When converting or subdividing a building into flats or multiple dwellings, one requirement looms large for developers, architects, and homeowners alike: Part E of the Building Regulations. In plain terms, Part E stipulates that sound must be controlled between separate dwellings (walls, floors, ceilings) to give occupants privacy and reduce disruptive noise transmission.

At Pro Soundproofing Ltd, we specialise in delivering cost-effective, high-performance soundproofing solutions that meet or exceed these standards. Below is a guide to what Part E demands, why many projects struggle to comply, and how you can achieve compliance without sacrificing space or budget.

What Is Part E and Why Does It Matter?

• Part E (Approved Document E) is the section of the English & Welsh Building Regulations covering resistance to the passage of sound in residential buildings.

• It has two main aspects for most conversions:
    • E1 – separation of dwellings (walls, floors, ceilings) to control airborne noise and impact noise
    • E2 – internal separation within a dwelling (e.g. internal partitions)

• To comply, you must ensure that separating walls/floors reduce airborne noise sufficiently, and floors also suppress impact sounds (footsteps, dropped objects).

• Typical performance targets under Part E are:
    • Separating walls: around 45 dB airborne sound insulation (new builds), or ~43 dB for conversions.
    • Separating floors: similar airborne target, plus impact sound ceilings (L′nT,w) thresholds (~62–64 dB or better).

• In many refurbishment or conversion projects, you are required to carry out pre-completion acoustic testing to prove compliance.

Failing to satisfy Part E can lead to delays, increased costs, or refusal of certificate of occupancy. That’s why getting the acoustic design right from the start is vital.

Why Many Projects Fail or Overpay for Part E

1. Poor system selection or under-specification
   Choosing generic or “budget” acoustic products without verifying their lab-tested performance with your exact build-up can lead to a failure at test time.

2. Flanking paths and sound leaks
   Even if a wall or floor is well designed, sound can bypass it via adjacent structure (e.g. junctions, edges, pipework, services). These “leaks” often doom compliance unless carefully addressed.

3. Insufficient decoupling, damping or mass
   Relying on a single acoustic layer or ignoring vibration control can drastically reduce effectiveness.

4. Loss of ceiling height or floor level
   Some systems require thick build-ups which may not be tolerable in existing buildings; without a slim but effective system, clients may compromise unnecessarily.

5. Late integration of acoustic design
   If the acoustic solution is considered only after structural, M&E, or layout decisions, it often collides with constraints and forces expensive rework.

At Pro Soundproofing Ltd, we’ve seen all of these pitfalls. Our goal is to avoid them by designing bespoke systems that match the existing structure, client budget, and regulatory target.

Our Approach: Smart, Space-Saving, Compliant Solutions

Here’s how we tackle Part E soundproofing in real projects:

Ceiling / Floor Systems

• Where the ceiling below cannot be lifted too far, we use isolation clip systems that allow a slim drop – sometimes as low as ~10 mm below joists — while still maintaining high acoustic performance.

• If the ceiling is already fixed, or for floors above, we offer floating floor systems with acoustic mats/cradles or decoupling layers to suppress both airborne and impact noise.

• By selecting systems matched to whether the structure is timber or concrete, we avoid over-engineering and keep build-up to the minimum.

Separating Walls

• Depending on whether your party walls are masonry or stud, we decouple plasterboard layers using resilient mounts or isolation brackets, layering high-density boards plus mineral wool internally.

• For conversions, we often avoid thick masonry rebuilds by using light but high-performing partition systems that still meet Part E.

• All junctions, perimeter edges, and service penetrations are sealed with acoustic sealants to prevent flanking leaks.

Tailored Design & Testing

• Before any work, we perform a site survey, capturing the existing structure, ceilings, M&E routes, and potential weak spots.

• We model expected performance (airborne and impact) based on lab data and adapt our system selection accordingly.

• After installation we coordinate or assist with acoustic testing (airborne and impact) to demonstrate compliance.

By combining precision design, tested materials, and careful installation, we frequently deliver Part E compliance without excessive loss of space or ballooning budgets.

Real-World Example: A Flat Conversion with Minimal Ceiling Loss

Recently we worked on converting a two-storey building into flats. The ground floor ceiling originally sat just 2.4 m above the finished floor, so we had very tight headroom margins. After our survey we designed a ceiling isolation system using slimline rubber clips with staggered boards and dense mineral wool. The total drop was only ~25 mm, but the acoustic test results exceeded required Part E targets for both airborne and impact noise. The client was delighted – they gained compliant separation yet retained nearly full ceiling height.

Why Choose Pro Soundproofing Ltd for Your Part E Work

• Expert acoustic insight – we understand how sound behaves and what lets systems perform under real conditions

• Cost-aware solutions – our aim is to achieve compliance with the smartest system, not necessarily the most expensive

• Minimal disruption & space loss – we specialise in slim systems for tight builds

• Full support & accountability – from design, installation through to testing and certification

If you’re planning a conversation, refurbishment, or development where Part E compliance is required, get in touch for a free consultation. We’ll help you meet the regulations confidently – and keep peace between neighbours.