Party wall awards and basement consents compared

Planning permission says whether you may build a basement. A party wall award says how you may excavate next to your neighbour's building and who pays if something goes wrong. Neither one substitutes for the other, and a party wall award basement planning sequence that runs them in the wrong order is the most common reason a householder basement project stalls after permission is granted.

Two regimes with different jobs

The planning system is public law. The council decides whether development is acceptable in the public interest, weighing the local plan, amenity, heritage, trees and drainage. The decision is published, anyone can comment, and the council can enforce against a breach.

The Party Wall etc. Act 1996 is private law, and it applies in England and Wales. It governs the relationship between two landowners when one wants to work on a shared structure or excavate close to the other's building. The council has no role. There is no public register, no consultation, and nobody enforces it except the parties themselves through the courts.

The practical result is that you can have planning permission and still be unable to lawfully start, and you can be fully compliant under the 1996 Act and still be building without permission.

What planning controls on a basement

A basement dug wholly within the footprint of a house, with no external change, has commonly been treated as permitted development under Part 1 of Schedule 2 to the General Permitted Development Order 2015. Add a light well in front of the principal elevation, an external stair or a visible vent and you are usually into a planning application.

What the council looks at is the effect on the street scene, on neighbouring amenity, on trees, on drainage and surface water, and on any heritage asset. Several authorities require a Basement Impact Assessment by local policy, dealing with groundwater, ground movement and the effect on adjoining structures. That report looks at your neighbour's building, but it is produced for the council, not for the neighbour, and it does not discharge anything under the 1996 Act.

Flats are outside Part 1 altogether, so a basement to a flat or maisonette needs a planning application whatever its extent.

What the party wall process controls

Three sections do most of the work on a basement project.

Section 2 covers works to a party structure itself, such as cutting into a party wall, underpinning it or raising it. Notice is two months.

Section 1 applies where you want to build a new wall on the line of junction between the two properties. Notice is one month.

Section 6 is the one that catches basements. It applies where you excavate within three metres of a neighbouring structure and to a depth lower than its foundations, and also where you excavate within six metres and the excavation cuts a line drawn downwards at 45 degrees from the bottom of the neighbour's foundations. Notice is one month, and the notice has to be accompanied by plans and sections showing the proposed excavation.

Almost every habitable basement next to a terraced or semi-detached property triggers section 6, and many trigger section 2 as well.

Sequencing the two

Run planning first, then party wall, then building control, with one overlap.

1. Settle the design and obtain planning permission or confirm permitted development, because the depth and footprint are what the party wall notices describe.
2. Commission the structural and temporary works design to the point where the excavation sequence is defined.
3. Serve notices under the relevant sections, with drawings. Allow the full notice period plus time for dissent.
4. Appoint surveyors and obtain the award if the adjoining owner dissents or does not respond within 14 days, which counts as deemed dissent.
5. Submit the full plans application to building control, which can run in parallel with step four.

Serving notices before the design is fixed wastes the notice period, because a material change to the excavation means serving again. Leaving them until the contractor is appointed costs the programme, since an award on a contested basement can take two to three months once surveyors are instructed.

The condition survey of the neighbouring property, done before any work, serves both regimes. The same reasoning applies as on larger schemes, where a Structural Survey of what is being retained is the starting point, and structural surveys for a scheme relying on retention covers the method. Photograph everything, including cracks that were already there.

Surveyors, awards and security for expenses

If the adjoining owner dissents, each side either agrees a single surveyor or appoints their own, with a third surveyor selected to resolve disagreement between them. The award records the works permitted, the method and sequence, working hours, access arrangements, the condition survey and who pays the surveyors' fees. Fees normally fall on the building owner, which is to say you.

Section 12 lets an adjoining owner require security for expenses before the works start, usually a sum held in an escrow account or by a solicitor, calculated against the cost of making good if you stop part way through. On a basement that figure can be substantial, and it is a cash flow item people fail to budget.

An award can be appealed to the county court within 14 days of service. That is rare and expensive, and it is usually a symptom of a neighbour relationship that was mishandled at the start.

Where a planning condition touches the neighbour

Conditions cannot require you to comply with the 1996 Act, because the Act applies regardless and a condition duplicating other legislation is not normally justified. What conditions do instead is control the things planning can control.

Where scaffolding, hoarding or a skip occupies the footway, that is a separate licence from the highway authority, and the process for a scaffold licence and highway occupation runs on its own timetable. The temporary propping design that the award will describe is a designer duty in its own right, covered in temporary works design and designer duties.

Misunderstandings that cause delay

Four come up repeatedly.

That the neighbour can stop the basement. They cannot. Dissent leads to an award setting conditions on how you work, not to a veto. Only the planning system can refuse the development.

That planning permission authorises the excavation. It authorises the development in land use terms. Entering onto or undermining a neighbour's land needs the 1996 Act procedure.

That a basement impact assessment satisfies the party wall surveyor. It informs the discussion and will usually be requested, but the award is based on the structural and temporary works design, not the planning report.

That an objection to the planning application is the neighbour's only chance to be heard. The party wall process gives them a surveyor, a condition survey and a right to compensation, which is often more useful to them than an objection letter. Saying so early tends to lower the temperature considerably.

This is general guidance, not legal advice. The Party Wall etc. Act 1996 is a private law regime and disputes under it are matters for the parties and the courts, so take advice from a party wall surveyor and your local planning authority before relying on anything here. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.