Documents for a scheme of exactly ten dwellings
Ten units is the line between minor and major development in England. The submission, the timetable and the obligations all change on the day you cross it.
Ten dwellings is the point at which a residential scheme becomes major development in England, and almost everything about the application changes with it. The determination period goes from eight weeks to 13. The fee moves into a different band. Affordable housing policy usually bites. Biodiversity net gain follows the majors regime rather than the small sites route. If your site plan shows nine units, adding the tenth is a decision about process as much as about yield.
Nine units and ten units are not a small difference. They are two different applications.
Why the tenth unit changes the submission
Major development for housing is defined in the Town and Country Planning (Development Management Procedure) (England) Order 2015 as 10 or more dwellings, or a site area of 0.5 hectares or more where the number is not known. The second limb catches outline applications with no fixed unit count, so a 0.6 hectare outline for housing is major even if you expect eight houses.
The consequences are procedural and substantive at once. Publicity requirements step up, the application is more likely to go to committee, and the policy framework that applies to majors in your local plan switches on.
PlanScope's own recommendation engine uses 10 or more units, 1,000m² or more of floorspace, or 0.5 hectares or more as the thresholds that flag a scheme as major. Those mirror the national definition, though your council's validation list and the adopted local plan take precedence over any tool.
The determination period and the publicity that goes with it
A major application carries a statutory determination period of 13 weeks from validation, against eight weeks for a minor. Where the development is EIA development the period is 16 weeks.
That extra five weeks is not spare time. It is roughly what the consultation and consultee response cycle needs on a scheme of this size, and most authorities will still ask for an extension of time agreement before the expiry date.
Publicity moves from neighbour notification alone to a site notice or newspaper advertisement, depending on the authority's adopted practice and whether the proposal affects a heritage asset or departs from the development plan.
Affordable housing at the threshold
National policy sets the general position that affordable housing contributions should not be sought from developments of fewer than 10 homes, with lower thresholds available in designated rural areas. At exactly 10 you are inside the net.
What the council can ask for comes from the adopted local plan, which will state a percentage, a tenure split and whether on-site provision or a commuted sum is expected. Read the policy as adopted rather than the emerging version, then check whether a supplementary planning document sets out the calculation.
An Affordable Housing Statement should set out the unit count, the habitable rooms or floorspace basis the policy uses, the proposed tenure mix, the registered provider position if you have one, and the delivery mechanism through a section 106 agreement. Where you are arguing that the policy requirement makes the scheme unviable, that is a separate viability case with its own evidence, and it needs to be flagged early rather than at committee.
Splitting a site into two applications of five units each to avoid the threshold is a recognised approach that councils treat as a single planning unit where the land and the applicant are the same. Expect it to be tested.
Biodiversity net gain for a major scheme
Mandatory biodiversity net gain under the Environment Act 2021 applied to major development from 12 February 2024 and to small sites from 2 April 2024. At 10 units you are in the major regime, which means no small sites metric and no reduced information requirement.
In practice the pack needs a habitat baseline survey carried out at the right time of year, the statutory metric completed, and a biodiversity gain plan for approval after permission is granted under the pre-commencement biodiversity gain condition. The 10 per cent uplift must be maintained for 30 years, secured by planning obligation or conservation covenant.
The statutory metric is expected to be completed by a competent person, so a Biodiversity Net Gain Assessment drafted at the outset is a starting point for that professional rather than a substitute for them. Habitat condition assessment in particular needs a qualified ecologist on site.
Timing is the thing that catches self-builders. Botanical survey work is best between April and September, so a December start on a site with grassland habitat means waiting.
Drainage and flood evidence at this scale
A site of one hectare or more needs a Flood Risk Assessment regardless of flood zone, and any site in Flood Zone 2 or 3 needs one whatever its area. A ten-unit scheme on 0.4 hectares in Flood Zone 1 may not need a full assessment, though the lead local flood authority will still expect a surface water drainage strategy.
Majors are a statutory consultation for the lead local flood authority on surface water drainage, which means a Drainage Strategy with greenfield run-off rates, attenuation volumes, infiltration testing results where infiltration is proposed, and a maintenance plan. Get the infiltration tests done before you fix the layout, because a failed percolation test can move the attenuation basin and lose you a plot.
Foul drainage capacity is a separate question. The sewerage undertaker will comment on connection, and on a site of this size a capacity check is worth doing before submission rather than in response to a holding objection.
Transport evidence below the assessment threshold
Ten dwellings sits well below the point at which a full Transport Assessment is normally required. The threshold PlanScope uses to flag one is 50 or more units or 2,500m² or more, which reflects common practice rather than a national rule.
What the highway authority will want is a Transport Statement covering access geometry, visibility splays, trip generation, parking provision against the adopted standard and refuse vehicle tracking. On an estate road that will be offered for adoption, the section 38 position should be explained even though the agreement itself comes later.
Construction traffic is the other item. Many authorities now condition a construction management plan on majors as a matter of course, and offering one with the application removes a pre-commencement condition from the critical path.
The pack in the order you should commission it
- Site survey, topographical and tree survey to BS 5837:2012, because the layout depends on them.
- Preliminary ecological appraisal and habitat baseline for the metric, booked around the survey season.
- Ground investigation and infiltration testing, which set finished floor levels and the drainage approach.
- Layout and house types, then the drainage strategy and transport statement against the fixed layout.
- Planning Statement, Design and Access Statement, Affordable Housing Statement and the biodiversity documents.
- Pre-application advice at the point where the layout is fixed but not yet drawn up in detail.
A Design and Access Statement is required for major development, and a Planning Statement carries the policy case. Check the council's local validation list before submission, because the items beyond the national requirements vary and a missing one costs you weeks at the validation stage.
Enter your postcode on PlanScope to see which of the 66 reports a ten-unit site is likely to need.
This is general guidance rather than 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. For specialist technical reports, qualified professional input may be required.
Frequently asked questions
Is ten dwellings always major development?
For housing, yes. The Development Management Procedure Order 2015 defines major development as 10 or more dwellings, or a site of 0.5 hectares or more where the number is not yet known. An outline application on 0.6 hectares is therefore major even if the indicative layout shows eight houses, because the area limb applies.
Can I split a ten-unit site into two applications of five?
You can submit them, but councils routinely assess whether the land forms a single planning unit under common ownership and control. Where it does, the affordable housing and biodiversity requirements are usually applied to the whole. Expect the approach to be tested at validation and again at committee, and budget for the delay if it is refused.
Does biodiversity net gain apply differently at ten units?
Yes. Small sites rules, including the small sites metric, apply below 10 dwellings and below 0.5 hectares. At ten units you use the full statutory biodiversity metric, with a habitat baseline survey and a biodiversity gain plan submitted for approval after permission under the pre-commencement gain condition.
Will I need a Transport Assessment for ten homes?
Usually not. Ten dwellings generates modest trip numbers and a Transport Statement covering access, visibility, parking and refuse tracking is normally enough. A full assessment tends to be triggered around 50 units or 2,500 square metres, or where the access is onto a constrained or sensitive road. Ask the highway authority at pre-application stage.
How long will the council take to decide?
The statutory period for a major application is 13 weeks from validation, or 16 weeks for EIA development, against eight weeks for a minor. Most authorities ask for an extension of time agreement before expiry on schemes of this size. Treat the statutory period as the earliest realistic date rather than the expected one.
Sources and further reading
This article is general guidance about the planning system in England and, where stated, the rest of the UK. It is not legal or professional advice. Check your local planning authority’s validation requirements and take professional advice for your specific site.