My walls have a good sound insulation rating, so why is my open kitchen so noisy?

An insulation rating describes how much sound a wall blocks between rooms; it says nothing about how sound behaves once it is already inside a room. An open kitchen and living room finished mostly in hard surfaces will feel loud and echoey regardless of wall performance, because there is nothing in the room to absorb the sound bouncing around it.

What is the cheapest way to calm down an already-built noisy room?

Add soft, absorbent surface: a large rug over a hard floor, substantial curtains, an upholstered sofa, and shelving with books or open objects rather than bare walls. None of it requires construction work, and together these additions noticeably shorten reverberation time in a typical living space.

Do I need to worry about the WC location during design, or can it be decided later?

It should be decided during layout design. A waste stack routed through a partition wall, or a WC placed directly against a bedroom, is very difficult and disruptive to correct once the walls, screed and services are built; moving a stack after handover usually means opening the floor and the wall it runs through.

Is a heavier partition wall worth the extra cost between a bedroom and a living room?

Usually yes, and the timing matters more than the cost itself. The price difference between a standard partition and a heavier, decoupled one is small at the framing stage and essentially irreversible once the wall is finished, so it is worth specifying correctly the first time rather than living with the result.

Does the flooring choice affect what I hear from the room below?

It affects impact sound specifically, footsteps, dragged chairs, dropped objects, which is a distinct topic covered under impact sound insulation . The finish itself matters less than the resilient layer and floor build-up underneath it, which has to be decided before the screed is poured.

Will a well-sealed building envelope also fix noise from traffic outside?

It goes a long way for airborne traffic noise, but whether it is sufficient, and what limits apply, is assessed through a dedicated noise study rather than left to a general assumption about envelope performance.

Interior acoustic comfort

Interior acoustic comfort covers two problems: reverberation inside a room, fixed with absorbent surfaces, and sound transmission between rooms, fixed with mass, decoupling and sealed junctions.

What is interior acoustic comfort?

Interior acoustic comfort is the combined experience of how a room sounds to be in and how well it keeps sound out of, and inside, its neighbours. It is not one property but two, and confusing them is the single most common mistake clients make when a finished house does not feel quiet: they assume that a well-insulated house is automatically a pleasant-sounding one, and it is not.

The first problem is room acoustics: how sound behaves once it is already inside a room, how long it lingers, and whether a conversation across a table competes with echo off the walls. The second is sound transmission: how much of the noise generated in one room reaches the next one, through the air, through the structure, or around the partition that was meant to stop it. A house can solve one of these completely and still fail the other.

How is acoustic comfort different from sound insulation?

Sound insulation is a property of a wall, floor or door: how much airborne or impact sound it blocks between two spaces, a performance that a heavier, better-detailed construction improves. Acoustic comfort is a property of the finished, furnished, lived-in room: whether people inside it can hear each other clearly, whether the space feels calm or jangly, and whether the room next door disturbs it. A partition can carry an excellent insulation rating on paper and still sit inside a kitchen and living room that are acoustically miserable, because reverberation is governed by the surfaces inside the room, not by what is inside the wall. The two problems are solved with different means, at different stages, often by different people, and treating them as one topic is how a finished house ends up with a wall that performs but a room that does not.

Why does a hard-finished open-plan kitchen and living room feel exhausting?

An open day zone finished in tile, stone, glass and painted plaster has almost nothing in it to absorb sound. Every voice, chair scrape and running tap reflects off every hard surface repeatedly before it decays, which raises reverberation time and directly reduces speech intelligibility: people start raising their voices to be heard over a room that will not settle down, which raises the ambient noise further still. This has nothing to do with what is built into the walls or the floor structure; a house with excellent sound insulation between rooms can still have a single hard-surfaced open-plan room that is unbearable to hold a conversation in.

The fix is absorption, not insulation: soft, porous material somewhere in the room's surfaces, and this is exactly where acoustic comfort collides with the material palette. A minimal interior built almost entirely from hard, reflective finishes is, acoustically, the worst case a residential room can be in, regardless of how good it looks in a photograph.

What separates room acoustics from sound transmission between rooms?

Problem	Typical symptom	Root cause	What fixes it	When it must be decided
Room acoustics	Echo, raised voices, poor speech clarity in a shared space	Too little absorbent surface relative to room volume	Textiles, upholstery, rugs, acoustic ceiling or wall panels, open shelving	Interior fit-out stage; can still be corrected after handover
Airborne sound transmission	Voices, television or music clearly audible in the next room	A partition too light, or with gaps and penetrations, for the noise source	Heavier or multi-leaf partition construction, sealed junctions and doors	Design stage; largely fixed once the partition is built
Flanking transmission	Sound heard next door despite an apparently solid partition	A continuous screed, shared ceiling void, services riser, back-to-back sockets or an undersealed door carrying sound around the wall	Breaking the continuous path: floating floor, isolated riser, staggered sockets, a door with a proper seal	Design and detailing stage, before the screed and services are fixed
Impact sound	Footsteps, dragged chairs or dropped objects heard from the room below	Structure-borne vibration entering the floor slab, covered in depth by impact sound insulation	Resilient layer under the floor finish, decoupled floating floor build-up	Floor build-up stage, before screed is poured

Which interior surfaces absorb sound, and which reflect it?

Surface type	Examples	Qualitative effect on the room
Hard and reflective	Tile, stone, glass, painted plaster, polished concrete	Reflects nearly all sound striking it; raises reverberation time
Semi-hard	Timber floor and panelling, veneered furniture	Mostly reflective, with a small absorbent contribution
Textile and upholstered	Sofas and armchairs, curtains, rugs over a hard floor	Noticeably absorbent; the most cost-effective retrofit for an existing room
Open and irregular	Open bookshelves, loosely arranged objects	Diffuses and partially absorbs sound, breaking up flat reflective surfaces
Purpose-made acoustic surfaces	Acoustic ceiling rafts, perforated or felt wall panels	Highly absorbent; used where furnishing alone cannot bring reverberation down enough

Which layout decisions in a family house determine acoustic comfort later?

Several decisions made at the drawing stage set the acoustic outcome of a house long before anyone chooses a sofa. Placing a bedroom directly next to a living room, or next to a bathroom, puts a night zone against exactly the rooms most likely to generate noise in the evening; where the plan allows it, a dressing room, a store, or the stair itself is a better buffer between the two. A waste stack for a WC running inside a partition wall rather than a service duct turns that wall into a flanking path for a very specific, recognisable noise every time it is used. A home office needs a door that actually seals, not just closes, if a call in one room should not be audible as background noise in the next; a door leaf sized for acoustic performance, not for cost, and a proper threshold seal are both decided at the joinery specification stage, not on site. And a heavier partition with a decoupled lining is a modest, almost invisible cost difference during construction; once the plasterboard is closed up and the family has moved in, the same improvement means demolition, so this is a decision that has to be made before the wall is built, not after someone complains about it.

Is outdoor noise the same problem?

No, and it is worth separating clearly. Everything above concerns noise generated inside the house, between its own rooms. Noise arriving from outside, road or rail traffic being the most common case in Slovakia, is assessed and limited under separate legislation, covered in detail under noise study. A house can pass every outdoor noise requirement at the permit stage and still have poor acoustic comfort between its own rooms, because the two are governed by different physics, different standards and, usually, different consultants.

Frequently asked questions

My walls have a good sound insulation rating, so why is my open kitchen so noisy?: An insulation rating describes how much sound a wall blocks between rooms; it says nothing about how sound behaves once it is already inside a room. An open kitchen and living room finished mostly in hard surfaces will feel loud and echoey regardless of wall performance, because there is nothing in the room to absorb the sound bouncing around it.
What is the cheapest way to calm down an already-built noisy room?: Add soft, absorbent surface: a large rug over a hard floor, substantial curtains, an upholstered sofa, and shelving with books or open objects rather than bare walls. None of it requires construction work, and together these additions noticeably shorten reverberation time in a typical living space.
Do I need to worry about the WC location during design, or can it be decided later?: It should be decided during layout design. A waste stack routed through a partition wall, or a WC placed directly against a bedroom, is very difficult and disruptive to correct once the walls, screed and services are built; moving a stack after handover usually means opening the floor and the wall it runs through.
Is a heavier partition wall worth the extra cost between a bedroom and a living room?: Usually yes, and the timing matters more than the cost itself. The price difference between a standard partition and a heavier, decoupled one is small at the framing stage and essentially irreversible once the wall is finished, so it is worth specifying correctly the first time rather than living with the result.
Does the flooring choice affect what I hear from the room below?: It affects impact sound specifically, footsteps, dragged chairs, dropped objects, which is a distinct topic covered under impact sound insulation. The finish itself matters less than the resilient layer and floor build-up underneath it, which has to be decided before the screed is poured.
Will a well-sealed building envelope also fix noise from traffic outside?: It goes a long way for airborne traffic noise, but whether it is sufficient, and what limits apply, is assessed through a dedicated noise study rather than left to a general assumption about envelope performance.