Bin store sizing worked example for a flat conversion

Bin store sizing for flats is arithmetic driven by a local standard, and the standard is almost never in the local plan. It sits in the council's waste service pages or a supplementary planning document, expressed as litres of capacity per flat per week by waste stream. Find that figure first. Everything else, including whether the conversion works at all, follows from it.

On a two storey terrace converted into four flats, the store is frequently the thing that fixes the unit count. A yard that takes two large containers and a path takes four flats. A yard that takes one takes three.

Finding the standard that applies

Ask the council's waste team directly, in writing, and ask four questions at once.

What capacity per dwelling per week do you require for each waste stream. What container sizes do you supply, and will you supply them to a conversion. What is your collection frequency for each stream. And what is your maximum drag distance from the store to the point where the vehicle stops.

The answers vary considerably between authorities, and some publish them clearly while others hold them only in a service document the planning officer will quote at you later. Get the reply in writing and attach it to the application. An officer who can see the waste team's own figures in your submission has nothing left to query.

Approved Document H to the Building Regulations provides the national backstop, covering storage capacity and the distances over which containers should be moved. It is the floor rather than the standard, since planning authorities routinely require more, and where the two differ the more onerous applies.

Container sizes and the arithmetic

Containers come in a small number of standard sizes, and the design has to use the ones your authority actually supplies.

The calculation is straightforward once the standard is known. Multiply the number of dwellings by the required capacity per dwelling per week, multiply by the number of weeks between collections for that stream, then divide by the container size and round up. Do it separately for each stream, because collection frequencies differ.

The rounding up is where space is lost. A requirement of 960 litres needs a 1,100 litre bin, and so does a requirement of 1,150 litres plus a second one. Where the figure sits just above a container size, ask whether a slightly reduced provision or a different container combination is acceptable before redesigning the yard.

An illustrative worked calculation

The figures below are illustrative only. They are not any authority's published standard, and you must substitute your own council's figures before using the method.

Assume a conversion of one house into four flats, with an authority standard of 120 litres of residual capacity and 120 litres of recycling capacity per flat per week, residual and recycling both collected fortnightly, and food waste collected weekly with a 23 litre internal caddy per flat.

1. Residual: 4 flats multiplied by 120 litres, multiplied by 2 weeks, gives 960 litres. One 1,100 litre container.
2. Recycling: the same arithmetic gives 960 litres. One 1,100 litre container.
3. Food waste: 4 caddies at 23 litres, collected weekly, gives 92 litres. One 140 litre container.

So the store holds two 1,100 litre containers and one 140 litre bin. Now the footprint. A 1,100 litre container occupies roughly 1.3m by 1.1m on plan and stands about 1.45m high, though dimensions differ between manufacturers, so confirm the sizes your authority uses.

Allow a small gap between containers, around 150mm, and a clear area in front deep enough to pull a container out and turn it, which in practice means at least a metre. That gives an internal store of roughly 3.2m by 2.1m for this example, plus the door.

Compare that to the yard you have. On a Victorian terrace with a 3m wide rear yard, the store runs across the full width and leaves a side passage of nothing. That is the point at which the scheme changes rather than the store.

Drag distance and collection vehicle access

The crew pulls the containers to the vehicle, and the distance they will pull them is an operational limit set by the waste service rather than by planning policy.

Approved Document H gives the national guidance on how far containers should be moved, and local services often work to shorter distances for the larger containers, because a loaded 1,100 litre bin is heavy and awkward on a slope or over a kerb. Measure the route, not the straight line. A store at the back of a plot with access only through the building is almost never accepted for communal containers.

Three things to check on the route. Surface, which needs to be hard, smooth and level, since gravel and cobbles are refused. Gradient, because a slope on the drag route is a manual handling objection. And width, including the clear opening of any gate, which has to take the widest container without the crew lifting it.

Then check the vehicle. Refuse vehicles need a stopping point within the drag distance, and where a street is narrow or has no turning head, the waste authority may decline to enter it at all. Ask the question for the specific street rather than assuming, because an authority that will not reverse more than a short distance effectively dictates where the store goes.

Recycling, food and bulky waste

Four streams need thinking about, and applications regularly provide for two.

Dry recycling needs the same treatment as residual, sometimes with separate containers for different materials depending on the authority's collection method. Food waste needs a container with a secure lid, close to the exit, and a position that will not become a nuisance in summer. Garden waste may be a subscription service with its own container, which still needs somewhere to stand.

Bulky waste is the forgotten one. Flat conversions generate mattresses and furniture at every tenancy change, and with no provision they end up in the yard or on the pavement. A small area within or beside the store, shown on the plan and referenced in the management arrangements, answers the officer's question before it is asked.

Where recycling provision across a larger scheme has to be demonstrated, a Waste Management Strategy sets out the streams, the capacities and the operational arrangements in the form authorities expect.

Designing the store itself

A store that works is ventilated, cleanable, lockable and visually discreet.

Provide cross ventilation at high and low level, usually through slatted sides or vents, so the store does not become anaerobic. Lay a solid floor falling to a drainage point or to the outside, so it can be hosed down. Fit a door wide enough for the largest container with the lid closed, opening outwards, with a level or ramped threshold rather than a step. Provide a lock the crew can operate, which usually means a latch rather than a padlock, and agree the arrangement with the waste service.

Then deal with appearance. A brick-built store with a tiled or green roof reads as part of the building. A plywood box does not, and in a conservation area it will attract a condition requiring details. Where the store sits in a front garden, which is common on terraces with no rear access, expect the design to be the main point of discussion and treat it accordingly in the Design and Access Statement.

Drawing conventions the officer expects

Produce one drawing that answers the whole question.

Show the store on the block plan and at a larger scale, with each container drawn to size and labelled with its capacity. Dimension the internal store, the door opening and the clear area in front. Dimension the drag route from the store door to the collection point on the highway, and annotate the surface and the gradient. Add a short note giving the authority's standard, the calculation and the resulting container schedule.

That note is what makes the drawing self-explanatory. A store shown as a hatched rectangle labelled "bin store" is the version that generates a request for further information. The same approach applies to other standards-driven calculations, and our note on cycle parking calculated from the policy standard follows the same pattern.

Where the standard cannot be met

Sometimes the yard will not take it, and the honest options are limited.

Reduce the number of flats until the provision fits, which is the answer most often reached. Negotiate a different container combination with the waste service, for example three 660 litre bins instead of two 1,100 litre bins, which can fit a narrower space. Ask whether the authority will accept a higher collection frequency with smaller containers, which some will for a small number of units. Or propose on-street communal provision, which requires the highway authority's agreement and usually a contribution, and is rarely available.

What does not work is timed presentation by the occupiers, a store accessed through a flat, or a provision that relies on residents taking bins through a communal hallway. Officers have seen all three and will refuse them.

Ask the waste team for their figures before you draw anything. On a flat conversion, that single email often decides the unit count.

This is general guidance, not legal advice. Check the position with your local planning authority or a qualified professional 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.