A home extension cost in Paddington is rarely the tidy per-square-metre figure a national guide will quote. The white-stucco squares around Hyde Park Square and Gloucester Square are among the grandest terraces in London, and the first question here is not the rate. It is whether new floorspace can be added to a listed terrace, an estate-held house or a leasehold flat at all.
That is not a quibble. Much of Paddington is a conservation area, a large share of its terraces are listed, and the finest squares are held on the freehold by the Church Commissioners' Hyde Park Estate. Gardens are shallow, most homes are flats with no permitted development rights, and Westminster's basement and heritage controls are among the strictest in the country.
So an honest guide to Paddington answers two questions. What can you build between Sussex Gardens and Little Venice, and what does it cost when you can. The national benchmarks describe a different world - an open plot, a driveway, a crane. The Federation of Master Builders puts a single-storey extension at £1,800 to £3,000 per square metre; in W2 that barely covers the drawings and the consents.
A home extension cost in Paddington starts around £68,000 in 2026 for a small rear infill or closet-wing extension. A full-width lower-ground rear extension runs £125,000 to £245,000, a mansard or additional-storey roof extension runs £175,000 to £345,000, and a single-storey basement or vault scheme runs £340,000 to £730,000 and beyond. Per square metre that is £4,000 to £6,300 above ground and £6,300 to £9,800 for basement construction before fit-out. Those are Buildaway's own W2 quoting ranges. National guidance sits at £1,800 to £3,000 per square metre. The gap is estate or freeholder consent, listing, hand-carried structure, restricted hours and party wall exposure - not markup. And if you own a flat rather than a house, the realistic answer is usually that you cannot extend outwards at all.
What Does a Home Extension in Paddington Cost in 2026?
A home extension cost in Paddington falls into four bands in 2026. A small rear infill or closet-wing extension runs £68,000 to £125,000. A full-width lower-ground rear extension runs £125,000 to £245,000. A mansard or additional-storey roof extension runs £175,000 to £345,000. A single-storey basement excavation or vault conversion runs £340,000 to £730,000 and beyond. Each band covers design, structure, envelope, services, finishes and VAT.
Paddington Home Extension Cost, by Project Type
Buildaway W2 quoting ranges, 2026 - bars scaled to the top of each range
Source: Buildaway 2026 quoting data for Paddington extension projects. Not drawn from any third-party cost index.
| Project type | What it includes | Paddington range | On site |
|---|---|---|---|
| Rear infill or closet-wing extension | Existing footprint plus 8–15 m² beside the closet wing. New foundations, a structural opening, a glazed roof and a drainage diversion. | £68,000 – £125,000 | 12 – 18 weeks |
| Full-width lower-ground rear extension | 15–30 m² across the garden elevation. A steel goalpost, a lowered slab where needed, garden glazing and a finished room. | £125,000 – £245,000 | 20 – 30 weeks |
| Mansard or additional-storey roof extension | 25–45 m² of new upper floor. Full scaffold and a temporary roof, a slate and lead mansard, an extended stair and the fire and escape works. | £175,000 – £345,000 | 24 – 36 weeks |
| Basement or vault scheme, single storey | 30–60 m² below the lowest floor. Sequenced underpinning, temporary works, tanking on twin pumps, a new lightwell and fit-out. | £340,000 – £730,000+ | 40 – 70 weeks |
Per square metre is the more useful comparison once you are weighing one option against another. The table below shows how the same project types price out per square metre of new floorspace in W2. As before, these are our own 2026 figures, not a published index.
| Work type | Paddington rate per m² | What drives the spread |
|---|---|---|
| Above-ground period extension | £4,000 – £6,300 | Stucco and heritage detailing, glazing, and how much structure is hand-carried |
| Mansard or roof extension | £4,600 – £6,900 | Scaffold duration, lead and slate detailing, fire and escape strategy |
| Basement construction, before fit-out | £6,300 – £9,800 | Depth, the canal-side water table, and neighbouring foundations |
| Internal remodelling with structural openings | £2,400 – £3,700 | The realistic route in a flat: new structure and services, no new floorspace |
In proportion, the numbers make sense. ONS puts the average City of Westminster property at £836,000 in May 2026, and Paddington's stucco squares trade well above that, while its Bayswater-fringe conversions and Basin flats sit nearer the average. A new bedroom is measured against what a comparable house costs on the same square, which is why owners here extend rather than move - the stamp duty on trading up dwarfs the build.
Why does a W2 extension cost more than the rest of London?
The reasons belong to this postcode rather than the trade. Consent often runs through an estate or freeholder as well as the council, listing governs every visible surface, the council stops the working day at six, and on the stucco terraces there is nowhere to stand a crane, so structure arrives on shoulders.
- A double consent chain. Where the Hyde Park Estate or another freeholder holds the freehold, planning permission is only half the job. The estate licenses the work separately, on its own timetable, and the two rarely align.
- Listing on every visible surface. Stucco reinstated and painted to match, lead rather than a modern flashing, natural slate rather than a substitute, and sash joinery rather than a system window. On a listed terrace these are conditions, not choices.
- Restricted hours. Westminster's Code of Construction Practice permits work 08:00 to 18:00 on weekdays and 08:00 to 13:00 on Saturday. Nothing on Sundays or bank holidays, so programmes stretch and preliminaries run longer.
- No crane, no compound. A steel goalpost is lifted in half a day on a suburban plot. On a Paddington terrace it is cut, carried and bolted together in place, usually through the house.
- Kerbside economics. A Westminster skip licence costs £87 for up to two skips over one month, and on the stucco streets it only works alongside a paid parking bay suspension.
- ULEZ, not the Congestion Charge. Paddington sits outside the Congestion Charge zone, whose boundary runs along Edgware Road, so that daily charge does not bite here. But the London-wide Ultra Low Emission Zone still charges £12.50 a day for any non-compliant vehicle across a long build.
- Party wall exposure on two sides. A terraced W2 house has neighbours to the left and right, and excavating next to their foundations triggers statutory notices and, usually, two surveyors.
- Specification. Owners extending in Paddington are not buying a utility room. They are buying a room that has to sit convincingly inside a stucco terrace. That is a different product from a suburban rear extension.
For the wider comparison, our guide to single-storey rear extension costs in London sets out what the same work costs once the central constraints fall away.
Where does the money end up?
On a typical Paddington extension, structure and enabling take about a third of the budget before anything looks like a room, envelope and roof about a fifth, and services and fit-out a third between them. Fees, consent and contingency take what is left - the reverse of a suburban extension, where structure is cheap and fit-out dominates.
Where the Budget Goes on a Paddington Extension
Buildaway W2 project data, 2026 - indicative split on an above-ground extension
Source: Buildaway 2026 project data for Paddington and surrounding W2 extensions. Bars are scaled against the largest band, not against 100%.
On a stucco terrace nobody has actually seen the foundations, the drains predate any record drawing, and past owners each altered the structure without paperwork - so we hold a 7% to 10% contingency rather than the 5% a modern house would take. It is the difference between an honest fixed price and a running tally of variations.
How does cost change across Paddington?
- The Hyde Park Estate squares - Hyde Park Square, Gloucester Square, Sussex Square. Grand stucco terraces, mostly listed and held by the estate, with the closest design scrutiny and the clearest run at a lower-ground or basement scheme. Expect the top of our ranges here.
- Sussex Gardens and the Bayswater fringe - Norfolk Square, Talbot Square. Stucco terraces, many in hotel or conversion use, with strong demand for internal remodelling and roof space.
- Little Venice and the canal streets. Stucco villas with deeper gardens, where a lower-ground or garden extension has more room, under canal-side conservation control.
Can You Actually Extend a Property in Paddington?
For a large share of Paddington homes, the answer is no, at least not outwards. Permitted development rights apply to a dwellinghouse. A flat is not a dwellinghouse, so a mansion flat has no route to extend. Houses have rights on paper, but listing and conservation area status remove most of them. What remains is a planning application, the estate or freeholder's consent, and a clear-eyed look at where space actually exists.
Why a mansion flat cannot be extended
Schedule 2, Part 1 of the General Permitted Development Order, which grants the familiar rights to extend, is written for dwellinghouses. Flats are excluded entirely, which decides the outcome for the mansion flats around Sussex Gardens and Lancaster Gate and the apartments at Paddington Basin. Any enlargement needs full planning permission and the freeholder's consent, and the agreement of the leaseholders affected. GOV.UK guidance on planning permission is the starting point, but your lease is what governs you.
Houses fare better, though not by much. In a conservation area - article 2(3) land - side extensions and rear extensions of more than one storey fall outside permitted development, and where the house is listed the fabric is protected inside and out.
What Paddington owners build
So a Paddington home extension is nearly always one of five things. A rear infill beside the closet wing. A lower-ground extension into a shallow garden. A mansard or extra storey where the roofline can carry it. A basement dug beneath the existing footprint. Or, for flats, an internal remodelling that wins space without adding a square metre.
| Property type | Where you find it | What is realistically possible | Dominant constraint |
|---|---|---|---|
| Stucco terrace house | Hyde Park Square, Gloucester Square, Sussex Square | Closet-wing infill, lower-ground extension, basement, occasional mansard | Listing and the Hyde Park Estate licence |
| Stucco villa | Little Venice and the canal streets | Rear or lower-ground extension, basement, occasional mansard | Canal-side conservation and listing |
| Victorian or Edwardian mansion flat | Sussex Gardens, Lancaster Gate, off Praed Street | Internal reconfiguration, lateral conversion, top-floor roof space | No permitted development rights; the lease and other leaseholders |
| Period conversion | Norfolk Square, Talbot Square, the Bayswater fringe | Internal remodelling; rear infill where the demise allows | Hotel and multi-occupancy use next door |
| Mews house | The lanes behind the squares | Roof extension or third storey, internal remodelling | No crane access; everything hand-carried |
| Modern apartment | Paddington Basin and the station redevelopments | Internal remodelling in almost every case | Managing agent, warranty and building safety conditions |
If you own a flat and extension is closed to you, the money is usually better spent on the space you already have. Our guide to kitchen renovation costs in Paddington covers that route. Where the property is a house with roof space, a loft conversion in Paddington is often the cheaper way to the same bedroom.
What Consents Does a Paddington Home Extension Need?
A Paddington home extension usually needs planning permission from Westminster, listed building consent where the house is listed, the estate or freeholder's licence to alter where the home is estate-held or leasehold, and building regulations approval. Party wall notices sit alongside them. The first task is to establish who holds your freehold and what your lease permits.
Who holds the freehold of your building?
Paddington is part estate land and part mixed freehold. The Church Commissioners' Hyde Park Estate holds the grand stucco squares around Hyde Park Square, Gloucester Square and Sussex Square; off the squares, freeholds sit with private landlords, management companies and individual owners. So the practical question is whether the estate or another freeholder holds your building, and whether you own it freehold or leasehold - because a leasehold flat answers to the freeholder, whose consent usually fixes when work can begin.
What triggers a licence to alter?
Structural change triggers it, so does altering the building's appearance or installing plant, and in a flat even a new hard floor finish can, because those finishes carry impact noise downwards. Approval times vary by estate and landlord, so the pack is submitted early - and the clock only starts on a complete application with drawings, a specification and a method statement. An incomplete pack simply sits, which is the most common reason a Paddington extension slips by a month or two.
Which statutory consents apply?
- Planning permission. Assume you need it. The householder fee in England is £548 from 1 April 2026. Flats use a full application. Your scheme is judged against Westminster's City Plan 2019–2040, adopted on 21 January 2026.
- Basements need permission, always. Westminster's city-wide Article 4 direction came into force on 31 July 2016, removing permitted development rights for basement work. Policy limits a residential basement to one storey below the lowest floor and to no more than half the garden, with a method statement, ground water and drainage evidence and a construction management plan - and the canal-side water table matters.
- Listed building consent. Common on the Hyde Park Estate squares and the Little Venice villas. Historic England is blunt: unauthorised work to a listed building is a criminal offence under section 9 of the Planning (Listed Buildings and Conservation Areas) Act 1990, carrying up to two years in prison or an unlimited fine.
- Conservation area control. Paddington's stucco squares sit in conservation areas including Bayswater and the Hyde Park Estate. Westminster publishes audits and maps for each. Read them before an architect draws anything.
- Party Wall etc. Act 1996. A party structure notice needs two months' notice, and an excavation notice one month. On a terrace you usually serve both neighbours, each able to appoint a surveyor at your cost.
- Building Regulations. Part A covers the structure, Part B fire and escape, Part C ground moisture, Parts F, K and L ventilation, safety and thermal elements, and Part P the new circuits. Since April 2024 the private route is a Registered Building Control Approver.
- Community Infrastructure Levy. A scheme comes into charge at 100 m² of new floorspace, or where it creates a dwelling. An extension to your own home can claim the residential exemption, but only if it is claimed and granted, and a commencement notice served, before work starts. Westminster sits in Mayoral CIL band 1 alongside its own charging schedule.
- Working hours. Westminster's Code of Construction Practice permits 08:00 to 18:00 on weekdays and 08:00 to 13:00 on Saturday, with nothing on Sundays or bank holidays. Noisy work outside those hours needs consent under section 61 of the Control of Pollution Act, applied for at least 28 days ahead.
How Long Does a Paddington Home Extension Take?
Allow ten to eighteen months from first call to handover for an above-ground home extension, and eighteen to thirty months where a basement is involved. On site the work is twelve to eighteen weeks for a rear infill, twenty to thirty weeks for a full-width lower-ground extension, twenty-four to thirty-six for a mansard and forty to seventy for a basement. Consent, not construction, is the pacing item.
What Are the Hidden Costs of a W2 Home Extension?
The costs that catch Paddington owners out are the consent layer, the access layer and the neighbour layer - never contained in a national per-square-metre rate. Below are the twelve that turn up most often on W2 projects, with the impact we typically see.
| Line item | Why it applies in Paddington | Typical impact |
|---|---|---|
| Estate or freeholder licence deposit | Held against damage on an estate-held or leasehold home, returned after completion | Into five figures, out of your cash flow for the whole build |
| Legal costs, both sides | Your solicitor plus the estate or freeholder's costs of granting the licence | £3,000 – £8,000 |
| Party wall surveyors | Two neighbours, each entitled to their own surveyor at your cost | £2,500 – £6,000 per adjoining owner |
| Heritage consultant and design team | Listed and conservation work needs a heritage statement and robust drawings | 8 – 12% of construction cost across the full design team |
| Community Infrastructure Levy | Triggered at 100 m² unless the exemption is claimed before work starts | Avoidable in most cases, painful when the claim is missed |
| Skip licence and bay suspension | Westminster skip licence, plus a paid bay suspension | Recurring monthly across the programme |
| ULEZ charge | Paddington is outside the Congestion Charge zone, but ULEZ applies to non-compliant vehicles | £12.50 per non-compliant vehicle per day |
| Hand-carry and protection | No crane or compound; communal areas protected and reinstated | Adds labour weeks rather than material cost |
| Temporary works and propping | Propping schemes, underpinning sequences and mansard temporary roofs | £8,000 – £40,000 depending on scheme |
| Asbestos survey and removal | Common in mid-century repairs, and found on opening up | £500 survey; removal priced on discovery |
| Service diversions | Shared drainage and historic supplies that predate any record drawing | £2,000 – £15,000 |
| VAT | Standard-rated at 20%; 5% where a home has been empty two years or more | 20% of everything above |
How Do You Choose a Paddington Extension Contractor?
Judge a Paddington home extension contractor on consent fluency before you judge them on price. The contractors who finish on programme here can tell you, on the first visit, whether the Hyde Park Estate or another freeholder holds your freehold and what your lease permits, which notices your neighbours will receive, and how the structure gets into a listed terrace. Seven questions worth asking before you compare a single number:
- Who holds the freehold - the Hyde Park Estate or another freeholder - and have you prepared a licence to alter pack before?
- Is this house listed, and what will the heritage statement have to argue?
- Which party wall notices will my neighbours receive, and who pays for their surveyor?
- How does the structural steel physically get into the house, and what does that add to the programme?
- What are your working hours here, and how does that change the programme against a job outside Westminster?
- Does the quote include protection, licences, bay suspensions and any ULEZ charges, or are those excluded?
- Will you price against a consented scheme, or against a drawing that has not been approved yet?
The last one counts. A price given before consent is a guess wearing a spreadsheet.
You can see how we work locally on our page for home extension specialists in Paddington, which sets out how we run a Paddington home extension from feasibility to handover. Our home extensions service explains the design and build stages in more detail.
Planning an extension in W2? Buildaway handles the feasibility, the estate or freeholder licence pack, the planning application and the build as one team, with one fixed quote - conservation areas and listed buildings included.
Request a free quote →Frequently Asked Questions
How much does a home extension cost in Paddington in 2026?
A small rear infill or closet-wing extension on a Paddington terrace costs £68,000 to £125,000. A full-width lower-ground rear extension costs £125,000 to £245,000. A mansard or additional-storey roof extension costs £175,000 to £345,000. A single-storey basement excavation or vault conversion costs £340,000 to £730,000 and beyond. Per square metre, Buildaway's 2026 W2 rates run £4,000 to £6,300 above ground, £4,600 to £6,900 for roof work, and £6,300 to £9,800 for basement construction before fit-out. These are our own quoting ranges for W2, and they include structure, envelope, services, finishes and VAT.
Can you extend a flat in Paddington?
Usually not outwards. Permitted development rights under Schedule 2, Part 1 of the General Permitted Development Order apply only to a dwellinghouse. A flat is not a dwellinghouse, so there is no permitted development route to extend a Paddington mansion flat or a Paddington Basin apartment. Any enlargement needs full planning permission and the freeholder's consent under a licence to alter, and usually the agreement of the leaseholders affected. What is realistically available is internal reconfiguration, lateral conversion into an adjoining flat, enclosing a lightwell where the lease permits, and reclaiming roof space in a top-floor flat.
Do I need planning permission for a home extension in Paddington?
Almost always. Paddington's stucco squares sit inside conservation areas - the Bayswater and Hyde Park Estate areas among them - and many terraces are listed. On conservation area land, side extensions and rear extensions of more than one storey fall outside permitted development. Westminster also confirmed a city-wide Article 4 direction on 31 July 2016 removing permitted development rights for basement development, so every basement, lightwell and excavation needs planning permission. The householder application fee in England is £548 from 1 April 2026. (Westminster City Council; Planning Portal)
Do I need a licence to alter from the Hyde Park Estate?
If your freeholder is the Church Commissioners' Hyde Park Estate, yes, and it is usually the consent that sets your start date. The estate holds the freehold to the grand stucco squares around Hyde Park Square, Gloucester Square and Sussex Square, and a licence to alter is required to make structural change, alter the appearance of the building or install plant. Budget for your own solicitor, the estate's legal and surveyor costs, and a refundable deposit held against damage. Not every W2 address is the estate's - freeholds off the squares are mixed - so the first task is to establish who holds yours. (The Church Commissioners for England)
How long does a home extension take in Paddington?
Allow ten to eighteen months from first call to handover for an above-ground extension, and eighteen to thirty months where a basement is involved. On site, a rear infill takes twelve to eighteen weeks and a full-width lower-ground extension twenty to thirty weeks. A mansard takes twenty-four to thirty-six weeks, and a basement forty to seventy. The build is rarely the pacing item; planning determination, the estate or freeholder licence, listed building consent and party wall awards on two neighbours consume most of the programme, along with Westminster's restricted hours of 08:00 to 18:00 on weekdays and 08:00 to 13:00 on Saturday. (Westminster City Council)
Do I have to pay the Community Infrastructure Levy on a Paddington extension?
Only where the scheme creates 100 square metres or more of new internal floorspace, or creates a new dwelling. Even then, a residential extension exemption can be claimed on an extension to your own home, but it must be claimed and granted, and a commencement notice served, before work starts. Miss that sequence and the exemption is lost, and the levy is payable in full. Westminster sits in Mayoral CIL band 1 alongside its own charging schedule, and the Mayoral levy has been index-linked to the BCIS tender price index since it took effect on 1 April 2019. (Westminster City Council; Mayor of London)
So What Should a Paddington Extension Cost You?
Paddington's costs are high, but they follow rules you can learn. And a cost you can predict is a cost you can plan for.
- A home extension cost in Paddington starts around £68,000 for a rear infill. A mansard reaches £175,000 to £345,000, and basement schemes pass £730,000. Per square metre that is £4,000 to £6,300 above ground, and £6,300 to £9,800 below. (Buildaway 2026 quoting data)
- National guidance of roughly £1,800 to £3,000 per square metre describes an unconstrained site, not the same work at a discount. (Federation of Master Builders)
- Ask whether you can extend before you ask what it costs. Flats have no permitted development rights, and listing plus conservation status removes most of what houses have. Westminster's Article 4 direction of 31 July 2016 means every basement needs planning permission. (GOV.UK; Westminster City Council)
- Where the Hyde Park Estate or another freeholder holds your building, the licence to alter is the consent that sets your start date. Budget for the licence, legal costs on both sides and a refundable deposit into five figures. (The Church Commissioners for England)
- Plan for ten to eighteen months end to end above ground, and eighteen to thirty months with a basement. Consent and party wall awards are the pacing items, not the build.
- The strongest signal of a competent contractor here is fluency on tenure, listing, party wall notices, access and hours on the first visit.
At Buildaway we price Paddington extensions against a consented scheme rather than a hopeful one, and we build them under one fixed quote. To talk through your building's tenure and consent position, get in touch or see the areas we cover across London.