Official constraint data (refreshed monthly) & live sold prices for all 33 London boroughs · Free to use
Every figure cited to source — how it works →
● A free property feasibility check · London flats, houses, extensions, conversions & refurbishments

Check the approvals, licences and risks
before you refurbish, alter or extend
your London property

Planning a flat refurbishment, house alteration, loft, basement or extension? Enter your property address to see early flags for Licence to Alter, planning permission, listed building consent, party wall matters, conservation-area limits, structural works and build-cost risks — before you call builders or commit to drawings.

Your property address

Checks may flagLicence to Alter · Planning Permission · Listed Building Consent · Party Wall · Structural Works · Conservation Area

Free — nothing to buySelect the exact propertyCited to official sourcesReferral to a regulated practice

The check is free. When you need the work done, we point you at one of two independent practices — Hampstead Architecture and Planning (ARB-registered architects) for design and consent, Hampstead Chartered Surveyors (RICS-regulated · Firm Reg. 923064) for condition, party wall and leasehold matters. This is an early-stage property check, not a guarantee of consent.

1107
Conservation areas mapped
33
London boroughs covered
Since 1995
Sold-price records analysed
Built on —
OS Open UPRNplanning.data.gov.ukHM Land RegistryEPC Open DataMHCLG Extract
BEFORE
WORKS START

What your property may need before works start

Plain English

Enter the exact property address and we flag the approvals, licences and risks that people often miss before calling builders — from Licence to Alter and listed building consent to party wall, planning, structural and cost issues.

Licence to Alter & leasehold consent

Flat or leasehold property? We flag where freeholder consent, a Licence to Alter or lease checks may be needed before works start.

Planning permission & permitted development

Whether the works may fall under permitted development, need a planning application, or need further checks before you rely on either route.

Listed building & conservation risk

Whether the property is listed, in a conservation area, or affected by restrictions where even internal or small external changes may need consent.

Party wall & neighbour matters

Whether shared walls, boundaries, excavations or structural works may trigger party wall notices before building work can start.

Structural works & building control

Flags where removing walls, forming openings, lofts, basements or structural changes may need structural calculations or building control approval.

Nearby decisions — where to read them

What neighbours got approved or refused is not in any national feed: every borough publishes it on its own planning register. We point you at the right register rather than pretend to have scraped it.

Build-cost & feasibility risks

An early cost range and warning signs such as awkward access, basements, drainage, listed details or unusual site constraints.

Suggested next steps

Which professional the result actually calls for — an architect for design and consent, a chartered surveyor for condition, party wall or leasehold process — before you spend more.

WHAT YOU
MAY NEED

From a free property check to the right next step

Signposting

Three steps, none of them paid. Check the address, read what actually applies to it, then take it to the practice that does that kind of work — architects for design and consent, chartered surveyors for condition, neighbours and leasehold process.

Step 01 · Free

Check the exact address

Resolve the property to its UPRN and check it against official constraint geometry: conservation area, Article 4, listed status, plus sold prices and indicative build-cost ranges for the works you have in mind.

Run a free check →
Step 02 · Free

Understand what applies

Each flag is labelled with its source, its confidence and what it changes: whether permitted development survives, whether the lease or the freeholder is in the way, whether the excavation is notifiable. Where a dataset is thin, we say so rather than guess.

How the check is built →
Step 03 · Who does the work

Talk to the right practice

Design, drawings and getting consent go to Hampstead Architecture and Planning (ARB-registered architects). Condition, defects, party wall notices and leasehold process go to Hampstead Chartered Surveyors (RICS-regulated · Firm Reg. 923064). Bigger jobs need both — an extension is designed and applied for by the architects while the surveyors serve the party wall notices.

Enquire with the architects →Enquire with the surveyors →

Professional services, when you need them

Most problems happen because owners call builders first. The check helps you work out which professional the job really needs — an architect for the design and the application, a chartered surveyor for condition, party wall notices and leasehold process — before works begin.

Licence to Alter

Renovating a leasehold flat? Your lease may require written freeholder consent first, and the freeholder wants a drawn, specified scheme to consent to. Hampstead Architecture prepare Licence to Alter packages.

Ask the architects →

Listed building consent

Own or buying a listedLegally protected building — consent needed for most changes, inside and out.Full definition → property? Internal and external changes may need listed building consent if they affect the building's character.

Read the guide →

Planning permission / lawful development

Extensions, roof works, external changes or a change of use: the route may be a full application, prior approval or a lawful development certificate. Hampstead Architecture handle applications, pre-application advice and appeals.

Ask the architects →

Party wall matters

Working near shared wallsA wall shared with your neighbour — legal notices required before working on or near it.Full definition →, boundaries or neighbouring structures? Notices may be needed before work starts.

Read the guide →

Internal alterations & building regs

Removing walls, forming openings, lofts or basements need drawings and a building-regulations route (with a structural engineer's calculations alongside). Hampstead Architecture produce the technical package.

Ask the architects →

Condition, defects & party wall

Buying, or worried about damp, movement or a neighbour's excavation? Hampstead Chartered Surveyors (RICS-regulated · Firm Reg. 923064) carry out building surveys, defect diagnosis, technical due diligence and party wall work.

Ask the surveyors →
01 /
06

A property check for the decisions before works start

Property check

One page for a confirmed London property address: early flags for approvals, licences, listed/conservation risk, party wall matters, structural works and indicative build-cost range — each clearly labelled and linked to its source where available, with the borough's own planning register named for the decisions no national feed carries.

Planning a flat refurbishment? The same property check can flag leasehold, Licence to Alter, listed/conservation, structural, party wall and building-control issues before you call builders. See which practice handles it →
Sample dossier — illustrative data
REF · SL-2026-04-19-NW3  ·  RETRIEVED 14:02 BST
CONSTRAINTS · HIGHPRECEDENT · HIGHUPLIFT · MEDIUM
PROPERTY · UPRN 10023198745

42 Pond Street

Hampstead · NW3 2PN · London Borough of Camden
TYPE · Terraced · MidEPC · D · 62TENURE · FreeholdCOUNCIL TAX · Band F
Likely route — proposed rear extension

Full planningA formal application your council must approve before you build.Full definition → required — not PDWork you can do WITHOUT a full planning application.Full definition →.

Property sits inside Hampstead Conservation Area (Sub-Area 3). Permitted development rights are modified. Recent approvals on this street suggest a 3m single-storey rear in matching stock brick is within policy.

Conservation AreaA protected area — stricter rules on changes to buildings.Full definition →Article 4 (partial)Extra restrictions — some normal building rights are removed here.Full definition →Not listedLegally protected building — consent needed for most changes, inside and out.Full definition →Party wall · both sidesA wall shared with your neighbour — legal notices required before working on or near it.Full definition →
Planning designations7 applied
Conservation AreaA protected area — stricter rules on changes to buildings.Full definition → Hampstead (Sub-Area 3)Applies
Article 4 DirectionExtra restrictions — some normal building rights are removed here.Full definition → HMO & shopfront onlyPartial
Listed BuildingLegally protected building — consent needed for most changes, inside and out.Full definition → Grade II within 50mNot listed
TPOTree Preservation Order — protected trees you can't cut or prune without permission.Full definition → zones within 30m3 present
Flood riskEnvironment Agency rating of how likely the land is to flood — Zone 1 is the lowest.Full definition → EA zoneZone 1 · low
CPZControlled Parking Zone — can affect planning for conversions.Full definition → Controlled Parking ZoneCA-G
Want to see the full free-dossier layout (routes, costs, constraints)? Open the sample dossier — illustrative data only →
Open sample dossier
03 /
06

Common London property works

What you may need first

Different works trigger different checks. A flat refurbishment, wall removal, loft, basement, garden room or extension may need different approvals, licences, structural input or neighbour notices before work starts.

WORK TYPE · 01

Flat refurbishment

Leasehold flat works may need freeholder consent, a Licence to Alter, building-control checks, structural input or listed-building consent before works start.

Cost range
Varies
Timeline
Varies
Route
LTA / checks
WORK TYPE · 02

Internal alterations

Removing walls, forming openings or changing layouts may need structural calculations, building control approval, lease/freeholder checks or listed-building consent before works start.

Cost range
Varies
Timeline
Varies
Route
Structural / BC / LTA
WORK TYPE · 03

Loft conversion

May be permitted development for some houses, but flats, conservation areas, Article 4 directions and listed buildings can change the route.

Cost range
£60–180k
Timeline
8–16 wks
Route
PD / Full
WORK TYPE · 04

Rear extension

May fall under permitted development for some houses, but conservation areas, flats, listed buildings and design constraints may require a full application.

Cost range
£45–110k
Timeline
10–16 wks
Route
PD / Full
WORK TYPE · 05

Basement dig

Often needs planning, structural design, drainage checks, party wall notices and careful feasibility review.

Cost range
£200–500k+
Timeline
6–14 mo
Route
Full + PW
WORK TYPE · 06

Garden room

May be permitted development if limits are met, but use, height, location, services, listed status and conservation constraints can change the route.

Cost range
£18–55k
Timeline
4–8 wks
Route
PD

All project guides — permitted-development limits, costs and approval odds →

04 /
06

What neighbours got approved — or refused

Register work

Recent decisions on streets like yours are the best available guide to what a council will actually accept. There is no reliable national feed of them: every London borough publishes decisions on its own public planning register, in its own format. Reading that register for a specific address is manual work — and it is work both practices do as a matter of course.

Who reads it, and why
  • Hampstead Architecture read the register when they build the planning case: which rear-extension depths, roof forms and materials this officer team has approved on comparable properties, and what drew a refusal.
  • Hampstead Chartered Surveyors read it on due-diligence and party wall jobs: whether a neighbour already has consent to excavate, what has been refused next door, and what that means for the property you are buying or living beside.
  • Either way it is judgement, not a lookup — which of those decisions is genuinely comparable to your property is the part that takes a professional.

Nearby decisions are context, never a prediction: a neighbour's approval does not bind your council, and where there are no comparable decisions nearby the honest answer is to say so. This free check does not scrape the registers — the borough pages tell you which register to search and link to it.

COUNCIL PUBLIC REGISTERS · NO AUTOMATED FEED, NO PLACEHOLDER DATA

05 /
06

Methodology & confidence

Why you can trust it

Planning Permission Checker is deterministic, not chatbot-first. A rules engine checks official datasets against the property's UPRNThe unique official ID number for your property.Full definition →. The language model only turns the results into a plain-English summary. It does not invent a constraint, price or approval.

Every claim carries a confidence tier. Where the data is thin or missing, we say so — and where the next step needs professional judgement, we hand you to a named regulated practice rather than a chatbot: Hampstead Architecture for design and consent, Hampstead Chartered Surveyors for condition, party wall and leasehold matters.

High
Structured data present, matched to UPRN

Your property sits inside (or outside) the authoritative dataset boundary. Cited to planning.data.gov.uk or Historic England. Good enough for early feasibility — verify before drawings, purchase, submission or works.

Medium
Partial coverage — directional, not definitive

The dataset is incomplete for this borough, or the boundary is approximate. Use for exploration; verify before submission. We flag this every time.

Low
Borough-specific manual review needed

Listed-building points, basement impact zones, TPO extents — these need a human checking the council register. We'll tell you what to look for.

STEP 01
Resolve to UPRN

OS Places API turns your typed address into a canonical UPRN and coordinate pair — the same identifier every dataset uses.

STEP 02
Run structured queries

UPRN and point queries against planning.data.gov.uk, EPC and Land Registry. Results are typed, sourced, and timestamped.

STEP 03
Score & classify

Each constraint is scored by coverage quality, and build costs come out as low / expected / high bands from calibrated per-square-metre tables — never a single number.

STEP 04
Write & cite

The LLM drafts the plain-English summary and the likely route. Every paragraph carries its source link. You can always click through.

WHY
TRUST IT

Why you can trust it

Sourced & reviewed

The check runs on official datasets, and the guidance around it is reviewed by a chartered surveyor. It is a clear first step before you spend money — not a substitute for formal professional advice, which is why the site's only next step is a named practice rather than a product.

Reviewed by a chartered surveyor

The guidance is reviewed for accuracy by Savas Bulduk MRICS, Director of Hampstead Chartered Surveyors & Building Consultancy (RICS-regulated · Firm Reg. 923064). Written by Planning Permission Checker Editorial, reviewed by a chartered surveyor before publication.

Nothing to sell you

The check is free and there is no report to buy, so nothing in the result is tilted towards an upsell. When work is genuinely needed we name the practice that does it — and we publish no fees for either, because their fees are theirs to quote.

London residential knowledge

London property works are shaped by borough rules, conservation areas, leasehold controls, neighbouring properties and local planning patterns — not generic national advice.

Transparent methodology

Every figure is labelled, every confidence level is shown, and where data runs out we say so. See the methodology →

What it is not. This is an early-stage feasibility and risk-screening tool. It is not a planning decision, not a valuation, and not a guarantee of consent. Depending on the property, formal advice may be needed from an architect, chartered surveyor, solicitor, structural engineer, party wall surveyor or other specialist.
06 /
06

Two practices, two different jobs

Free check · Regulated referral

The check itself is free and there is nothing to buy. What most people actually need next is a professional — and the mistake is calling the wrong one. Design, drawings and getting consent are an architect's work. Condition, defects, party wall notices and leasehold process are a chartered surveyor's. A rear extension typically needs both: the architects design it and apply for it, the surveyors serve the party wall notices on the neighbours.

NEXT STEP

Who to talk to next

Both practices work from the same building on Finchley Road, and both take enquiries directly — there is no form on this page and no middleman.

Hampstead Architecture and Planning
ARB-registered architects

The architect's door: designing the scheme and getting it consented — drawings, the planning application and the building-regulations package.

  • Residential design for extensions, lofts, basements and conversions
  • Planning applications, pre-application advice and appeals
  • Lawful development certificates
  • Building-regulations and technical design drawings
  • Conservation-area design and listed building consent applications
Hampstead Chartered Surveyors & Building Consultancy
RICS-regulated · Firm Reg. 923064

The chartered-surveyor door: professional judgement on condition, risk, party wall matters and leasehold process.

  • Building surveys, RICS home surveys and defect diagnosis
  • Party wall matters and awards
  • Technical due diligence before a purchase
  • Leasehold and major-works advisory (Section 20)
  • Dilapidations and building pathology

Both practices are independent and separately regulated — Hampstead Chartered Surveyors & Building Consultancy is an RICS-regulated firm (Firm Reg. 923064); Hampstead Architecture and Planning are ARB-registered architects. We publish no fees for their work: each quotes directly for the job in front of them. Your enquiry goes to the practice you choose — we never pass your details to builders or other third parties.

PLANNING PERMISSION CHECKER IS A FREE TOOL. IT IS NOT A SURVEYING OR ARCHITECTURAL PRACTICE, CARRIES NO REGULATORY REGISTRATION OF ITS OWN, AND EARNS NOTHING FROM YOUR CHECK. THE REGULATED WORK IS DONE BY THE TWO INDEPENDENT PRACTICES NAMED ABOVE.

FAQ

Common questions

Answered plainly
01

Is this formal planning advice?

No. Planning Permission Checker is a free, early-stage property intelligence and feasibility tool. It does not submit applications and does not make planning judgements. It shows you the clearest available picture of the constraints, the likely consent route and the honest unknowns, so that when you do instruct a professional you are briefing them from facts rather than guesses.
02

Does it cost anything?

No. The address and postcode checks are free, and there is nothing to buy on this site — we publish no reports for sale and no fees of our own. When a question needs professional judgement, we hand you to one of two named, independently regulated practices: Hampstead Architecture and Planning (ARB-registered architects) for design, drawings and the consent application, or Hampstead Chartered Surveyors & Building Consultancy (RICS-regulated, Firm Reg. 923064) for condition, party wall and leasehold matters. Each practice quotes you directly for the job in front of them; we publish no prices for their work.
03

Where does the data come from?

planning.data.gov.uk for structured constraints, OS Open UPRN and OS Places for the property spine, HM Land Registry Price Paid for comparables, and EPC Open Data for energy. Every field links to its source, and MHCLG Extract folds in as its rollout reaches the London boroughs. We do not hold a feed of nearby planning decisions: every application, officer report and decision notice is published on the council's own planning register, which is free to search and which we link you to for your borough. Reading that record against your specific scheme is professional judgement, not a data lookup.
04

How accurate are the build-cost ranges?

They are indicative planning-stage ranges, never a quote. Each project type is shown as a low / expected / high band, built from a cost-per-square-metre table and a typical floor area for that kind of work, labelled with its confidence and with the things that push a job towards the top of the range — awkward access, basements, drainage, listed fabric. The sold prices shown alongside are real HM Land Registry Price Paid transactions for the postcode; that dataset carries no floor areas, so we never turn it into a £/sqm figure or a value uplift. A real number comes from someone pricing a drawn scheme, and a formal valuation is a separate professional instruction this site does not provide.
05

Which London boroughs do you cover?

All 33. We have coverage across all 33 London boroughs using official constraint datasets where available — conservation areas and Article 4 directions from official sources, live house prices and hand-written borough commentary — and the address check works on any London postcode. Two limits we state plainly rather than paper over: we do not publish nearby application decisions, because those live on each council's own public register and we link you to it; and where a council's Article 4 geometry hasn't yet reached the national dataset we say "verify on the council register" rather than reporting a confident "none".
06

Is this just ChatGPT with a planning prompt?

No. A deterministic rules engine runs against structured government datasets. The language model only writes the explanation; it does not invent constraints or make planning judgements. Every claim carries a confidence tier and a source citation.
07

How is this different from a £10 AI planning report?

Three ways. First, the constraint answers aren't generated by a language model — they come from checking your property's own coordinates against the official constraint geometry, and anything we can't check is stated as not checked rather than guessed. Second, there is no "approval likelihood score": no algorithm can honestly score a London planning decision, so every figure is cited and confidence-labelled instead. Third, we don't sell you a report at the end of it. When the question needs judgement, it goes to a named professional — Hampstead Architecture and Planning (ARB-registered architects) for the scheme and the application, or Hampstead Chartered Surveyors & Building Consultancy (RICS-regulated, Firm Reg. 923064) for condition, party wall and leasehold matters — not to a bigger prompt.
08

Do you sell my data?

No. The professional-help buttons take you to one of two independent practices — Hampstead Architecture and Planning (ARB-registered architects) or Hampstead Chartered Surveyors & Building Consultancy (RICS-regulated, Firm Reg. 923064) — to enquire directly, so you choose which one gets your details and what you tell them. We don't pass your details to builders or other third parties, and we do not sell address lookups to brokers.
09

Should I call a builder first?

Usually, check the property risks first. A builder can price works, but they may not confirm Licence to Alter, listed building consent, planning permission, party wall, structural or building-control requirements. The free check helps you understand what to investigate before you spend money.

These questions on their own page →

Your property · free check · a named practice for the next step

Check the property before you commit.

Free — nothing to buySelect the exact propertyCited to official sourcesReferral to a regulated practice
Check an address