Split and partial decisions on hybrid applications

A hybrid application is a single application seeking detailed permission for one part of a scheme and outline permission for the rest, and that single-application structure is what creates the problem on appeal. Section 79(1) of the Town and Country Planning Act 1990 lets an inspector deal with the application as if it had been made to them in the first instance, and reverse or vary any part of the decision whether the appeal relates to that part or not. A hybrid application appeal therefore reopens the detailed element you thought was settled, which is why the drafting of the application matters more than the drafting of the appeal.

What a hybrid application actually contains

The usual shape is a first phase in full detail, often the infrastructure, the spine road and a first parcel of buildings, with later phases in outline against parameter plans. One red line, one fee calculation, one description of development.

The components that make it work are a phasing plan, parameter plans fixing maximum and minimum heights, building zones, access points and areas of open space, and a design code or design guidelines for the outline phases. Reserved matters are then listed: layout, scale, appearance, landscaping and access, or whichever of those are not fixed.

Mixed applications of this kind are common on larger regeneration sites, where a developer needs certainty on a first phase to start work and flexibility on the rest. The attraction is obvious. The hazard is that everything sits inside one consent.

Article 5 and article 6 of the Development Management Procedure Order 2015 govern outline applications and reserved matters, and section 92 of the 1990 Act sets the time limits, including the period within which reserved matters applications must be made. Those periods run from the grant of the hybrid permission as a whole, which is the first practical consequence of combining the two.

How authorities issue a decision on one

A local planning authority determines the application that was made. It can grant, grant with conditions, or refuse, and section 70 does not contain a general power to grant part of an application and refuse the rest.

In practice three approaches are used.

• A single grant covering both elements, with conditions and a phasing requirement tying the outline phases to the detailed one.
• A single refusal covering the whole application, where the objection relates to the outline phases.
• An agreed amendment before determination, where the applicant withdraws or reduces part of the scheme so that what remains can be granted.

The third is the one to pursue when a committee is heading for refusal on a later phase. It requires agreement, and it requires the officer to be satisfied that what remains is still a coherent development that was properly consulted on. Where the amendment is substantial, re-consultation follows and the timetable slips.

Committees do sometimes attempt a split decision in substance by resolving to grant subject to the outline phases being removed. Whether that works depends on what was advertised and what the description of development says. A committee resolution that departs from the officer recommendation carries its own risks, and the broader point about committee refusals against officer advice applies here too.

Appealing part of a decision

There is no mechanism for appealing part of a refusal. The appeal is against the decision on the application, and the application is the whole hybrid scheme.

That has a practical consequence worth stating plainly. If an authority refuses a hybrid application because of the outline element, the appellant cannot ask the inspector to look only at that element. The inspector takes the application as a whole.

Where the authority has granted permission subject to a condition the applicant objects to, the appeal route is different: an appeal against the condition, or a section 73 application to vary it. An appeal against a condition does not put the permission itself at risk in the same way, though the inspector's power to look at the condition against the whole permission is wide.

Severability and what an inspector may do

Section 79(1) is generous. The inspector may allow or dismiss the appeal, reverse or vary any part of the decision, and deal with the application as if it had been made to them at first instance. Appeal decisions are indicative of how inspectors approach a question rather than binding, and the practical use of them is covered in using appeal decisions in a planning application.

Two limits constrain that power.

The first is that the inspector cannot grant permission for a development materially different from the one applied for. Reducing the number of dwellings in an outline phase by a small margin through a parameter condition may be acceptable. Deleting a whole phase and recasting the access strategy is not, because the public was consulted on something else.

The second is procedural fairness. An inspector minded to grant something other than what was applied for must give the parties the chance to address it. Where an inspector raises the possibility of allowing the appeal in respect of the detailed phase only, expect a request for written submissions on whether that is severable and whether the conditions still work.

Severability in practice turns on whether the detailed element can stand alone. Ask three questions. Does it have independent access from the public highway? Does it have its own drainage, utilities and open space provision, or does it depend on infrastructure in a later phase? Would the planning balance for the detailed element be the same without the rest of the scheme? If any answer is no, the scheme is not severable and the inspector will treat it as one.

Conditions and obligations that straddle both elements

Site-wide requirements are the practical reason hybrid permissions are hard to unpick.

A biodiversity gain plan for the whole site, an overall drainage strategy, a travel plan covering the completed development, an affordable housing obligation calculated across all phases, and a section 106 with triggers tied to occupation numbers all assume the full scheme. Remove a phase and the arithmetic changes.

Draft with that in mind. Express obligations as rates rather than totals where possible, so that an affordable housing requirement is a percentage of the units actually built. Tie infrastructure triggers to occupation thresholds within each phase rather than to a cumulative total. And include a mechanism for recalculation if phases change, because a deed that cannot be recalculated has to be varied by deed of variation, which takes months.

Conditions should be written phase by phase wherever the subject matter allows. A single condition requiring a site-wide scheme before any development starts will delay the detailed phase for the sake of a phase that may be years away.

The risk of losing the consented element

The sharpest risk is this. Where an authority grants a hybrid permission and a third party challenges it, or where the applicant appeals a refusal of the whole, the detailed element goes back into play.

Mitigation is available and it has to be chosen early.

1. Submit two applications, one full and one outline, with a linking mechanism in the section 106 rather than in the description of development.
2. Where a single application is unavoidable, draft the description so the two elements are plainly distinct and separately described.
3. Build independence into the detailed phase: its own access, its own drainage outfall, its own open space.
4. Agree a phasing condition that lets the detailed phase proceed without reserved matters approval for later phases, and keep pre-start requirements phase-specific.
5. Keep the detailed phase's evidence base self-contained, so its transport and drainage assessments stand without the later phases.
6. Where a refusal is likely on a later phase, negotiate an amendment before the committee date rather than appealing afterwards.

Option one is the strongest and the least used, usually because two applications cost two fees and two validation cycles. Against the cost of redetermining a consented first phase at appeal, that is a modest premium.

Drafting the application to keep the parts apart

Start from the description of development. A description that reads as a single integrated development invites an all-or-nothing decision, and a description that identifies the detailed element with its own red line and schedule of accommodation makes severance arguable.

Then make the documents match. Separate design and access statements for the detailed and outline elements, separate schedules of drawings, and an explicit statement of which documents support which element. Where the transport assessment covers the whole site, include a sensitivity test for the detailed phase alone.

A planning statement that sets out the structure of the application, explains what is detailed and what is outline, and states expressly that the elements are intended to be capable of separate determination gives both the officer and any later inspector something to work with. It is a paragraph that costs nothing and occasionally saves a phase.

See which reports a phased scheme needs by browsing the report categories and starting a draft.

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.