How to Soundproof Walls to Meet Building Regulations Part E: A Complete Guide

Understanding Building Regulations Part E for Acoustic Performance

Building Regulations Part E sets the minimum standards for sound insulation in new builds and conversions across England and Wales. Whether you're a contractor, developer, or self-builder, achieving compliance requires careful material selection and proper installation techniques.

In this comprehensive guide, we'll walk you through the exact specifications, materials, and methods needed to meet—and exceed—Part E requirements for separating walls and internal partitions.

What Are the Part E Requirements for Walls?

Part E specifies minimum airborne sound insulation values measured in decibels (dB). For separating walls between dwellings, you must achieve:

• 45 dB DnT,w + Ctr for airborne sound insulation in new builds
• 43 dB DnT,w + Ctr for conversions and material changes of use

These values represent the weighted standardized level difference—essentially, how much sound is blocked between adjacent properties.

Proven Wall Systems That Meet Part E

There are two primary approaches to achieving Part E compliance: masonry-based systems and lightweight stud wall systems with acoustic enhancement.

1. Masonry Cavity Wall Systems

Traditional masonry construction using dense blockwork (100mm minimum each leaf) with a 50mm cavity can achieve Part E standards when properly constructed. The mass of the blocks provides natural sound attenuation.

To enhance performance, consider filling the cavity with mineral wool acoustic insulation. This absorbs sound energy within the cavity and prevents resonance, typically adding 3-5 dB of additional performance.

2. Lightweight Stud Wall Systems with Acoustic Membranes

For timber or metal stud partitions, achieving Part E requires a multi-layer approach:

• High-density acoustic plasterboard (15mm minimum) on both sides
• Mass-loaded barrier membranes applied between plasterboard layers
• Acoustic mineral wool (60-100mm) within the stud cavity
• Resilient bars or channels to decouple the plasterboard from the studs

This combination of mass, absorption, and decoupling is essential for lightweight walls to match the performance of masonry.

The Role of Mass-Loaded Barriers in Part E Compliance

Mass-loaded vinyl (MLV) and high-density acoustic membranes are game-changers for achieving Part E in space-constrained projects. These thin, flexible materials add significant mass without consuming valuable floor area.

A quality 5kg/m² acoustic membrane can improve sound insulation by 5-8 dB when correctly installed between plasterboard layers. Self-adhesive versions simplify installation and ensure consistent coverage without gaps.

Installation Best Practices for Maximum Performance

Even the best materials will underperform if installation isn't executed properly. Follow these critical guidelines:

• Seal all penetrations: Electrical boxes, pipes, and cables create acoustic weak points. Use acoustic sealant around all penetrations.
• Avoid rigid connections: Use resilient mounts for fixtures and maintain acoustic breaks between wall layers.
• Stagger joints: Offset plasterboard joints between layers to prevent sound flanking.
• Fill perimeter gaps: Use acoustic sealant or expanding foam at wall-to-floor and wall-to-ceiling junctions.
• Maintain cavity integrity: Don't bridge the cavity with mortar snots or debris in masonry walls.

Pre-Completion Testing: Ensuring Compliance

Building Control requires pre-completion sound testing for most new builds and conversions. Testing is conducted by qualified acoustic consultants who measure the actual dB performance on-site.

Failures are costly—requiring remedial work, re-testing, and project delays. Investing in proven materials and proper installation from the start is always more economical than retrofitting.

Common Mistakes That Cause Part E Failures

We regularly see these issues lead to failed sound tests:

• Insufficient mass in lightweight stud walls
• Missing or poorly installed cavity insulation
• Gaps in acoustic membrane coverage
• Rigid connections between wall leaves
• Unsealed service penetrations
• Flanking transmission through floors or ceilings

Choosing the Right Materials for Your Project

Material selection should balance performance, cost, and buildability. For separating walls, prioritize:

• Density: Higher mass materials block more sound
• Decoupling: Resilient layers prevent vibration transfer
• Absorption: Mineral wool dampens sound within cavities
• Ease of installation: Self-adhesive membranes reduce labor and improve consistency

Contractor-grade acoustic solutions designed specifically for Part E compliance take the guesswork out of specification and ensure reliable results.

Conclusion: Meeting Part E with Confidence

Achieving Building Regulations Part E compliance for wall soundproofing requires understanding the standards, selecting appropriate materials, and executing proper installation techniques. By combining mass-loaded barriers, acoustic mineral wool, and resilient construction methods, you can confidently meet—and exceed—the required performance levels.

Whether you're working on new builds, conversions, or refurbishments, investing in proven acoustic solutions from the start ensures compliance, avoids costly failures, and delivers the quiet, comfortable spaces your clients expect.