Reports for a nine dwelling scheme below the major threshold

Nine dwelling planning reports look deceptively similar to a ten dwelling pack, and the difference in cost is real. Staying at nine keeps the scheme out of major development, which shortens the determination period from 13 weeks to eight, removes the affordable housing requirement in most authorities, and drops several documents off the validation list. What it does not do is remove biodiversity net gain, drainage evidence or the highway authority's interest.

There is also a trap in the definition. Nine dwellings is not automatically minor development, and the site area can push you into the major category whatever the unit count says.

What staying below ten units avoids

The definition of major development sits in the Development Management Procedure Order 2015. For housing, it captures schemes of 10 or more dwellings, and it captures schemes on sites of 0.5 hectares or more where the number of dwellings is not yet known, which is the outline application case. It also captures any development on a site of 1 hectare or more, regardless of what is being built.

So a scheme of nine houses on a 0.6 hectare site, with the unit count fixed, is minor. The same nine houses on a 1.1 hectare site is major, because of the site area limb. Check the red line area before you plan the strategy around the unit count.

Where the scheme is properly minor, these follow:

• An eight-week statutory determination period rather than 13
• No affordable housing contribution in most authorities, since national policy sets the threshold at major development
• No requirement for a statement of community involvement under the thresholds PlanScope uses to flag reports, which sit at 50 units
• Lighter publicity requirements, generally site notice or neighbour letters rather than press advertisement
• A materially lower application fee

Councils' own validation lists take precedence over any general rule here, and several authorities require documents at nine units that others do not ask for until fifty.

The documents still required at this scale

Start with the ones that apply to any application for new dwellings.

A Planning Statement establishing the principle of development against the adopted local plan, the settlement boundary, the housing land supply position and the character of the area. At nine units this is a real document rather than a formality, because the scheme is large enough to change a street and small enough that design will be the main issue.

A Design and Access Statement is required where the development is major, or where it is in a conservation area or World Heritage Site and involves one or more dwellings. A nine-unit scheme outside those designations does not need one as a national requirement, though many councils ask for one locally and most schemes at this scale benefit from having one.

Then drawings: location plan, site plan showing levels and boundary treatment, floor plans and elevations for each house type, street scene elevations, and a landscape or planting plan.

Transport evidence for a minor scheme

Nine dwellings will not trigger a full Transport Assessment in most authorities. The thresholds PlanScope uses flag a transport assessment at 50 or more dwellings or 2,500 m2 of floorspace, and national practice guidance expects the scope to be agreed with the highway authority rather than fixed by a national number.

What you will need is a Transport Statement or a transport note covering access geometry, visibility splays measured to the local standard, parking provision against the adopted parking standard, refuse vehicle access and swept paths, and a short trip generation estimate.

The swept path drawing is the one that gets forgotten. A nine-house cul-de-sac that a refuse vehicle cannot turn in will be objected to by the highway authority and the waste team separately, and the fix is usually a wider turning head, which costs a plot.

Drainage and flood risk at under one hectare

A site below 1 hectare and outside Flood Zones 2 and 3 does not need a full Flood Risk Assessment, though surface water flood risk and any local critical drainage area will still be checked.

A drainage strategy is a different matter, and at nine units you will need one. Infiltration testing to establish whether soakaways work, attenuation sizing where they do not, a restricted discharge rate if connecting to a sewer or watercourse, and exceedance routing for events beyond the design standard.

Get the infiltration testing done before the layout is fixed. Where the ground turns out to be clay, attenuation storage has to go somewhere, and finding that space after the plots are laid out usually costs a unit.

Ecology and biodiversity net gain

This is the requirement that does not respect the major threshold.

Mandatory biodiversity net gain applies to small sites in England from 2 April 2024. A nine-dwelling scheme on a site under 1 hectare is a small site, which means the small sites metric can be used, but the ten per cent gain, the biodiversity gain plan and the 30-year maintenance obligation all still apply.

Exemptions exist. The self-build and custom build exemption covers developments of no more than nine dwellings on sites of no more than 0.5 hectares where every dwelling is self-build or custom build, which is worth checking if the scheme is being sold as serviced plots. The de minimis exemption applies below 25 m2 of onsite habitat and 5 m of linear habitat, which almost no nine-unit scheme meets.

Budget for a Preliminary Ecological Appraisal as well. It establishes the habitat baseline the metric needs and flags whether protected species surveys are required, and those surveys have seasons. A bat emergence survey cannot be done in January, and discovering that in November costs a spring.

Affordable housing at this scale

National policy sets the affordable housing threshold at major development, so a nine-unit scheme in most authorities carries no affordable housing obligation.

The exception matters. In designated rural areas, authorities may set a lower threshold of five units or fewer, and where they do, a nine-unit scheme is caught. Check the adopted local plan before assuming the scheme is clear, particularly in National Landscapes and in parishes designated under the rural exception provisions.

Be careful about subdivision too. Bringing forward nine units now and a further phase later, on land in the same ownership, invites an argument that the scheme has been artificially split. Councils look at this, and inspectors look at it on appeal.

Budgeting the evidence base

Order the work in the sequence that lets each piece inform the next: ecological appraisal and infiltration testing first, because both can change the layout. Then the topographic survey and tree survey. Then the drainage strategy and transport note against a settled layout, and the planning statement last, once the design is fixed.

Commissioning the planning statement first, which happens often, produces a document written against a scheme that then changes.

For a comparable scheme on previously developed land, where contamination and demolition evidence enter the picture, our companion piece on reports for a nine-unit scheme on a brownfield site sets out what changes.

PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval. For specialist technical reports, qualified professional input may be required, and the biodiversity metric must be completed by a competent person.

This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it.