Private amenity space standards and how councils measure them

There is no national minimum for private garden or balcony size in England, so private amenity space standards come from the adopted local plan and its supporting design guidance, and they differ by authority. What is consistent is how officers measure the space: usable area only, directly accessible from the dwelling, meeting a minimum dimension, and excluding the strips of land that exist for bins, metering and access. A scheme that meets the headline area figure but fails on shape or accessibility will still be reported as a shortfall.

Where amenity space standards come from

The Nationally Described Space Standard deals with internal floor area and built-in storage, and it says nothing about outdoor space. It is also an optional technical standard, applying only where an authority has adopted it through a local plan policy with the necessary viability evidence.

Outdoor amenity standards sit one level down, usually in a residential design guide or a housing supplementary planning document. Because they are local, the first task on any site is to read the actual policy wording rather than the summary, and to check whether the document is adopted or draft. Weight differs.

In London, the London Plan sets a floor. Its housing quality and standards policy requires a minimum of 5 m² of private outdoor space for one and two person dwellings, with a further 1 m² for each additional occupant, and a minimum depth and width of 1.5 metres. Boroughs then apply their own, often higher, figures for houses and for communal provision.

Private, communal and shared space definitions

The three terms get used loosely and they mean different things in a policy test.

A roof terrace serving one flat is private space. The same terrace serving six flats is communal. A landscaped strip alongside a car park that nobody can sit in is neither, whatever the area schedule says.

How usable area is measured

Officers discount space that cannot be used, and the discounting is where area schedules lose ten or fifteen per cent. Expect the following to come off.

• Land narrower than the minimum dimension in the policy, typically 1.5 metres, including the tapering ends of irregular gardens.
• Access paths to a bin store, cycle store or metering cupboard that has to be crossed by other residents.
• Bin and cycle store footprints themselves.
• Land in front of the building line, which is generally treated as setting rather than amenity.
• Steeply sloping ground, retaining structures and areas within a required root protection area where the surface cannot be used.
• Land in deep permanent shade, which is a quality judgement rather than a fixed rule.

Set out the calculation in a table per unit type, with a plan showing the counted area hatched. That single drawing removes most of the argument, and it makes the shortfall discussion, if there is one, an honest conversation about specific units rather than a dispute about arithmetic.

Balcony minimum dimensions and depth

Depth matters more than area. And a balcony 1 metre deep and 5 metres long has the same area as one 2 metres by 2.5 metres, and it is close to useless because a table and two chairs will not fit. Most policies therefore set a minimum dimension alongside the area figure, and 1.5 metres is the common figure.

Practical points that come up at committee:

1. Door thresholds should be level for accessible units, which affects the structural build-up and the depth available.
2. Balustrade design affects privacy and overlooking, and obscured glazing to the sides is often conditioned.
3. Balconies on higher floors in exposed locations can be unusable in wind, which is why a Wind Microclimate Assessment is asked for on taller schemes.
4. Inset balconies reduce daylight to the room behind, so the amenity gain has a daylight cost that shows up in the assessment.

That last point is the trade-off that catches design teams. A deep inset balcony in front of a living room window can push the room below the daylight targets used in a Daylight and Sunlight Assessment, and the fix, moving to a projecting balcony, may not sit well with the elevation or the fire strategy.

Child play space alongside amenity space

Play space is a separate requirement and it is not satisfied by counting gardens. In London, the London Plan requires 10 m² of playable space per child, with the child yield calculated from the proposed unit mix using the published population yield methodology, and provision expected on schemes above a threshold size.

Outside London, standards vary widely and many authorities apply a fields in trust style standard through their open space policy. Where provision cannot be made on site, a financial contribution is usually sought through a section 106 obligation, and the calculation should be checked against the council's published formula.

Doorstep play for under fives has to be within sight of homes and close to entrances, which is a layout decision rather than a landscape one. Design it in at the massing stage. A Play Space Assessment then documents the yield calculation, the provision by age group and the distances, which is what an officer needs to write the report.

Sites where standards cannot be met

Constrained urban sites, conversions and listed buildings cannot always deliver the numbers. Policies usually recognise this, and the way to handle it is to state the shortfall plainly, quantify it, and set out what compensates.

Arguments that carry weight include larger internal floor areas than the minimum, dual aspect layouts, generous communal space of good quality, direct proximity to a park with a stated walking distance, and a winter garden that provides usable outdoor space where an open balcony is not possible on noise or wind grounds.

Arguments that do not carry weight: a nearby public footpath, a shared surface that is really a car park, and a landscaped area that residents cannot reach without leaving the building.

An illustrative example: a conversion of a three storey commercial building into eight flats on a tight urban plot, with no scope for private balconies to the street elevation. Six units get 1.6 metre deep rear balconies, two get none, and a 90 m² communal roof terrace with planting, seating and a level threshold from the top floor lobby serves the whole building. The area schedule shows the shortfall for the two units and the compensating provision beside it. This example is illustrative only.

Arguing a shortfall with compensating quality

Officers weigh what is in front of them. Three things make the case easier to accept: honest measurement, a drawing that shows exactly what is being counted, and a clear statement of what the residents of each unit actually get. Where the shortfall falls on a small number of units, say which ones and why.

Where compensating measures are offered, secure them. A communal roof terrace shown on a plan but not conditioned or managed can disappear at technical design stage, and officers know it. Offer a management arrangement, and set out maintenance responsibility in the Design and Access Statement so the commitment is on the record.

This is general guidance, not legal advice, and amenity space standards are set locally, so check the adopted local plan and any design supplementary planning document with your local planning 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.