Robust Details Scheme Explained

What This Requirement Covers

Robust Details Ltd (RDL) offers an alternative compliance route under Approved Document E that avoids the need for pre-completion sound testing. Instead, the builder uses approved construction details that have been tested and proven to consistently exceed the minimum sound insulation standards.

Key Requirements

How It Works

1. The developer registers the project with RDL and selects approved Robust Detail construction types for separating walls and floors
2. A registration fee is paid per plot (currently approximately GBP 40-50 per plot for walls and floors)
3. The approved construction details must be followed precisely during construction
4. RDL carries out site inspections during construction to verify that the details are being built correctly
5. If the construction passes inspection, no pre-completion sound testing is required
6. Building Control accepts the RDL inspection report in place of PCT results

Available Details

RDL publishes a handbook of approved details covering

1. Separating walls: Solid masonry, cavity masonry, timber frame, steel frame, and hybrid construction types
2. Separating floors: Concrete with soft covering, concrete with floating floor, timber frame with floating floor
3. Flanking construction: Specific requirements for external walls, internal walls, and junctions with the separating element

Advantages

1. No risk of failing a pre-completion sound test (which can delay handover and require expensive remedial work)
2. Consistent quality through standardised construction details
3. Site inspections provide quality assurance during construction
4. Lower overall cost for large developments (compared to testing every separating element)

Requirements

1. All registered details must be followed exactly; deviations from the approved detail are not permitted
2. RDL inspectors will check compliance at the appropriate construction stages
3. The developer must notify RDL when the construction is ready for inspection

Practical Compliance Tips

1. Decide between PCT and Robust Details at the design stage; Robust Details requires the design to match an approved detail
2. Train site teams in the specific requirements of the Robust Detail being used; common failures include incomplete mortar joints, missing insulation, and incorrect flanking details
3. Schedule RDL inspections at the correct construction stages; late notification can delay the inspection
4. If RDL identifies non-compliance, remedial work must be carried out before the inspection can be signed off
5. Robust Details is not available for building conversions; PCT is the only compliance route for conversions
6. Keep the RDL inspection reports for the building file and for Building Control
7. Compare the cost of RDL registration against the cost of PCT for your development to determine the most economic route