What does Part E of Building Regulations require?

Approved Document E (England & Wales) sets minimum airborne sound insulation standards for separating walls and floors between dwellings. New-build separating walls must achieve DnT,w + Ctr >= 45 dB (field test). New-build separating floors must achieve DnT,w + Ctr >= 45 dB airborne and L'nT,w = 43 dB walls / 43 dB floors. Scotland (Section 5) and Northern Ireland have similar requirements.

Why do I need resilient bars?

Resilient bars (also called resilient channels) mechanically decouple the plasterboard from the studs or masonry, breaking the vibration path for sound transmission. Without them, sound travels directly through the rigid connection between board and structure. A resilient bar system typically adds 5-10 dB of sound insulation improvement. They are essential for achieving Part E compliance in most wall build-ups.

What spacing should resilient bars be at?

For standard Part E separating walls, resilient bars at 600mm vertical centres are typical. For enhanced acoustic performance (bedrooms, studios), reduce spacing to 400mm or even 300mm centres. The bars are fixed horizontally across the studs or masonry, with the plasterboard screwed only to the bars — never directly to the studs, as this would create a sound bridge.

What type of acoustic sealant do I need?

Use a dedicated acoustic sealant (not standard silicone or decorator's caulk) around the full perimeter of every acoustic wall — floor, ceiling, and wall junctions. Acoustic sealant remains permanently flexible and seals air gaps that would otherwise allow flanking sound transmission. Popular UK brands include Soudal Acoustic Sealant and Green Glue. Apply a continuous bead at every board edge.

Can I use standard plasterboard for acoustic walls?

While standard plasterboard provides some sound insulation, dedicated acoustic plasterboard (such as Gyproc SoundBloc or Knauf Soundshield) contains a higher-density core that significantly improves sound reduction. British Gypsum states SoundBloc provides approximately 10% better sound insulation than standard wallboard in tested systems. For Part E compliance, acoustic board is strongly recommended and often required by the tested system specification.

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Acoustic Plasterboard Calculator — Part E Sound Insulation

Calculate acoustic plasterboard, resilient bars, and acoustic sealant for Part E compliant wall and ceiling systems.

Wall/Ceiling Area

Total area to be lined with acoustic board

Wall Perimeter

Total perimeter for sealant calculation

Acoustic TargetDetermines board layers and bar spacing

Price Per Board (optional)

Per sheet of acoustic plasterboard

How We Calculate This

This calculator sizes all components for an acoustic plasterboard system that meets Approved Document E (Part E) of the Building Regulations. It calculates board quantities, resilient bar lengths, acoustic sealant tubes, and screw counts based on your wall area and target sound rating.

The formula

Boards = (Wall area ÷ 2.88 m²) × Layers × Wastage factor

Resilient bar quantity is calculated from the number of horizontal rows (wall height ÷ bar spacing) multiplied by wall width. Acoustic sealant is based on the total perimeter length at 15ml per linear metre per layer of board.

System configurations

Separating wall (45 dB): 2 × 12.5mm acoustic board + resilient bar at 600mm
Separating floor (43 dB): 2 × 12.5mm acoustic board + resilient bar at 400mm
Enhanced bedroom (50 dB): 2 × 15mm acoustic board + resilient bar at 400mm
Studio (55+ dB): 3 × 12.5mm acoustic board + resilient bar at 300mm