Noise in new-build apartments: does your home meet the updated acoustic standards?

Buying a new-build apartment is often an investment in comfort and peace. Yet noise from footsteps upstairs, conversations through walls or ventilation equipment can seriously affect daily life. Updated acoustic standards have applied in Belgium since 2023. What should you expect from a new home?

Updated acoustic standard since 2023

In Belgium, NBN S 01-400-1:2022 is the main technical reference for acoustic performance in residential buildings. It replaced the 2008 edition and serves as a code of good practice for residential buildings whose planning-permit application was submitted after 1 January 2023.

The updated standard addresses several types of sound transmission:

• Airborne noise: conversations, music and television from neighbouring apartments.
• Impact noise: footsteps, moving chairs and dropped objects.
• Building-services noise: ventilation, lifts, heat pumps and garage doors.
• Façade sound insulation: protection from traffic and other external noise.
• Reverberation: troublesome sound reflections in certain shared spaces.

The standard assesses the finished building. Choosing suitable materials alone is not enough: workmanship and connections between building elements also determine performance.

What does European legislation say?

Noise protection is also addressed at European level.

The new EU Construction Products Regulation (EU) 2024/3110, generally applicable since 7 January 2026, includes fundamental requirements for construction works, including protection against noise.

Annex I highlights the need to design and construct buildings so occupants are sufficiently protected from sound transmission and can sleep, rest and carry out everyday activities under normal conditions.

However, EU legislation does not impose one uniform set of minimum sound-insulation values for all homes across the Union. Specific performance levels are determined nationally.

In Belgium, NBN S 01-400-1:2022 is the principal technical reference.

Important: the EU Construction Products Regulation does not automatically make the Belgian acoustic standard legally mandatory. The standard is primarily a recognised code of good practice and may also be contractually binding.

Three acoustic comfort levels

The updated Belgian standard distinguishes three performance classes:

Class	Acoustic comfort
A	Highest level of acoustic protection
B	Enhanced acoustic comfort
C	Basic acoustic protection

Class C generally serves as the minimum reference level for new homes. Stricter requirements may apply where a higher level of comfort was agreed.

Compliance does not mean that an apartment is completely soundproof. Some sounds may still be audible even in a properly constructed building.

Why do acoustic problems still occur in new buildings?

Building inspections regularly reveal shortcomings that reduce sound insulation. The issue often lies not in the specified materials but in their installation.

1. Acoustic bridges in floors

Floating screeds are commonly used to reduce impact noise between apartments. The screed is acoustically separated from the structural slab and adjacent walls.

If perimeter insulation is missing or damaged, or if the screed touches other structural elements, acoustic bridges can form. Vibrations then travel more readily to neighbouring homes.

Even local installation defects can undermine the performance of an entire floor assembly.

2. Sound transmission through walls and services

Sound does not travel only through separating walls. It can also pass through floors, ceilings, façades and service shafts. This is known as flanking transmission.

Poorly sealed pipe penetrations, defective junctions or insufficient isolation can allow conversations and other sounds to be heard between apartments.

3. Noise from technical installations

Ventilation systems, lifts, heat pumps and automatic garage doors are frequent sources of disturbance.

The cause may be excessive sound from the equipment itself or vibrations transmitted through its fixings and the building structure.

Equipment can operate correctly in technical terms while still failing to meet the applicable acoustic criteria. Such noise can be particularly disruptive in bedrooms.

How can you check whether your apartment meets the standard?

People perceive noise differently, which is why objective assessment matters.

Specialist acoustic measurements can determine whether insulation between apartments or noise from technical installations meets the applicable criteria.

Depending on the complaint, testing may include:

• Airborne sound insulation: measuring transmission between two rooms.
• Impact sound insulation: testing with a standardised tapping machine.
• Building-services noise: measuring ventilation, lifts or garage doors.
• Façade sound insulation: assessing protection against external noise.

Results are assessed against the applicable acoustic standard and prescribed measurement methods, including the NBN EN ISO 16283 series.

Audible noise does not automatically establish a construction defect. Conversely, a building element that seems satisfactory may perform inadequately when measured.

Is the acoustic standard legally mandatory?

An NBN standard is not automatically legislation. The Belgian acoustic standard is primarily an important reference for accepted good building practice.

If expressly included in the specifications or sales agreement, it may also be contractually binding.

Even without such a clause, it may be relevant when assessing workmanship and construction quality.

The applicable edition and requirements depend on factors such as the permit-application date, the type of work and contractual agreements. Renovations may also be subject to particular constraints and possible derogations.

What if your new apartment has inadequate sound insulation?

If you experience noise nuisance, the first step is to establish its cause.

Insufficient acoustic performance may result from a design error, inappropriate materials or defective workmanship.

Possible remedies range from improving junctions and isolating equipment against vibration to substantial changes to floor or wall assemblies.

It is therefore advisable to carry out objective measurements first and then investigate the underlying cause of any shortcomings.

In new-build apartments, this deserves particular attention at provisional and final handover. Acoustic problems often become apparent only once neighbouring apartments are occupied.

Conclusion: good sound insulation takes more than good materials

The updated Belgian standard NBN S 01-400-1:2022 provides an important framework for assessing residential acoustic comfort.

Although European legislation also addresses protection against noise, the specific acoustic performance criteria for Belgian homes are principally determined by the national standard.

In practice, workmanship is often decisive. A small acoustic bridge or poorly executed junction can significantly reduce sound insulation.

Experiencing noise in a new-build apartment? Specialist acoustic testing can clarify the building's actual performance.

HEXA Experts assists owners and co-owners' associations in investigating building defects and works with specialist partners for acoustic measurements.

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Sources

• NBN S 01-400-1:2022 – Acoustic criteria for residential buildings.
• Regulation (EU) 2024/3110 – EU Construction Products Regulation, Annex I, point 5.
• Buildwise – Belgian acoustic standards and guidance on the updated criteria.
• NBN EN ISO 16283 – Field measurement methods for sound insulation in buildings.

This article is based on legislation and technical standards as understood in October 2026. Applicability must be assessed for each building and project.