Construction noise limits and section 61 prior consent

Section 61 prior consent noise applications are the piece of construction consenting that developers most often skip and most often regret. Section 61 of the Control of Pollution Act 1974 lets the person who intends to carry out the works apply to the local authority for consent to the method, plant and hours before work starts. If consent is given, section 65 prevents the authority serving a section 60 notice in respect of the matters covered. That is the whole attraction: certainty about what you may do, and immunity from the notice that would otherwise arrive on the worst possible day.

The definition of noise in the Act includes vibration, so a consent covers piling vibration as well as airborne noise.

Why a prior consent is worth having

A section 60 notice is served after the fact and on the authority's terms. It can specify the plant to be used, the hours of work and the noise levels not to be exceeded, and there is no negotiation before it lands.

A section 61 consent inverts that. You propose the method, the authority tests it, and the terms are agreed in advance. Three practical advantages follow.

The programme becomes financeable, because the contractor knows which hours and which plant are permitted before pricing the job. Complaints become manageable, because an environmental health officer responding to a resident has an agreed document to point at. And compliance with the consent supports a best practicable means defence if a statutory nuisance complaint is later made under the Environmental Protection Act 1990.

It is not a universal answer. For a small extension the process costs more time than it saves. For demolition, piling, sheet piling, breaking out a basement or any work running close to occupied dwellings, it earns its keep.

What the application contains

Section 61 requires the application to be made before the works begin, and where building regulations approval is needed, at the same time as or after that application. Include the following.

1. A description of the works and the site, with a programme showing the noisy phases and their duration.
2. The plant to be used, item by item, with sound power levels from the manufacturer or from the data in BS 5228.
3. The method of working for each noisy activity, including the sequence and the location of plant.
4. Predicted noise levels at the nearest sensitive receptors, calculated to BS 5228-1, for each phase.
5. The steps proposed to minimise noise and vibration: acoustic screening, plant selection, hydraulic rather than percussive breaking, silenced generators, reversing alarms.
6. Proposed working hours, including any specific out of hours activities and why they are unavoidable.
7. Vibration predictions where piling, compaction or breaking out is proposed, assessed against BS 5228-2 and the human response guidance in BS 6472-1.
8. The monitoring proposed, with locations, trigger levels and the action to be taken when a trigger is reached.
9. A named contact and a complaints procedure.

The authority has 28 days to consider the application and give consent if it is satisfied. If it does not respond in that period, the applicant may appeal to the magistrates' court. Build the 28 days into the programme and submit before the contractor is on site rather than in the week before piling.

The ABC method for setting limits

Annex E of BS 5228-1 gives the assessment framework most authorities use, usually called the ABC method.

It works by selecting a category, A, B or C, according to the existing ambient noise level at the receptor, and then comparing the predicted construction noise against the threshold value for that category. Separate threshold values apply to daytime, to evenings and weekends, and to the night period. The thresholds rise as the existing ambient level rises, on the logic that a quiet residential street needs more protection than a site beside a dual carriageway.

Daytime thresholds sit in the mid-60s to mid-70s dB LAeq range, and night-time thresholds are far lower. Take the exact figures from the standard rather than from a previous report, because misquoted threshold values are a common reason an officer rejects an assessment.

Two points about using it well. The method is a significance test, not a limit, so a prediction above the threshold means a potential effect requiring mitigation rather than an automatic refusal. And the ambient level that sets the category has to be measured, not assumed, because choosing category C on the basis of a busy road 300 metres away will not survive scrutiny.

Working hours and out of hours working

Hours are the most negotiated part of a consent. Ask the authority for its standard hours rather than assuming them, because they vary and a consent that contradicts a planning condition on hours creates a conflict you have to resolve later.

Out of hours working needs to be identified in the application, not requested afterwards. The activities that really need it are limited and recognisable: continuous concrete pours that cannot be interrupted, crane lifts requiring a road closure, work in a rail possession, deliveries of abnormal loads escorted at night, and utility diversions during off-peak periods.

For each, give the date window, the duration, the receptors affected, the mitigation and the notification arrangement. A consent that permits named activities outside normal hours, with a letter drop to affected residents 48 hours beforehand, is much easier to defend than a general permission to work late. Evening and night servicing raise the same issues once the building is occupied, and night deliveries and servicing noise are assessed on a different basis again.

How it interacts with planning conditions

The two regimes run in parallel and neither overrides the other.

A section 61 consent does not displace a planning condition restricting hours. If the condition says 08:00 to 18:00 and the consent permits a night pour, you need a variation of the condition as well. Equally a planning condition approving a construction management plan does not prevent a section 60 notice, because the protection in section 65 only follows from a section 61 consent.

So the tidy arrangement is a planning condition on hours that matches the consent, a construction management plan that cross-references it, and the consent itself carrying the detail. Where a complaint is made after occupation the statutory nuisance route remains open to residents regardless of either document.

Variations when the programme changes

Programmes change, and a consent obtained for a method you no longer intend to use is worse than no consent, because carrying out works in contravention of a consent is an offence.

Apply to vary whenever any of four things change: the plant, the method for a noisy activity, the hours, or the duration of a noisy phase in a way that materially extends exposure. A variation is quicker than a fresh application and the authority is dealing with a document it already knows.

Illustrative example: a city centre basement scheme consented for contiguous flight auger piling within stated hours, with vibration monitoring on two adjoining party walls. Ground conditions required a change to cased augering with a heavier rig. The contractor applied to vary, supplied revised predictions and an additional monitor, and the variation was issued in under three weeks. Work continued. Had the rig simply arrived, the authority's first step would have been a section 60 notice on its own terms.

Enforcement and the appeal route

Failure to comply with a section 60 notice, or knowingly carrying out works in contravention of a section 61 consent, is a criminal offence. Enforcement sits with environmental health rather than with planning.

There is an appeal to the magistrates' court against a section 60 notice, and against a refusal or the conditions attached to a section 61 consent, within 21 days. The deadline is short and the court is not a planning tribunal, so the grounds have to be framed around the Act rather than around fairness.

Two habits reduce the risk of ever getting there. Monitor as you promised and keep the records, because a trigger exceedance you recorded and acted on reads very differently from one a resident recorded for you. And answer complaints within a day, in writing, with what you did.

Draft your noise impact assessment on PlanScope and send it to an acoustician for review before the section 61 application goes in.

This is general guidance, not legal advice. Construction noise assessment needs a suitably qualified acoustician, and threshold values and procedures should be taken from the current standard. Check the position with your local authority before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.