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Meeting Part E Building Regulations
If you are an architect or developer, sound insulation is not a nice to have, it is the law. Meeting Part E building regulations is a required step on almost every project that creates homes next to one another, and getting it wrong is expensive, because a failed sound test means remedial work and delays before building control will sign the building off.
The good news is that it is very achievable once you understand what the regulations are actually asking for. This guide explains Part E in plain terms for the people who have to design and build to it, and how Quietco helps developers pass first time.
What Part E Covers, Airborne and Impact Sound
Approved Document E, the resistance to the passage of sound, sets the standards for sound insulation between homes. It applies to the separating walls, floors and ceilings of new build attached dwellings and flats, and to conversions, and it deals with two very different kinds of noise.
Airborne noise is sound that travels through the air, such as conversation, television and music. Impact noise is structure borne, the footsteps, moving furniture and banging that travel through the building itself, and it is usually the harder of the two to control.
The two are measured differently. Airborne insulation is expressed as DnT,w + Ctr, where a higher figure is better, and impact is expressed as L’nT,w, where confusingly a lower figure is better. For new build separating floors the targets are at least 45 dB airborne and no more than 62 dB impact, while conversions are held to 43 dB and 64 dB.
How You Prove Compliance
Meeting the standard on paper is not enough, you have to demonstrate it. There are two routes. The first is pre-completion sound testing, where an accredited tester measures the finished separating walls and floors before the property is occupied.
The second, for new build attached dwellings, is the Robust Details scheme, an alternative that lets developers register approved constructions and avoid the uncertainty of on-site testing. Either way, the acoustic result forms part of building control sign off, much like an electrical certificate does.
It is worth knowing where projects usually fall down. Most test failures come not from the wrong system but from poor airtightness, small gaps at junctions and service penetrations, and from flanking sound travelling around the separating element rather than through it.
Change of Use, Where Developers Get Caught
Part E is easy to overlook on a conversion, which is exactly where a lot of developers get caught out. A material change of use, such as turning a terraced house into flats or an HMO, or an old office or factory into apartments, triggers the regulations just as a new build does.
That means every separating floor between the new units has to perform, and be proven to. The same thinking also pays off in a detached home, where a well designed separating floor stops you hearing people moving around upstairs or the television below. You can see how we approach this on our floors page.
Why a Floating Floor Wins
For separating floors, a floating floor is one of the most effective and space efficient ways to meet the standard. The principle is simple: the finished floor is isolated from the joists and from the walls all around the room, resting on a resilient layer rather than being fixed down, so impact vibration is absorbed instead of passed into the structure.
The best results come from combining acoustic treatment between the joists with that floating floor above, which tackles a wide range of the everyday frequencies that cause complaints. Modern direct to joist systems do all of this while staying slim, so you gain the performance without losing much room height at all.
Fill out the contact form to book your FREE noise diagnosis call and talk through your project. Get in touch here.
How We Help Architects and Developers
We work with architects and developers in three ways. We can review your specifications so you do not design in materials that make noise worse, we can carry out the installation for you, and we can teach your team through our soundproofing course.
If you are specifying a scheme, or converting a building and need it to pass first time, the earlier we are involved the better. Take a look at the soundproofing course if you want to build the knowledge in house, or book a consultation to talk about a live project.
Fill out the contact form to book your FREE noise diagnosis call and give your development the best chance of passing. Contact us here.
Frequently Asked Questions
What is Part E of the building regulations?
Part E, or Approved Document E, sets the sound insulation standards for separating walls, floors and ceilings between homes. It covers both airborne noise, like voices and TV, and impact noise, like footsteps.
Do I need a sound test for meeting Part E building regulations?
Usually yes. You either arrange pre-completion sound testing or, for new build attached dwellings, use the Robust Details scheme as an alternative, and the result feeds into building control sign off.
Does converting a house into flats or an HMO trigger Part E?
Yes. A material change of use, such as creating flats or an HMO, triggers Part E just as a new build does, so the separating floors must perform and be demonstrated to comply.
What is the difference between airborne and impact sound?
Airborne sound travels through the air, such as conversation and music, while impact sound travels through the structure, such as footsteps. They are measured separately and need different design responses.
How much floor height does a soundproof separating floor take up?
Less than most people expect. Modern direct to joist floating floor systems are slim, so you can meet the standard without losing much room height.
