GLOSSARY

Planning language, decoded

38 terms · plain English · linked to the detail

Planning has a vocabulary that does real work: the difference between permitted development and prior approval, or between planning permission and building regulations, is the difference between a project that completes and one that stalls. These are the terms used across this site, defined once, with a link to the page that goes further.

Two habits are worth carrying into the rest of the site. A designation is an address-level fact, never a postcode-level one — boundaries are drawn street by street. And the consents are independent: planning permission, building regulations approval, a party wall award and a freeholder's licence to alter are four separate things, and holding one grants you none of the others.

DESIGNATIONS

Designations and constraints

The official labels attached to land and buildings. These are what decide whether your permitted-development rights still exist, and they are the layer this site checks against real published geometry.

Article 4 Direction

Also called: Article 4 · A4 direction

A direction made by the council that withdraws named permitted-development rights across a defined area, so work that would be automatic anywhere else needs a full application here. Article 4 directions are the single most common reason a project that looks like permitted development turns out not to be — they are often used to control front extensions, roof alterations, basements or conversions to shared housing. Crucially, the national dataset is known to omit some property-specific directions, so an absence of mapped geometry means 'unknown', never 'none': the council's own register is the only definitive source.

Article 4 directions explained → · Article 4 and HMO planning permission →

Conservation Area

Also called: CA · conservation zone

An area designated by the council for its special architectural or historic interest, where the character of the place as a whole is protected rather than any single building. Designation does not freeze the area, but it does tighten what you may do without applying: several permitted-development rights are reduced or removed outright, cladding and most side extensions need consent, and even work you can still do without permission is judged against the area's appraisal document. Boundaries are drawn street by street and often run mid-street, so a neighbour can be inside one while you are not.

Permitted development in conservation areas → · Check whether a postcode is in a conservation area →

CPZ

Also called: Controlled Parking Zone · permit zone

An area where on-street parking is restricted to permit holders during stated hours. It rarely affects an extension, but it is central to any application that creates a new dwelling or a new household: councils in controlled zones routinely grant permission subject to the new unit being 'car-free', meaning its occupiers are permanently ineligible for a parking permit. That condition runs with the property, so it is a material fact for a future sale, not just a planning detail.

Related: Planning condition, HMO

Designated land

Also called: article 2(3) land

The planning term for land carrying one of a specific set of protections — conservation areas, National Parks, the Broads, Areas of Outstanding Natural Beauty and World Heritage Sites. It matters because the permitted-development rules refer to it directly: on designated land, side extensions and rear extensions of more than one storey lose their permitted-development status, cladding rights go, and the larger single-storey rear extension prior-approval route is not available at all. In London the designation that brings a property into this category is almost always a conservation area.

Flood risk zone

Also called: Flood Zone 1 · Flood Zone 2 · Flood Zone 3

The Environment Agency's classification of land by its probability of flooding from rivers and the sea, running from Zone 1 (lowest risk) to Zone 3 (highest). It matters for planning because development in the higher zones can require a flood risk assessment and has to pass a sequential test, and it matters for basements in particular, where groundwater and surface-water risk are assessed as well. A flood zone is a site-level constraint, not a refusal — but it changes what evidence an application has to carry.

Related: Basement Impact Assessment

Listed Building

Also called: listing · Grade I · Grade II · Grade II*

A building placed on the national list for its special architectural or historic interest. Listing covers the whole building — interior as well as exterior — and normally extends to structures within its curtilage that pre-date the relevant cut-off, which is why garden walls and outbuildings are so often caught. Almost any alteration affecting its character needs listed building consent in addition to any planning permission, and carrying out unauthorised work to a listed building is a criminal offence, not merely a planning breach.

Listed building consent — what it covers →

Related: LBC, Curtilage, Conservation Area

TPO

Also called: Tree Preservation Order · protected tree

A Tree Preservation Order makes it an offence to cut down, top, lop, uproot or wilfully damage a protected tree without the council's written consent. Orders can cover a single tree, a group or a whole woodland, and separately, every tree of reasonable size in a conservation area is protected by default — you must give the council six weeks' notice before doing work to it. For a domestic project the practical impact is on foundations and on rear-extension footprints, since root protection areas can rule out building where you wanted to.

Related: Conservation Area, Curtilage

ROUTES

Routes to permission

There is no single thing called 'getting planning permission'. There are several distinct routes with different evidence, costs and timescales, and picking the wrong one is the most expensive ordinary mistake in a domestic project.

Change of use

Also called: material change of use · use class

Planning controls how a building is used, not only how it is built, and a material change of use is development requiring permission even if you lay no bricks. Uses are grouped into classes, and some movements between them are permitted development while others are not. The domestic cases that matter most are splitting a house into flats, and letting a house to enough unrelated sharers that it becomes a house in multiple occupation — both of which many London boroughs have brought under control by Article 4 direction.

Related: HMO, Article 4 Direction, CPZ

Full planning

Also called: householder application · planning application · full application

The standard route: a full application, assessed against the development plan and material considerations, and determined by the council's planning department or, for contested schemes, its planning committee. For a home extension this is normally a householder application, which carries a fixed national fee and an eight-week statutory target. It is required whenever a designation has removed your permitted-development rights, whenever the scheme exceeds the permitted-development limits, and always for a flat.

GPDO

Also called: General Permitted Development Order

The General Permitted Development Order — the statutory instrument that grants permitted-development rights and defines their limits class by class. When a guide quotes a rear-extension depth, an eaves height or a loft volume allowance, the GPDO is where that number comes from. It is national law, so councils cannot vary it locally; what they can do is remove rights within an area by making an Article 4 direction, or on a single site by attaching a condition to a permission.

LBC

Also called: Listed Building Consent

Listed building consent is the separate permission needed to alter, extend or demolish any part of a listed building in a way that affects its special interest. It is assessed on heritage impact rather than amenity, it carries no application fee, and it is required in addition to planning permission where both apply — obtaining one does not imply the other. Unauthorised work to a listed building is a criminal offence and there is no time limit that makes it lawful.

Listed building consent — what it covers →

LDC

Also called: Lawful Development Certificate · certificate of lawfulness · CLD · CLOPUD

A Lawful Development Certificate is the council's binding confirmation that a proposal is permitted development, or that existing work has become lawful through the passage of time. It is not permission — it is proof, and it is the document that stops a permitted-development claim from being re-litigated years later by a buyer's solicitor. Because the fee is a fraction of a full application and the certificate travels with the property, it is usually the cheapest insurance in a domestic project.

Lawful Development Certificates — cost and evidence →

Permitted development

Also called: PD · permitted development rights · PDR

A national grant of planning permission, given in advance by the Government, for defined categories of work within stated limits — so no application is needed as long as you stay inside them. The rights are precise and unforgiving: exceed a depth, a height, an eaves line or a volume by a small margin and the whole scheme becomes unauthorised development, not a partially permitted one. Permitted-development rights can also be removed — by a conservation-area or Article 4 designation, by a condition on an earlier permission, or because the property is a flat rather than a house — and flats never had householder permitted-development rights in the first place.

Permitted development in conservation areas → · Permitted development and leasehold flats →

Prior approval

Also called: prior notification · larger home extension scheme

A middle route between permitted development and a full application: the principle of the work is already granted, and the council only assesses specified matters before it can go ahead. For homeowners the common case is the larger single-storey rear extension, where the council notifies the adjoining neighbours and considers their objections about impact before issuing its decision. It is not available on designated land, it has its own statutory clock, and missing the notification step invalidates the whole route.

Prior approval for a larger home extension →

THE

The application process

What happens once an application goes in — who decides it, against what, how long it takes, and what your options are if the answer is no.

CIL

Also called: Community Infrastructure Levy · self-build exemption

A charge levied by the council on new floorspace, calculated per square metre and payable on commencement. Householder extensions are frequently relieved of it, but the relief is not automatic — the exemption has to be claimed and acknowledged before work starts, and starting first forfeits it entirely. That sequencing trap is the reason CIL turns into an unexpected five-figure bill on otherwise ordinary domestic projects.

CIL exemptions and how to claim them →

Determination period

Also called: 8 weeks · statutory target · target date

The period the council has to determine a valid application before you gain a right of appeal against non-determination. For a householder application the statutory target is eight weeks from validation, though in practice London boroughs commonly ask for an extension of time. The clock starts on validation, not on submission, which is why an incomplete drawing pack can quietly cost weeks before assessment even begins.

Enforcement

Also called: enforcement notice · breach of planning control

Where development has taken place without the permission it needed, the council can investigate and, if it considers it expedient, issue an enforcement notice requiring the breach to be remedied — which can mean undoing the work. Enforcement is discretionary rather than automatic, and unauthorised work can become immune after a statutory period, but immunity is a defence to be evidenced, not a certificate, which is why a Lawful Development Certificate is the clean way to settle it. Unauthorised work to a listed building never becomes lawful with time.

Retrospective permission and enforcement →

Free resubmission

Also called: free go · repeat application

After a refusal you are entitled to submit one further application for substantially the same development on the same site without paying the fee again, within twelve months of the decision. It is the mechanism most homeowners should reach for first: the refusal notice tells you precisely what the objection was, and an amended scheme that answers it is normally faster and far more likely to succeed than an appeal on the original design.

Material consideration

Also called: planning grounds · material planning consideration

A factor that is legitimately relevant to a planning decision — overlooking and loss of privacy, loss of light, design and impact on the character of an area, highway safety, heritage impact. The mirror of the definition matters just as much: things that are not material considerations cannot lawfully decide an application, and that includes loss of a private view, effect on property values, and the identity or conduct of the applicant. Reading a refusal properly means separating the material reasons from the rest.

Refused planning permission — reading the decision →

Neighbour consultation

Also called: consultation period · site notice · objections

The council notifies adjoining occupiers of an application — by letter, a site notice, or both — and allows a set period for comments. Comments are not votes: the council weighs objections that raise material considerations and disregards those that do not, and a scheme with many objections can be approved while one with none is refused. The larger home extension prior-approval route has its own version of this step, and skipping it invalidates that route entirely.

Planning appeal

Also called: Planning Inspectorate · PINS · householder appeal

An appeal against a refusal is decided by the Planning Inspectorate, an independent national body, not by the council. Only the applicant may appeal — neighbours cannot appeal an approval — and most householder appeals are decided on written representations. For most homeowners the better first move is not an appeal at all but a revised scheme using the free resubmission, since a refusal notice states its reasons and those reasons are effectively a specification for what would be acceptable.

Refused planning permission and appeals →

Planning condition

Also called: pre-commencement condition · conditions of approval

A requirement attached to a grant of permission, which the permission depends on. Some must be satisfied before you may start (pre-commencement conditions — materials, construction management, drainage details), others govern how you build or how the property may be used afterwards. Conditions are frequently used to remove permitted-development rights from a site, so a property that once had them may not any more, and building in breach of a condition is a breach of planning control even though permission exists.

Retrospective application

Also called: retrospective planning permission

An application made after the work is done. It is assessed on exactly the same planning merits as any other — being built already is not a material consideration in its favour — and it carries the ordinary fee. It is the normal route out of an unauthorised scheme that would in fact have been acceptable; where the work was genuinely permitted development all along, a Lawful Development Certificate is the better instrument because it confirms lawfulness rather than asking for a fresh grant.

Retrospective permission and enforcement →

Related: Enforcement, LDC

Validation

Also called: validation checklist · invalid application

Before assessing anything, the council checks the application against its published validation checklist — correct forms, correct fee, scaled existing and proposed drawings, a location plan, and whatever supporting statements the local list requires. Only once it passes does the determination clock start. Invalid applications are one of the most common causes of delay in domestic projects, and they are almost entirely avoidable with a complete drawing pack.

LEGAL

Legal and neighbour obligations

Consents that sit alongside planning permission rather than inside it. Planning permission does not override any of these, and several of them are commonly discovered far too late.

Building regulations

Also called: building regs · building control · Part A · Part L

The national standards governing how a building is constructed — structure, fire safety, insulation, ventilation, drainage, access — enforced through building control rather than the planning department. They apply to most building work regardless of whether planning permission was needed, so permitted development is not exempt from them. Planning asks whether you may build the thing; building regulations ask whether it is built safely, and a project can satisfy one and fail the other.

Planning permission vs building regulations →

Completion certificate

Also called: building regs sign-off · final certificate

The certificate issued by building control when it is satisfied the completed work complies with the building regulations. It is the document a buyer's solicitor asks for, and its absence is one of the commonest reasons a sale stalls on a house with an otherwise perfectly good extension or loft conversion. Getting one retrospectively is possible but costs more and sometimes requires opening up finished work.

Building control and completion certificates →

Conveyancing risk

Also called: missing consents · indemnity policy

The paperwork gap a buyer's solicitor finds: an extension with no permission or certificate, a loft conversion with no building control sign-off, alterations to a flat with no licence to alter. It is the mechanism by which an old, invisible shortcut becomes a live problem — typically a price reduction, an indemnity policy, or a delayed completion while consents are regularised. The cheap defence is to hold the evidence at the time: a Lawful Development Certificate, a completion certificate, and the licence.

Planning checks before buying a house in London →

HMO

Also called: house in multiple occupation · C4 use

A house in multiple occupation: a property let to several unrelated people who share facilities. Smaller HMOs can be permitted development in principle, but a great many London boroughs have removed that right by Article 4 direction, so a full application is required. Licensing under the Housing Act runs alongside and is a separate obligation — holding one does not satisfy the other, and enforcement of the planning breach is not prevented by holding a licence.

HMO planning permission and Article 4 →

Leasehold

Also called: lease · leaseholder

Ownership of a property for a fixed term under a lease, with the building itself owned by a freeholder. For planning purposes the decisive consequence is that flats have no householder permitted-development rights, so alterations that would be automatic in a house need a full application. On top of that the lease imposes its own private controls, typically requiring a licence to alter, and the two consents are independent of each other.

Permitted development and leasehold flats →

Licence to alter

Also called: LTA · licence for alterations · freeholder consent

The freeholder's formal written consent to alterations in a leasehold flat, granted under the terms of the lease. It is a private property right, wholly separate from planning permission — a council approval does not authorise work your lease forbids, and carrying out unlicensed alterations is a breach of covenant that can surface as a defect on sale years later. Most leases require it for structural work, and many require it for anything touching floors, services or the layout of wet rooms.

Licence to alter — leasehold flats →

Party wall

Also called: party wall notice · party wall award · Party Wall etc. Act 1996

A wall or structure shared with, or standing astride the boundary of, an adjoining owner's property. Work to it — and excavation within defined distances of a neighbour's foundations — triggers duties under the Party Wall etc. Act 1996: you must serve notice, and if the neighbour dissents, surveyors are appointed and an award is made before work may begin. This is entirely separate from planning permission: having permission gives you no right to proceed, and starting without the notices exposes you to an injunction.

Party wall agreements — notices, awards and timing →

Party wall award

Also called: award · schedule of condition

Where an adjoining owner dissents from a party wall notice, appointed surveyors produce an award: a binding document recording the works permitted, how and when they may be carried out, and the condition of the neighbour's property beforehand. That schedule of condition is the protection that decides who pays if damage is later alleged. The award is made under statute, not agreed by negotiation, and it must be in place before the notifiable work starts.

Party wall agreements — notices, awards and timing →

Related: Party wall, Boundary

PROPERTY

Property and site terms

Terms that describe the property itself — its identity, its boundaries, and the site conditions a design has to answer to.

Basement Impact Assessment

Also called: BIA · basement impact assessment

A structured technical assessment of how a proposed basement would affect groundwater, surface-water drainage, ground stability and neighbouring structures, prepared by qualified engineers and required by a number of London boroughs before a basement application can be determined. Boroughs that have adopted basement policies also commonly limit the extent and depth of what will be permitted. It is the single largest cost and programme item that distinguishes a basement application from any other domestic scheme.

Basement extensions in London → · Basement planning by borough →

Boundary

Also called: general boundaries · title plan

The legal division between your land and your neighbour's. Registered title plans are drawn to general boundaries and do not fix the line to the centimetre, which is why a dispute is settled by the deeds, the physical features and their history rather than by measuring the plan. It matters for planning because a scheme built to the edge assumes a line that may not be where you think it is, and it matters for party wall duties, which are triggered by proximity to it.

Related: Party wall, Curtilage

Curtilage

Also called: within the curtilage

The land and structures forming part and parcel of a building — typically the garden, boundary walls and outbuildings that serve the house. It matters twice over: permitted-development rights for outbuildings are expressed as a proportion of the curtilage that may be covered, and for a listed building, structures within the curtilage that pre-date the relevant cut-off are themselves listed. It is not the same as the title boundary, and the difference occasionally decides an application.

Heritage statement

Also called: heritage impact assessment · design and access statement

A written assessment identifying the significance of a heritage asset — a listed building, or the character of a conservation area — and explaining how the proposal would affect it. It is a validation requirement for most applications touching heritage assets, and it is the document that decides borderline conservation-area cases, because it is where the design is justified in the terms the decision will actually be taken on. A weak heritage statement is a common, avoidable reason for refusal.

Outcode

Also called: postcode district · postal district

The first half of a UK postcode, identifying a postal district that typically spans thousands of properties and often crosses borough boundaries. It is useful for orientation and genuinely useless for a designation answer: conservation-area and Article 4 boundaries are drawn street by street, so no postcode district is uniformly inside or outside one. Any honest district-level statement is about what lies near the district's centre, not about your house.

UPRN

Also called: Unique Property Reference Number

A Unique Property Reference Number: the persistent identifier the Ordnance Survey and local authorities use for an individual addressable property. It is what makes an address-level check exact — a postcode covers many buildings, but a UPRN is one of them, with its own coordinates. This site resolves your address to a UPRN before testing its coordinates against official constraint geometry, which is why the address check is more precise than the postcode check.

Related: Outcode, Curtilage

CHECK

Which of these apply to your address?

Definitions only get you so far. The free check tests your property's coordinates against the official conservation-area and Article 4 geometry and names what it finds.

Check your address

Planning Permission Checker provides planning and cost intelligence for early feasibility only. It is not legal, planning, valuation, architectural, structural, or surveying advice. All estimates are indicative and must be verified by qualified professionals before purchase, design, planning submission, or construction.

Cost estimates are indicative only — not a quotation. Final price depends on survey, specification, structure, access, party wall matters, VAT, professional fees, and contractor availability.

Planning outcomes are not guaranteed. Local planning authorities make final decisions.