Vibration dose values and construction vibration limits

The vibration dose value is a cumulative measure of how much vibration a person is exposed to over a day or a night, expressed in m/s to the power 1.75. It is the figure used to judge whether people in buildings are likely to complain, and it is set out in BS 6472-1, the British Standard on human exposure to vibration in buildings from sources other than blasting.

It is not the same as peak particle velocity, and confusing the two is the commonest error in construction vibration submissions. One deals with people. The other deals with buildings.

What the value measures and why it accumulates

Peak measures record the worst instant. The dose value records the whole exposure period, weighting higher magnitudes far more heavily than lower ones through a fourth-power time integration.

That weighting has a practical consequence. A short burst of strong vibration contributes far more to the daily total than a long period of mild vibration, so a contractor who concentrates breaking into two intense hours may produce a worse result than one who spreads the same work across a day at lower intensity.

The standard separates daytime and night-time assessment periods, and the acceptable night-time figures are considerably lower because sleep disturbance is the concern. Where works run into the evening, the night period starts biting well before most site teams expect.

How it differs from peak particle velocity

Peak particle velocity, measured in millimetres per second, is the quantity used to assess the risk of damage to buildings. Guidance on cosmetic damage thresholds for residential structures sits in the British Standard on evaluation and measurement for vibration in buildings, and the thresholds are far above the levels at which people notice vibration and complain.

That gap is the source of most disputes. A site can be comfortably below any damage threshold and still generate a stream of complaints, because human perception begins at a small fraction of the level that affects plaster.

Assess both. A method statement that only addresses damage risk answers the wrong question for a planning condition about amenity.

Probability of adverse comment

BS 6472-1 frames its criteria as probabilities rather than pass or fail limits. Bands run from a low probability of adverse comment, through levels at which adverse comment is possible, to levels at which it is probable. For residences in the daytime, the commonly cited range for a low probability of adverse comment starts at around 0.2 to 0.4 m/s to the power 1.75, with night-time figures set substantially lower.

Two points follow from that framing. First, exceeding a band boundary is not a breach of anything; it is an indication that complaints become more likely. Second, the criteria say nothing about how many people are affected or how often, which is why the assessment has to describe the receiving population as well as the numbers.

Local authorities vary in how they apply the bands. Some adopt them directly in conditions, some set their own limits in a construction management policy, and some rely on statutory nuisance powers instead. Ask which applies before drafting the assessment.

Where the assessment sits in the application

Vibration is not a report type PlanScope produces, and on most schemes it does not need a standalone document. It appears as a section within the construction environmental information supporting an application, or within the acoustic assessment where the same consultant covers both.

That placement matters for validation. An authority's local list may ask for construction impacts to be addressed without naming vibration, and an applicant who answers only on noise will receive a query. Read the list carefully, and where the works involve piling, deep excavation or demolition next to occupied buildings, address vibration whether or not the list names it.

Sources on a construction site

The activities that generate complaints are predictable: percussive piling, vibro-compaction, breaking of concrete slabs and obstructions, sheet piling, dynamic compaction and heavy plant movement over uneven ground.

Design choices reduce exposure more effectively than management measures. Continuous flight auger piling in place of driven piling, hydraulic bursting in place of breaking, and pre-boring before driving all cut vibration at source. Where the ground conditions allow one of these substitutions, the assessment should say so explicitly, because a case officer reading it wants to see that the quiet option was considered and not simply priced out.

On sites with deep excavation, vibration interacts with the ground movement analysis. A Basement Impact Assessment and a construction vibration assessment share inputs and should be prepared together rather than by unconnected teams.

Monitoring and trigger levels

A workable monitoring regime has four elements: baseline measurement before works start, defined monitoring positions on or near the most sensitive receptors, trigger levels below the criteria at which action is taken, and a stated response when a trigger is reached.

Trigger levels are the part that gets skipped. Setting a trigger at the criterion itself means you only learn about a problem after it has happened. Setting it at a proportion of the criterion gives the site manager a chance to change method before complaints arrive.

The response protocol should name who is notified, what they are authorised to stop, and how the record is kept. Continuous monitoring with automatic alerts is now normal on urban sites and is far less expensive than a fortnight of complaints.

Where the works also generate noise, the two assessments belong in the same document as the Noise Impact Assessment, because mitigation for one frequently affects the other.

What the submission should commit to

A construction vibration section that satisfies an environmental health officer will usually contain:

1. Identification of sensitive receptors, including any vibration-sensitive equipment in nearby commercial premises.
2. Baseline conditions, measured rather than assumed, with dates and equipment specification.
3. Predicted levels for each significant activity, with the prediction method stated.
4. The criteria being applied, and their source, separating human response from building damage.
5. Monitoring locations, trigger levels and the response protocol.
6. A complaints procedure with a named contact and a response time.

Those commitments belong in a Construction Management Plan secured by condition, so that they bind the contractor rather than sitting in an application document nobody reads after determination.

One honest caveat: prediction of construction vibration is less precise than noise prediction, because ground transmission varies sharply over short distances. Build in monitoring and a willingness to change method, rather than relying on a prediction to hold.

This is general guidance rather than legal advice, and vibration criteria are applied by individual authorities, so check the position with your local planning authority or a qualified acoustician before relying on it.

PlanScope drafts construction and noise documents structured to UK planning policy, with monitoring data flagged rather than assumed. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.