You are lying in bed at eleven o’clock and can hear your neighbour’s television through the wall. Or you are sitting in the garden and cannot hold a conversation because the neighbour’s heat pump is constantly humming. Or you live in a flat and can hear every step from the flat above.
Noise in the home is not just annoying — it is a real health issue. Long-term noise exposure increases the risk of sleep problems, elevated blood pressure and stress.
Why does sound get through?
Sound moves as waves — both through air and through solid materials. There are two types of noise in homes:
Airborne sound spreads through air and penetrates walls, floors or ceilings. Music, conversations, television. The heavier and denser a structure is, the better it stops airborne sound. A solid concrete wall stops far more than a thin plasterboard partition.
Impact noise spreads directly through the structure. Footsteps on the floor, chairs scraping, a washing machine centrifuging. Impact noise is often more disturbing than airborne noise, because it is harder to insulate against.
The most common causes of neighbour noise:
- Thin floor decks — especially in flats from the 1950s–70s with concrete decks without impact sound deadening
- Lightweight partitions — plasterboard walls or lightly built masonry partitions with insufficient mass
- Air leakage — cracks, pipe and cable penetrations, back-to-back electrical sockets, draughty joints
- Flanking transmission — sound does not go through the wall but around it via floor, ceiling or adjacent structures
- External noise — neighbour’s heat pump, traffic, ventilation systems
What you can do indoors
1. Seal air leakage (cheapest)
Sound finds the smallest gap. Seal around pipes, cables, electrical sockets and doors. Acoustic sealant costs under 100 DKK and can dampen a surprising amount.
2. Secondary wall against the party wall (500–1,500 DKK/m²)
The most effective solution against airborne sound from the neighbour. A new plasterboard wall on a steel frame with mineral wool between, fitted with a gap from the existing wall. The heavier the plasterboard and the wider the cavity, the better the attenuation. You lose 5–10 cm of room depth.
3. Floating floor against impact noise (300–800 DKK/m²)
A new floor laid on an impact sound deadening underlay — typically cork, rubber or specialist foam — that decouples the floor covering from the concrete deck. It works best against impact noise from above, but ideally should be laid in the flat above you, not in your own.
4. Ceiling treatment (400–1,200 DKK/m²)
A suspended ceiling with sound insulation in the void can reduce both airborne and impact noise from above. It lowers the ceiling height by 5–15 cm, but may be the only option if the upstairs neighbour is unwilling to cooperate.
5. Heavy curtains and soft surfaces
Not a solution to the underlying problem, but heavy curtains, rugs and soft furniture absorb sound within the room and can make it more comfortable. They help most with reverberation and room acoustics.
External noise: heat pumps and traffic
Neighbour noise does not only come through walls. Heat pumps are a growing source of neighbour disturbance. According to the Danish Environmental Protection Agency’s guidelines, a heat pump may not exceed 35 dB(A) at the neighbour’s boundary. If the limit is exceeded, you can complain to the municipality.
Against traffic noise, new windows with acoustic glazing are the most effective solution. A window with acoustic units (with laminated glass and varied glass thicknesses) can reduce traffic noise by up to 40 dB — the difference between a busy road and a quiet garden.
What do the rules say?
- The Building Regulations (BR18) set requirements for sound insulation in new construction: at least 55 dB airborne sound insulation and no more than 53 dB impact noise level between flats
- Older homes are not subject to new requirements — many flats from the 1950s–70s fall far short of current standards
- Noise from neighbours is regulated by house rules (housing cooperatives and homeowners’ associations), police bylaws and in serious cases by neighbour law
- Noise from installations (heat pump, ventilation) is regulated by the Danish Environmental Protection Agency’s guidelines, and the municipality can intervene
Owner and housing cooperative associations
If you live in an owners’ or housing cooperative association, the association can decide to sound-insulate floor decks or shared partition walls as a common project. This is often cheaper per flat than individual solutions and gives a better result, because all sides of the structure are treated.
Check the association’s articles of association and house rules for noise limits and rules on conversion.
Which homes are most affected by noise?
- Apartment buildings from the 1950s–70s — built with concrete decks without impact sound deadening and lightweight partitions. Many residents can hear neighbours’ conversations and footsteps
- Older housing cooperative flats — often with original timber floors directly on beams, minimal sound insulation, and thin walls between flats
- Terraced houses with shared walls — the party wall is often just a single layer of brick or lightweight concrete, transmitting both airborne and impact noise
- Homes near busy roads — windows with single glazing or old sealed units are the weakest point in the building envelope against external noise
- Newer flats with open floor plans — large, hard surfaces (concrete, glass, tiles) reflect sound and amplify reverberation
Start with what you can hear
Listen: when is the noise worst? What type of sound is it — speech, footsteps, bass, humming? Does it come through the wall, floor, ceiling, window? The answer determines the solution.
And remember: a combination of small improvements — sealing, curtains, a thicker door — can together make a noticeable difference, even without major building work.
If you live in a flat, sound insulation can be incorporated into a comprehensive renovation. And if the noise is affecting your sleep, our guide to sleeping badly and the home provides further angles.
Sources: SBi “Sound insulation in prefabricated construction”, Danish Environmental Protection Agency, BR18, Bolius.