Understanding TGD-E: Acoustic Compliance for Residential Developments

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What is TGD-E?

Technical Guidance Document E (TGD-E) sets out the requirements for sound insulation and acoustic performance in buildings in Ireland, supporting Part E of the Building Regulations.

It defines how buildings must be designed and constructed to:

  • Limit sound transmission between dwellings
  • Control impact noise from floors and stairs
  • Manage reverberation in shared internal areas

TGD-E applies primarily to:

  • New residential developments
  • Apartment buildings and multi-unit schemes
  • Material change of use to residential
  • Certain extensions adjoining other dwellings.

For developers, design teams, and contractors, compliance with TGD-E is essential to achieve regulatory approval, avoid costly remedial works, and ensure occupant comfort.

Key Objectives of Part E of the Building Regulations

TGD-E supports two core regulatory requirements:

E1 – Sound Insulation

  • Buildings must achieve reasonable resistance to airborne and impact sound transmission between adjoining dwellings or rooms.
  • Applies to:
    • Walls between dwellings
    • Floors (including separating floors and stairs)
    • Junctions and flanking paths
    • Walls & Floors Between Dwellings and Other Space

E2 – Reverberation Control

  • Internal common areas must be designed to limit reverberation and noise build-up that could affect adjacent dwellings.

The Core Acoustic Requirements

TGD-E focuses on three fundamental acoustic considerations:

1. Airborne Sound Insulation

This relates to noise transmitted through walls and floors, such as:

  • Speech
  • TV or music
  • General living noise

Typical requirements include:

  • ≥ 53 dB DnT,w between dwellings

2. Impact Sound Insulation

Impact noise occurs from physical contact with building elements, such as:

  • Footsteps
  • Dropped objects
  • Furniture movement

Typical requirements include:

  • ≤ 58 dB L’nT,w for floors

3. Reverberation in Common Areas

Common areas such as:

  • Corridors
  • Stairwells
  • Entrance lobbies

must be designed to reduce echo and noise build-up through acoustic absorption treatments.

Structure of TGD-E (Understanding the Sections)

TGD-E is divided into clear sections that guide compliance from design through to completion:

Section 0 – General Guidance

  • Definitions and scope
  • Sound transmission mechanisms:
    • Direct transmission
    • Flanking transmission
  • Design considerations (layout, services, junctions)

Section 1 – Performance Requirements

  • Sets minimum acoustic targets
  • Defines compliance routes:
    • Robust construction details
    • On-site testing

Section 2 – Testing and Verification

  • Mandatory pre-completion sound testing
  • Specifies:
    • Number of tests required
    • Testing standards (EN ISO methods)
    • Reporting procedures
  • Includes provisions for:
    • Failed tests
    • Remedial action

Section 3 – Separating Walls

  • Acceptable wall constructions:
    • Masonry
    • Cavity walls
    • Timber frame systems
  • Key considerations:
    • Mass and density
    • Junction detailing
    • Flanking control

Section 4 – Separating Floors

  • Floor construction types:
    • Concrete floors
    • Timber floors
  • Includes:
    • Impact sound control
    • Floor finishes and overlays
    • Ceiling treatments

Additional Technical Elements

  • Flanking transmission control (critical compliance risk)
  • Construction detailing and workmanship
  • Approved or “deemed-to-satisfy” solutions

Testing Requirements under TGD-E

All applicable residential developments must demonstrate compliance through:

  • On-site acoustic testing prior to completion
  • Testing of:
    • Airborne sound insulation
    • Impact sound insulation
  • Representative sample testing across units

Why TGD-E Compliance Matters

Failure to properly address TGD-E can result in:

  • Failed acoustic tests
  • Delays in project completion and sign-off
  • Costly remedial works
  • Poor occupant experience

Conversely, good acoustic design delivers:

  • High-quality living environments
  • Reduced complaint risk
  • Increased asset value and marketability

Wave Dynamics Approach to TGD-E Compliance

Wave Dynamics are highly experienced in delivering TGD-E compliant projects. Our consultants have delivered more than 60,000 residential units since 2015 when the regulations came in. Wave Dynamics have extensive experience in Value Engineering in residential having worked with our clients on VE to acheive the acoustic targets for our projects as cost efficient as possible.

At Wave Dynamics, we integrate TGD-E requirements into every stage of project delivery:

Design Stage

  • Acoustic strategy aligned with TGD-E
  • Junction and flanking risk assessments
  • Coordination with architectural and M&E design
  • Facade Acoustics.

Construction Stage

  • Site inspections and compliance audits
  • Contractor guidance on detailing
  • Early identification of acoustic risks

Pre-Completion

  • Independent acoustic testing
  • Troubleshooting and remedial strategy if required
  • Clear, defensible compliance reporting

Future Trends in Acoustic Compliance

While TGD-E sets the minimum standard, projects are increasingly targeting:

  • Enhanced acoustic performance beyond compliance
  • Alignment with:
    • BS 8233
    • BREEAM, LEED and WELL
    • HPI (Home Performance Index)

This reflects growing expectations around wellbeing, ESG performance, and building quality.

Conclusion

Technical Guidance Document E is the cornerstone of acoustic compliance in Ireland, ensuring that residential buildings provide a reasonable standard of sound insulation and internal acoustic comfort.

However, achieving compliance goes far beyond meeting minimum values — it requires:

  • Thoughtful design
  • Robust detailing
  • Quality construction
  • Expert testing and verification

Wave Dynamics provides end-to-end acoustic consultancy to ensure your project achieves compliance efficiently, avoids risk, and delivers a high-quality acoustic environment.