HN 33:2026 – what changed in Lithuania's noise hygiene norm

HN 33:2026 noise limit values

HN 33:2026 (full title: "Noise limit values in residential and public buildings and their environment") was approved by Order No. V-131 of the Lithuanian Minister of Health of 10 February 2026 and applies from 13 February 2026. It sets limit values for noise from stationary sources and transport in residential and public buildings and outside them.

Table 1. Indoor noise limits (equivalent sound pressure level L_AeqT, dBA)

Table 2. Outdoor noise limits at facades of residential and public buildings, children's playgrounds and sports grounds, and quiet recreation areas for elderly and disabled people (dBA)

Day, evening and night periods are as defined in the Lithuanian Law on Noise Management. Outdoor noise at facades is measured or modelled under free-field conditions. Noise from building services is measured according to EN ISO 16032; wind turbine noise is calculated according to ISO 9613-2:2024. Where impulsive or tonal sounds are identified, the assessment and corrections of ISO 1996-1 and ISO 1996-2 must be applied (point 14 of the norm). Source: HN 33:2026, consolidated version (in Lithuanian).

Lithuania's new hygiene norm HN 33:2026 brought one of the biggest changes in noise regulation in recent years – the maximum sound pressure level limit values were abolished. For some this is a long-awaited reform, for others a potential gap in the protection of residents. The question is whether all the consequences of this decision were properly assessed when the new hygiene norm was drafted.

What changed in HN 33:2026?

The new hygiene norm introduced several fundamental changes to how noise studies are carried out:

• maximum sound pressure level limit values L_AFmax were removed;
• transport noise is assessed using the long-term indicators L_D, L_V, L_N and L_DVN;
• noise is no longer assessed at site boundaries.

Removing maximum levels for road traffic – a logical decision

For road traffic, this change appears justified.

Until now, assessing the maximum sound level caused many practical problems. A single passing truck or motorcycle could exceed the limit value even though the overall background noise was not high. Because of such isolated events, expensive noise barriers or other measures sometimes had to be designed that brought no tangible benefit to residents.

The decision to assess road traffic noise using the equivalent sound level is therefore understandable and helps avoid unnecessary bureaucratic procedures.

Railway noise should be tackled at the source

Maximum sound level limits were also removed for railway transport. This means that short but very intense sounds – wheel impacts, brake squeal in stations or wagon couplings – are no longer assessed against a maximum sound pressure level limit.

In the long term, railway noise should not be reduced by noise barriers alone. In the view of Vytautas Lapinskas, director of UAB Tyrimų laboratorija, a much more effective approach would be to reduce noise at the source – for example, using sound-absorbing and insulating materials close to the rolling stock. The technical condition of trains also affects noise levels.

The biggest risk – industrial noise

The greatest concern is that maximum sound level limits have also been removed for industrial noise.

Many factories, warehouses, logistics centres and other industrial facilities generate impulsive rather than steady noise: metal impacts, container handling, the thumping of production equipment, presses or loading operations.

If only the equivalent sound level is assessed, short but very loud impulses can "dissolve" in the daily average and formally not breach the hygiene norm.

This can also have economic consequences. Residential areas near industrial sites become less attractive and property values may fall, even though official noise measurements show no exceedance. In such cases the only way to establish the real situation objectively is professional acoustic measurements that separate short, intense sound peaks from the overall background noise.

Why standard noise measurements alone are not enough

Noise measurement methods provide for corrections to the equivalent sound level of up to 12 dB when impulsive or clearly pronounced impact noise is identified. Such corrections allow the real effect of noise on people to be assessed more accurately. The methods require it to be identified whether impulsive sounds were present.

In practice in Lithuania, however, these corrections are applied very rarely. When the older hygiene norm still contained a maximum noise requirement, applying impulsive noise corrections made little difference – but now it is the only indicator protecting against impulsive noise.

An even bigger problem is that when public health centres prepare noise study programmes, they often do not even require assessing whether the noise is impulsive. If this is not determined at the start of the study, the corrections provided in the methods are not applied later either.

Example:

During the day, loading pipes at a warehouse produces an equivalent noise level of 53 dBA at a residential area 100 metres from the source. However, individual impacts reach much higher instantaneous L_AMAX levels – for example up to 90 dBA at the house. Such impacts not only disturb residents' sleep but can seriously affect their psychological wellbeing. Residents perceive them as constantly repeating banging, even though the daily average may not breach the hygiene norm.

With maximum sound level limits removed, the only real protection for residents against impact noise is a properly conducted noise study that identifies the occurrence of impulsive sounds and applies all the corrections provided in the methods.

Impulsive noise can usually be reduced

Experience shows that impulsive noise is often not an unavoidable part of the technological process. Once the sources of impulsive sound are identified, an industrial facility can be made much quieter by changing processes and using vibration and noise damping measures.

Detailed acoustic studies that identify sources of impulsive sound should therefore become a tool for finding the real causes of noise and proposing effective solutions.

Transport noise assessment becomes much more complex

Another very important change in HN 33:2026 is the assessment of transport noise using the long-term indicators L_D, L_V, L_N and L_DVN.

This means that a short-term measurement of, for example, 10–30 minutes – which until now was in most cases sufficient for a representative assessment of road traffic noise – is no longer enough.

L_D, L_V, L_N and L_DVN are long-term noise indicators, so determining them requires much more complex noise studies and longer data analysis. Such studies are considerably more expensive for state institutions, businesses and residents alike.

Such measurements can undoubtedly be more accurate and better reflect the long-term effect of noise. The question, however, is whether the additional costs and much more complex procedures will bring proportionate benefits to society. When assessing any regulatory change, it is important not only to aim for greater accuracy but also to ensure that the measures are economically justified.

Noise modelling – one of the biggest gaps in HN 33:2026

In modern practice, more and more decisions are based not only on noise measurements but also on noise modelling results. Noise barriers are designed, and new streets, railways, industrial facilities and the protection of residential areas are assessed, on the basis of modelling data.

It is therefore especially important that noise modelling is carried out according to clear quality criteria.

However, HN 33:2026 essentially sets no requirements for the competence of organisations or the quality control of noise modelling. This raises the question of how the reliability of different models and the comparability of results are ensured.

The wider context is also interesting. Travelling through Poland, Austria or Czechia, it is obvious that far more noise barriers have been installed along motorways than in Lithuania.

Why is that? Is the transport noise problem objectively smaller in Lithuania? Car noise levels are, after all, the same. Were the regulations in force for many years applied differently? Or did the noise modelling results used in some projects not always reflect real noise propagation accurately enough?

If noise modelling is one of the most important decision-making tools, the state should ensure clear quality requirements, competence assessment and control of modelling results. Only then will noise studies, acoustic studies and noise modelling truly serve their main purpose – protecting public health.

Conclusions

HN 33:2026 marks a significant change in environmental noise regulation. With maximum sound pressure level limits removed, professionally performed noise measurements become even more important.

The success of the new hygiene norm will depend not only on the wording of the legislation but also on how it is applied in practice. Properly identified impulsive noise and the reliable work of accredited laboratories and noise modelling providers become the key tools for ensuring real protection of residents from harmful environmental effects.

Planning an activity in Lithuania? We carry out accredited noise measurements and noise modelling according to HN 33:2026. Contact us.