Specifying acoustic fencing
Practical guidance for acoustic consultants, architects and project teams, from first noise assessment to the specification clause.
DLR, explained
DLR is the single-number rating of a barrier's airborne sound insulation, measured in a laboratory. For roads it is tested to BS EN 1793-2; for railways to BS EN 16272-2, which weights the result against a rail noise spectrum. A higher DLR means less sound passes through the barrier itself.
DLR is not the noise reduction a neighbour will hear. That depends on barrier height, length and position relative to the source and receiver, which the acoustic consultant models. As a rule of thumb, a 10dB reduction is perceived as roughly halving loudness.
Reflective or absorptive?
Reflective barriers stop sound passing through and reflect it back towards the source. Absorptive faces, rated by DLα, soak up part of that sound and help where reflections could reach homes on the other side of a road or site.
Bring us in early
Barriers are often added late, after planning conditions are set. Involving us at design stage means heights, post types, gates and access are resolved before they affect cost. To give you a recommendation we need:
- The acoustic report or the required DLR and barrier height.
- A site plan with barrier runs, corners, gates and ground levels.
- Site exposure (open, rural, urban, coastal) for post sizing.
- Programme and any site-specific rules (rail, highways, energy).
Read our longer guide: Specifiers guide to acoustic fencing.
Frequently asked questions
What is DLR in acoustic fencing?
DLR is the single-number laboratory rating of a barrier's airborne sound insulation, in decibels. Road barriers are tested to BS EN 1793-2 and rail barriers to BS EN 16272-2.
Is DLR the same as the noise reduction I will hear?
No. DLR rates the barrier itself. The reduction at a home or receiver depends on the barrier's height, length and position, which an acoustic consultant models.
What information do you need to recommend a barrier?
The acoustic report or required DLR and height, a site plan with runs, gates and levels, the site's wind exposure and any sector-specific requirements.
Specifying or pricing a barrier?
Send us the acoustic report or drawings and we will come back with a system, heights and post sizes to suit.