Reserved matters on a self-build plot with outline consent

Outline consent settles the principle of a house on your plot. It settles almost nothing else. The reserved matters reports self build applicants need are the ones that answer the matters the outline deliberately left open, plus the reports that discharge the conditions attached to it, and those are two separate applications with two separate fees.

Get the sequence right and a serviced plot moves from outline to a start on site in a few months. Get it wrong, in particular on the Community Infrastructure Levy, and it costs money that cannot be recovered.

What the outline settled and what it left open

An outline permission establishes that development of the described type is acceptable in principle at that location. The reserved matters are defined in the Development Management Procedure Order 2015 as access, appearance, landscaping, layout and scale, and the outline decision notice says which of them were reserved.

Read the notice carefully. Some outlines fix parameters, such as a maximum ridge height, a building zone or a number of units, and a reserved matters application cannot depart from them. If your design needs to, the route is a fresh application or a variation under section 73, not a reserved matters submission the officer is expected to stretch.

Time limits matter as much as content. The default position under section 92 of the Town and Country Planning Act 1990 is that the reserved matters application must be made within three years of the outline permission, and the development must begin within two years of the final approval of the last reserved matter. The decision notice can set different periods, so check it rather than assuming the default.

The reserved matters submission

This application is about detail, and the officer is checking consistency with the outline rather than reopening the principle.

For a single plot, the submission usually comprises:

• Site layout at 1:200 or 1:100 showing the dwelling, parking, turning, bin and cycle storage and the private garden.
• Floor plans and elevations at 1:100 with materials annotated.
• A street scene or contextual elevation showing the neighbouring properties.
• Existing and proposed levels, including finished floor level and any retaining structures.
• A hard and soft landscaping plan with a planting schedule giving species, sizes and numbers.
• Boundary treatment details.
• A materials schedule naming products rather than describing colours.

A Design and Access Statement is required where the outline was major development or the site is in a conservation area, and it is worth providing in any event to explain how the design responds to the parameters set at outline.

Levels are the item most often left thin and most often queried. On a sloping plot, a section through the site showing existing ground, proposed ground and finished floor level against the neighbouring boundary answers the overlooking and overbearing questions before they are asked.

Pre-commencement conditions and the reports that discharge them

The outline decision notice will carry conditions, and the pre-commencement ones control when you can start.

Typical examples on a single self-build plot include contaminated land investigation, surface water drainage details, a construction method statement, tree protection to BS 5837:2012, archaeological evaluation where the site sits in a sensitive area, and details of external materials.

Each is discharged by an application to the council under the relevant procedure, with a fee per request and an eight-week determination period. Bundle them into one submission where you can, and do not start work on anything that counts as a material operation until the pre-commencement conditions are formally discharged. Starting first does not simply delay approval, it can render the permission unimplemented.

Drainage is the condition that most often causes a delay on serviced plots. If the outline assumed a soakaway, percolation testing to the relevant standard has to be done and the results submitted. Tests carried out in a dry August on clay can produce a result that will not be accepted, so plan the timing.

Where a drainage strategy has to be prepared from scratch, a Drainage Strategy sets out the discharge hierarchy, the calculations and the maintenance arrangements the council will want to see.

The CIL self-build exemption and its timing traps

This is where self-builders lose money, and the rules are unforgiving because they are procedural rather than discretionary.

1. Submit an assumption of liability notice before commencement.
2. Submit the self-build exemption claim and have it granted by the charging authority before commencement.
3. Submit a commencement notice, and do it before any work starts on site.
4. After completion, submit the supporting evidence within the period the regulations allow, which includes proof of title, a completion certificate or warranty, and evidence that you occupy the dwelling as your principal residence.
5. Keep occupying it as your main home for the three years following completion, because a disposal within that period triggers a clawback of the levy.

The commencement notice is the trap. Miss it, or file it after the first material operation, and the exemption is lost entirely regardless of everything else you did correctly. Councils have very little discretion here.

Check whether the levy applies at all before you plan around the exemption. Not every authority charges the levy, rates vary by area and use, and a plot may also carry a section 106 obligation from the original outline permission that binds the land whoever owns it.

Ecology, drainage and evidence carried over

Work done at outline stage does not always survive to reserved matters, and the shelf life of survey data is the thing to check.

Ecological survey data ages. Where a preliminary ecological appraisal was done three years before your reserved matters application, the council or its ecologist may ask for an update walkover, and any protected species survey has to fall within the right season. Any survey or licence work involving bats, newts or badgers must be carried out by a suitably licensed ecologist.

Biodiversity net gain depends on when the outline application was made rather than when it was decided. Where the biodiversity gain condition applies to your permission, a biodiversity gain plan has to be approved before development begins, and on outline permissions it is normally handled in phases. A Biodiversity Net Gain Assessment sets the baseline and post-development values, with the statutory metric completed by a competent person.

Flood and drainage evidence usually carries over unchanged unless the mapping has been updated. Check the current flood map for the site before submitting, since a change in the published zone between outline and reserved matters is not something you want the case officer to notice first.

Illustrative document schedule for a single plot

This example is illustrative. A serviced plot with outline consent for one dwelling, all matters reserved, would typically need:

1. Reserved matters application with layout, plans, elevations, sections, levels, landscaping and boundary details.
2. Design and access statement where required by the outline.
3. Discharge of conditions application covering drainage, materials, tree protection and any construction method statement.
4. Percolation test results or a drainage strategy.
5. Ecology update where the original survey has aged, plus the biodiversity gain plan where the condition applies.
6. CIL assumption of liability, exemption claim and commencement notice, in that order and all before starting.

Set the CIL paperwork against the build programme first, then work backwards. Everything else can be resubmitted. The exemption cannot.

To check which supporting documents your plot's constraints are likely to trigger, enter the postcode on PlanScope. 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.