. This system reaches 55-60 dB in situ. Indicative cost: €15-€22/m².
To meet L'nT,w ≤ 65 dB (impact noise): False ceiling with anti-vibration suspension (silent blocks), mineral wool of 80 mm and double board. In combination with the existing slab, this system allows compliance with the impact limit in most cases. If the slab is very light, it may be necessary to complement with a floating floor on the upper floor. Anti-vibration false ceiling cost: €15-€20/m².
To learn in detail about the types of installation available, consult our page on plasterboard installation in Menorca.
The importance of construction detail
The CTE-HR is not met just by choosing the right system; execution is decisive. The critical points that determine actual performance are:
Anti-vibration bands are essential: the metal structure must never be in direct contact with the existing walls, floor or ceiling, and EPDM or polyethylene bands must be placed at all points of contact. Sealing of perimeter joints is also critical, as the joint between the wall lining and the floor, ceiling and side walls must be sealed with flexible acoustic sealant. Regarding socket boxes and mechanisms, a poorly sealed socket in a plasterboard wall can reduce insulation by 5-8 dB, so acoustic mechanism boxes should be used or sealed with intumescent sealant. Finally, facility passages require attention: any pipe or cable that crosses the acoustic wall must be sealed with elastic materials.
Case Study: 1975 Building in the Ensanche of Maó
To illustrate how the CTE-HR is applied in practice, this is a real case of a project we carried out in a residential building in the Ensanche of Maó.
Initial situation
The building, constructed in 1975, has single hollow brick party walls of 4 cm with plaster rendering on both sides. The insulation measured between the two dwellings was 38 dBA, well below the 50 dB required by the CTE-HR. The owners of the flat could clearly hear the conversations, television and telephone of their neighbours.
The slab between floors is of prestressed joist and ceramic vault, without absorbent material. The impact noise level measured was 78 dB, far exceeding the 65 dB limit of the CTE-HR.
Solution executed
On the party walls, a decoupled self-supporting wall lining was installed, with a 70 mm structure separated 10 mm from the existing wall using EPDM anti-vibration bands, high-density mineral wool (60 kg/m³) of 60 mm and double board of 12.5 mm with staggered joints. Socket boxes were specially treated with recessed acoustic boxes and sealing sealant.
On the ceiling of the living room and bedrooms, a false ceiling was installed with anti-vibration suspension (Sylomer silent blocks), mineral wool of 80 mm and double board of 12.5 mm. The light fittings were integrated without perforating the acoustic barrier, using sealed boxes.
Results
After the intervention, the acoustic measurements certified the following values:
The airborne sound insulation on the party walls went up to 52 dBA (before: 38 dBA), an improvement of 14 dB that complies with the CTE-HR (≥ 50 dB). The impact noise level in the bedrooms was reduced to 62 dB (before: 78 dB), an improvement of 16 dB that also complies with the CTE-HR (≤ 65 dB).
The owners stopped hearing the neighbours' conversations completely. Footstep noise went from being clearly audible and annoying to being a barely perceptible background sound.
Investment
The total cost of the intervention was €7,800 for an 85 m² flat (wall lining of two party walls of 28 m² total + acoustic false ceiling in living room and two bedrooms of 42 m² total). VAT not included. The execution period was 6 working days.
What we see on our projects
The first error we find most often is poorly resolved lateral transmission: noise doesn't only cross the party wall we treat, it also flanks in through the façade and the slab. A textbook case in 1970s Maó buildings: an impeccable acoustic wall lining on the party wall, but façade and slab left untouched. We measure and the real insulation sits 4-6 dB below projected. The usual fix is extending the lining 50-60 cm onto the side walls or treating the flanking element directly.
The second error is blind boxes, sockets and recessed boxes left unsealed. It looks minor and is decisive: one socket connecting the lining cavity with the exterior strips around 5-8 dB from the whole system. Blind boxes are even worse because they are large openings with a direct path to street or courtyard. The fix is recessed acoustic back-boxes, flexible acoustic sealant and specific treatment of the blind-box housing.
The third error is the missing perimeter decoupling band: the wall lining or false ceiling rests directly on slab and side walls with no elastic band between them. That creates a rigid bridge letting noise through by structural vibration. With properly placed EPDM or polyethylene bands at every contact point we typically recover 5-8 dB. What to demand from the installer, in one line, is that they include in the quote and actually build: a decoupled lining with perimeter band on all three contacts (floor, ceiling, side walls), acoustic back-boxes on every pass-through mechanism and a full perimeter seal with acoustic mastic. Without that, the in-situ measurement will not match the datasheet.
Verification of Compliance: In Situ Acoustic Tests
To verify that a work complies with the requirements of the CTE-HR, in situ acoustic tests can be carried out according to the UNE-EN ISO 16283 standards (for airborne and impact noise). These tests are carried out by accredited laboratories and consist of generating controlled noise in one room and measuring the noise level transmitted to the adjoining room.
When are the tests compulsory?
In new-build buildings, the CTE requires that the project includes a justification of compliance with the DB-HR through predictive calculations. In situ tests are not generally compulsory, but they are when the control authority so requires or when there is a complaint for non-compliance.
In practice, in Menorca, acoustic tests are frequently carried out in these cases: new buildings with more than 10 dwellings (sampling), hotels and tourist apartments with activity licence, hospitality venues with neighbour complaints, and judicial complaints between neighbours for noise.
Cost of the tests
An in situ acoustic test in Menorca has a cost of €300 to €600 per measurement point. For a typical dwelling 2-4 points are needed (a party wall, a slab, the facade), which represents an investment of €600 to €2,000 including the technical report.
Practical Recommendations for Owners in Menorca
If you live in a pre-2007 building and suffer from noise problems, these are the practical recommendations based on our experience:
Identify the main noise transmission path. Before spending a euro, determine whether the noise enters through the wall, the ceiling, the floor or the windows. Insulating the party wall will not do much if the main noise enters through the slab. A prior technical evaluation is essential.
Prioritise decoupled solutions. A wall lining glued to the existing wall offers an improvement of 3-5 dB. A decoupled wall lining with anti-vibration bands offers 10-15 dB of improvement. The cost difference is only €3-€5/m², but the performance difference is enormous.
Do not skimp on high-density mineral wool. The density of the wool is the most determining factor of its acoustic performance. A 60 kg/m³ wool absorbs significantly more noise than a 20 kg/m³ one, especially at medium and low frequencies. The price difference between the two is €2-€4/m², but the performance is 30-40% higher. To see the detailed costs of each system, consult our soundproofing prices guide in Menorca.
Demand the installation of anti-vibration bands and acoustic sealing. If your installer does not use anti-vibration bands at all points of contact of the metal structure and does not seal the perimeter joints, the system's performance will be significantly reduced. These details make the difference between reaching 45 dB or 52 dB with the same system.
Consider integral intervention. If noise is transmitted through several paths (wall + ceiling + sockets), insulating only the wall will give a partial result. Noise always finds the easiest path, and when one route is blocked, it is redistributed through the others. Consult with your installer for an integral solution that addresses all transmission paths.
Next Step
If you need to evaluate the level of acoustic insulation of your dwelling in Menorca or want a solution that complies with the CTE-HR, our technical team carries out free in situ evaluations. We analyse the noise transmission paths, propose the most suitable technical solution and deliver a fixed quote.
Consult our acoustic insulation services in Menorca or request your free evaluation. You can also call us directly on 627 829 723.
