How to work out your capacity for Martyn's Law

Section 2 of the Act says premises are covered if it is reasonable to expect that, from time to time, 200 or more people may be present at the same time in connection with a listed use. Premises where 800 or more can reasonably be expected are enhanced tier, unless they are one of the four kinds that are standard tier at any size. The Home Office has published a supplementary document, known as Supplementary Document A, explaining how to assess this figure. Each part of the test matters.

At the same time

The figure is the number of people present together at any one moment, not the total who pass through in a day. A shop, museum or leisure centre with steady turnover may have far fewer people inside at once than its daily visitor numbers suggest.

From time to time

"From time to time" means occasionally. It is not an average over a day or a week. Busy periods that you can reasonably expect to come round again, such as weekends, festivals, the weeks before Christmas or an annual event, count. A one-off peak that could not reasonably be anticipated to happen again does not bring premises into scope.

External events can matter too. The Home Office mentions major televised sports events as an example: if you can reasonably expect similar crowds next time, that figure counts.

Including staff and volunteers

Staff must be included in the final figure under every method. That means employees, contractors and volunteers present in connection with the listed use, as well as customers, worshippers, members, pupils or spectators.

Only the part used for a listed use

Only people in the part of the premises used for a listed use are counted. People in the immediate vicinity, such as a queue on the pavement, are not counted in the figure, although your procedures should still take account of them.

Supplementary Document A sets out six methods, labelled A to F. You can use whichever best reflects how your premises are actually used. The worked examples for methods A to E below are the Home Office's own; the Home Office gives no worked example for method F.

Method A: safe occupancy for fire safety purposes

This is the maximum number that can be safely accommodated in the building for fire safety purposes, usually found in your fire risk assessment. It is the right method where your premises are often full. In the Home Office example, a café with a safe occupancy of 250, including staff, which is often full, is assessed at 250 and is standard tier. In a second example, a café with an indoor occupancy of 180 and 30 outdoor seats, often full, is assessed at 210, which shows that outdoor areas forming part of the premises count.

Method B: historic attendance data

This uses your own records from previous years, reflecting actual use at peak times. It suits premises that are rarely near their fire safety figure. In the Home Office example, a nightclub with a safe occupancy of 875 peaked at 725, including staff, over twelve months, and is standard tier; the guidance adds that it should review the figure before higher-demand nights such as themed events. In another, a stately home that received 850 visitors in a day, but never more than 300 at once once arrival times and length of stay were considered, is standard tier.

Historic data has a limit. The Home Office notes it is not always a reliable predictor of the future, so it should be reviewed regularly. In a third example, a hotel whose annual event reached 900 people at one point is enhanced tier, because the event recurs.

Method C: fixed seating or fixed standing positions

This uses the number of fixed seats or standing positions, plus staff. It suits theatres, cinemas, restaurants with fixed seating, and places of worship with pews. In the Home Office example, a restaurant with 450 fixed seats and 30 staff, full at peak times, is assessed at 480 and is standard tier.

Method D: tickets and pre-registration

This uses the maximum number of tickets issued or registrations taken, plus staff. It suits ticketed or booked events. In the Home Office example, a music event in a field with 300 pre-sale and 600 general-sale tickets, plus 300 staff, is assessed at 1,200, making it a qualifying event with enhanced duties.

Method E: restrictions on numbers

This uses a limit imposed on the premises or event, such as a figure attached to a premises licence, provided the limit is actually kept to. In one Home Office example, a museum exhibition with timed entry limiting attendance to 750 at any one time is not a qualifying event, and the museum remains standard tier. In another, a nightclub with a licence limit of 975, monitored with a people counter, plus staff, is enhanced tier. Remember to add staff if the limit does not already include them.

Method F: other means of assessing

Where methods A to E are not appropriate, you may use another method if you can justify it with supporting evidence and explain how the figure was calculated and why it is reasonable. The Home Office says the figure and its assumptions should be reviewed regularly. As our own illustration (not a Home Office example), a new venue with no attendance history might use projected figures from its business plan, with the assumptions recorded and reviewed once real data is available.

The Act covers a building, part of a building or a group of buildings, with any land that goes with them. If only part of a building is used for a listed purpose, only that part is assessed. The Home Office example is a factory with a shop attached: the factory is not a listed use, so only the shop's customers and staff are counted against the thresholds.

Equally, a group of buildings used together can be assessed as one set of premises. The Home Office example is a hospital spread across fourteen buildings, assessed as a single group. Where the same person is responsible for premises that form part of other premises, they are treated as one set of qualifying premises.

If your figure sits close to a threshold, be careful and be honest. Choose the method that best reflects your busiest regular period, write down your reasoning, and review it whenever your trade or events change.

Do not choose a method simply because it gives a lower number. If your fire safety occupancy is 260 and you are regularly full, using a quieter month's attendance records to reach 190 would be hard to justify as a reasonable expectation. The figure should be one you would be comfortable explaining to the SIA with your records in front of you.

Places of worship, nurseries and other childcare settings, primary and secondary schools, and further education colleges are standard tier at any number of 200 or more. For them, the 800 line does not matter, and events held on their premises cannot be qualifying events. They still need to work out whether they reach 200, counting worshippers or pupils together with staff and volunteers; our guide to churches and places of worship covers congregations. Universities and other higher education institutions do not get this treatment.

The SIA can ask for information about how you assessed your numbers, so keep a clear record. It should state the figure, the method you used, the evidence behind it, why that method suits your premises, who made the assessment and when. A capacity assessment record does exactly this, and is one of the ten documents in our pack.

Review the record at least once a year, and whenever something changes: an extension, a new licence, a change in opening hours, a new regular event or a change in how the building is used. If the change takes you into or out of scope, or between tiers, you may need to update the information you have given to the SIA. Our responsible person and SIA notification record keeps track of this.

1. 01Choose the method that best fits your premises and how they are used.
2. 02Work out your figure for your busiest regular period, including staff, contractors and volunteers.
3. 03Write down the figure, the method, the evidence and your reasoning.
4. 04If you are at 200 or more, confirm who the responsible person is and start on your four procedures. Our sector guides for pubs and bars, village halls, sports clubs and shops explain what that involves.
5. 05Review the figure every year and whenever your use changes.

Our Standard Tier Pack records your capacity assessment and builds your procedures, briefing sheet and poster from your answers, from £79 a year. See pricing. It is a set of templates to review and adopt, not legal advice.

For the wider picture, read Martyn's Law explained and the full list of covered buildings.