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Site engineer measuring construction noise near an acoustic barrier and working excavator on a UK civil engineering site

Construction noise screening calculator

Combine evidenced source levels, distance, operating time and project-specific corrections to screen construction activity noise at a sensitive receptor.

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Planning screen, not a compliance assessment

Replace the example values with measured or otherwise justified project data. There is no universal construction noise limit, so this tool compares the result only with a target you enter from a planning condition, consent, management plan or acoustic assessment.

Activity noise at a receptor

LAeq,T is the energy-equivalent A-weighted sound-pressure level over interval T. Add up to eight sources that could operate during the same assessment period. Each reference level must represent that individual source during active operation at a known distance, not a level already averaged across inactive time or containing background and other plant.

Use the whole-minute period required by the project assessment.

No default target is assumed.

Source Distance change On-time change Project correction Contribution
Example source A-9.5 dB-3.0 dB0.0 dB67.4 dB(A)
Example source B-6.0 dB0.0 dB0.0 dB69.0 dB(A)

How the screening calculation works

The screen uses simplified point-source distance, on-time and energy-combination arithmetic. It is not a BS 5228 prediction or assessment, and project-specific acoustic judgement remains with the assessor.

1. Adjust for distance

For an entered reference sound-pressure level, the screen uses 20 x log10(reference distance / receptor distance). Doubling the distance reduces the level by about 6 dB. Use this only for a compact point-like source where both distances are in the acoustic far field and the measurement geometry remains comparable. Do not use it for inward extrapolation, a moving source, a line source or a different screening condition.

2. Adjust for on-time

The on-time correction is 10 x log10(on-time / assessment period). A source running for half the period contributes 3 dB less than the same source running continuously.

3. Apply evidenced corrections

Enter a signed project correction only where an acoustic assessment justifies it. Negative values can represent documented attenuation; positive values can represent effects such as a façade reflection. The tool does not guess either effect.

4. Combine sources by energy

Decibels cannot be added arithmetically. Each contribution is converted to sound energy, summed and converted back with 10 x log10(sum of 10^(level / 10)).

Choose defensible source data

The result is only as useful as the input evidence. Keep the level, operating condition, material, method and reference distance together in the project record.

Measured activity LAeq

Use a representative measurement for the same plant, task and operating condition, with the measurement distance recorded. Measure distance rather than estimating it.

BS 5228 or project library

Select a genuinely comparable dataset entry and retain its table reference. Historic generic data may not represent a newer attachment, enclosure, material or duty cycle.

Do not enter sound power directly

Sound power level, LWA, describes total acoustic output. This calculator expects an LAeq sound-pressure level at a known distance. Convert LWA through a competent BS 5228 method first.

Why the tool has no compliance flag

UK construction noise is assessed in context. Planning conditions, agreed working hours, existing sound levels, receptor sensitivity, activity duration and local authority requirements can all change the relevant test.

Use the project-specific target

The receptor is the exact assessment point, such as a boundary, garden or building façade position. Enter a target only when its metric, period, position and free-field or façade condition match the calculation. A daytime LAeq target cannot be reused automatically for an evening, night or short noisy activity.

Escalate complex cases

Use a competent acoustic consultant where sources move widely, barriers change, reflections or ground effects matter, tonal or impulsive character is important, or the site is close to homes, schools, hospitals or other sensitive uses.

Section 60 and Section 61 checks

  • Section 60 allows a local authority to control matters including plant, working hours, noise levels and steps to minimise noise from construction works.
  • Section 61 provides a route to apply in advance for consent covering the works and proposed noise-control method.
  • Local authorities commonly ask for a plant schedule, method, programme, receptor plan, prediction, monitoring proposal and control measures. Requirements vary, so confirm the receiving authority's process. The Bexley contractor guidance is one published example, not a national template.

Sources and scope

Links were checked on 30 August 2026. The arithmetic is a simplified screening implementation, not a reproduction of a complete BS 5228 assessment method.

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