Guides
Guides for London homeowners
Practical, plainly-written explanations of the decisions behind a London home project — planning, drawings, fees, conservation and approvals.
Guides
Costs & fees
Fees
Architect Fees in London: How They Work
Architect fees vary with scope, stage and complexity. This guide explains common fee structures, what is included at each stage, and how to compare quotes fairly.
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What Affects the Cost of a House Extension in London
Extension costs vary widely with the property and the brief. This guide explains the factors that drive the price, so you can budget realistically — without relying on a single headline figure.
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What Affects the Cost of a Loft Conversion in London
Loft costs depend heavily on the type of conversion and the work it triggers elsewhere in the house. This guide sets out the main cost drivers, without quoting a headline figure.
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What Affects the Cost of a Basement in London
Basements are the most cost-intensive home projects. This guide explains what drives the price, from excavation and waterproofing to party walls and borough policy — with no headline figure.
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Planning Application Fees and Costs in London (2026)
A planning application has two main fees: the statutory fee paid to the council and the professional fee for drawings and submission. This guide separates both from third-party and construction costs.
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What Affects the Cost of a Kitchen Extension in London
A kitchen extension bundles several trades — structure, glazing, drainage and the kitchen itself — into one project, so a single rate per square metre rarely holds. This guide sets out the real cost drivers, from a side-return infill to the rear opening and the fit-out, and is explicit about the one number nobody can promise up front: the build cost.
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What Affects the Cost of a Side-Return Extension in London
A side-return infill looks small but touches a boundary, a roof, a drain and often a neighbour, and each of those is a cost driver. This guide sets out what actually moves the price — without quoting a build figure nobody can promise up front.
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What Affects the Cost of a House Refurbishment in London
Refurbishing an existing London home can cost as much as building new space, because so much of the value is hidden inside the existing envelope. This guide sets out what drives the price — from a cosmetic refresh to a full strip-out — without quoting a headline figure.
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Will You Pay CIL on a London Extension?
The Community Infrastructure Levy (CIL) is a local charge on new floorspace. Most home extensions are outside it, but larger extensions, annexes and new dwellings can be caught — and the exemptions are lost if you do not claim them before work starts. This guide explains the rules and the common trap.
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Planning decisions
Planning
Planning Drawings vs Building Regulations Drawings
Planning drawings and building regulations drawings do different jobs. This guide explains what each shows, why builders need technical drawings, and when structural calculations are required.
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Do I Need Planning Permission for a House Extension in Hampstead?
Whether a Hampstead extension needs planning permission depends on the property. This guide explains permitted development, why Hampstead is often more sensitive, and what to check.
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Conservation Area Extensions and Consents in Hampstead
Conservation areas shape what you can do to a home’s exterior. This guide explains why design quality matters, what is assessed, and how to approach a sensitive proposal.
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Camden Planning Permission for a Home Extension
Camden covers Hampstead, Belsize Park, Primrose Hill and more. This guide explains how the borough approaches home-extension applications, basements and what to prepare — grounded in published Camden materials.
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RBKC Planning Permission for a Home Extension
The Royal Borough of Kensington and Chelsea is known for rigorous policy and basement controls. This guide explains its approach to home-extension applications.
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Permitted Development Explained for London Houses
Permitted development can let some works proceed without a planning application — but in London it is heavily restricted. This guide explains what it covers and where it stops.
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Planning Conditions Explained: After You Get Permission
A planning permission almost always comes with conditions. This guide explains what they are, why pre-commencement conditions matter, and how they are discharged.
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Lawful Development Certificate Fees, Evidence & the 10-Year Rule in London
A Lawful Development Certificate is the formal, legal confirmation that works are lawful — either because they are permitted development or because they have become immune from enforcement. This guide explains the two types, why a certificate is worth having even when you are confident, the enforcement time limits, the fee and the evidence required.
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Biodiversity Net Gain and Home Extensions in London
Biodiversity Net Gain has applied to development in England since 2024, but householder applications — the route most extensions, lofts and conservatories use — are exempt. This guide sets out when BNG can still apply to a home project, and what the exemptions actually require.
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Garden Rooms and Outbuildings: Do You Need Planning Permission?
A garden room or outbuilding can often be built under permitted development — but the limits are specific, and in London a conservation area, an Article 4 direction or a listed building frequently changes the answer. This guide sets out the rules and the common traps.
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Change of Use for Homeowners: Working From Home, HMOs and Short Lets
Using your home differently — working from it, letting rooms, or short-letting it — can cross into a change of use that needs planning permission. This guide sets out where the lines fall for London homeowners.
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Paving a Front Garden and Dropped Kerbs: The Planning Rules
Paving a front garden for parking can need planning permission — but a permeable surface usually avoids it, whatever the size. This guide explains the 5 square metre rule, the drainage reason behind it, and the separate consent a dropped kerb requires.
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Solar Panels and Heat Pumps: Do You Need Planning Permission?
Solar panels and air source heat pumps are usually permitted development — and the heat pump rules were relaxed in 2025 — but conservation areas and listed buildings change the picture. This guide sets out the limits.
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Do You Need Planning Permission in London? The Complete Guide
Whether your London project needs planning permission depends on what you are doing and where. This guide sets out the principles, then points you to the detail for extensions, lofts, conversions, heritage work, basements and more.
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What Happens After Planning Permission in London
Planning permission is a green light on principle, not a green light to dig. This guide walks through the real next steps London homeowners face after approval.
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What Planning Officers Assess on London House Extensions
A practical map of what local planning authorities weigh on householder extensions in prime London — so you design a case, not just a bigger kitchen.
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Basement Planning in Camden vs RBKC
Two of London’s strictest basement regimes side by side — so NW3 and W8 clients stop assuming the rules are the same.
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Loft Conversion Process in London: Planning to Build
The full sequence from roof survey to tender — so loft companies and homeowners stop treating planning drawings as build information.
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Side Return Extension Process in London
The real sequence for Victorian closet-wing infills — geometry, neighbours, drains and consents — not just a glass roof mood board.
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Planning Drawings Validation Checklist for London Homes
A practical validation checklist so applications start the determination clock on the first submission — grounded in published borough requirements such as Southwark’s householder checklist.
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Dulwich Estate Scheme of Management Consent
Many Dulwich freeholds need written Estate approval for external works — separate from and additional to local authority planning. Here is the practical dual-track process.
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Planning Permission vs Licence to Alter in London
Planning permission is public law via the local authority. A Licence to Alter is private consent under the lease. Many London flat and converted-house projects need both — plus building regulations.
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Camden vs Westminster Householder Planning
Addresses on the Camden–Westminster edge (St John’s Wood, South Hampstead, Marylebone, Regent’s Park fringes) need the correct LPA before any red-line drawing is issued. The two boroughs do not share one householder culture.
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Dual Consent: Trust, Estate and Council in London
Some London neighbourhoods require private-law Trust or Estate approval as well as local authority planning. Treating them as one process is how projects stall after a grant.
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Basement Planning Evidence Across London Boroughs
Basements are almost always full planning territory in prime London. Evidence packages differ by LPA: Article 4s, BIAs, garden extent, estate dual consent and dual-borough authority checks.
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Extensions, lofts & basements
Extensions
Side Return Extensions in London: What to Know
The side return is one of the most effective extensions for a London terrace. This guide explains how it works, what it involves, and the practical issues to plan for.
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London Basements: Process, Cost Drivers and Risks
Basements add space without changing the street scene, but they are the most demanding home projects. This guide sets out the process, the cost drivers and the risks.
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Do You Need Planning Permission for a Loft Conversion in London?
Many loft conversions are permitted development — but not in a conservation area, where the rights are removed, and not for flats. This guide sets out the volume and design limits, and why so many prime-London lofts need a planning application.
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Rear Extensions: Permitted Development and the Prior Approval Route
A single-storey rear extension can often be permitted development, and a deeper one may be possible through the prior approval neighbour-consultation scheme. This guide sets out both, and the conservation-area limits that matter in prime London.
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Basement Impact Assessment: What London Boroughs Require
A Basement Impact Assessment is site-specific technical evidence for a basement planning application. It tests drainage, flooding, groundwater and structural stability; the trigger, scope and review process depend on the borough and proposal.
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Leasehold, flats & party walls
Leasehold
Licence to Alter Drawings for London Flats
Most London flat alterations need freeholder consent through a Licence to Alter. This guide explains the process, the drawings required and how consultants coordinate.
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The Party Wall Act Explained for London Homeowners
Most London extensions and basements engage the Party Wall etc. Act 1996. This guide explains when it applies, what the process involves, and how to plan for it.
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Converting a House into Flats in London: The Planning Position
Subdividing a house into flats — or combining flats back into a house — always requires full planning permission in England. This guide explains why, what London boroughs assess, and the building regulations and consents that come with it.
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Licence to Alter Process for London Flats
How freeholder consent actually works on London flats — what to prepare, what surveyors scrutinise, and how to sequence planning so works do not start half-approved.
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What Freeholder Surveyors Want on Licence to Alter Packs
Licence to Alter packs fail when they look like furniture layouts. Freeholder surveyors review risk: structure, drainage, fire, acoustics and construction method — often at building-control detail.
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Who Owns the Loft Space in London Flats?
In converted houses and mansion blocks the loft is frequently outside the flat lease. Freeholder consent can stop a loft before planning is even the main issue.
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Heritage & conservation
Heritage
Listed Building Consent: A Guide for London Homeowners
Listed buildings need consent for many alterations, inside and out. This guide explains what is protected, the risks of unauthorised work, and how to prepare a sensitive proposal.
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Trees, TPOs and Conservation Areas: What You Can and Cannot Do
A protected tree can shape — or stop — a London home project, and unauthorised work is a criminal offence. This guide explains Tree Preservation Orders, the notice you must give for trees in a conservation area, and what it means for extensions and basements.
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Replacing Windows and Doors in a London Conservation Area
Replacing windows and doors is often outside planning control — but in a conservation area with an Article 4 direction, and for flats and listed buildings, the position changes. This guide sets out when permission is needed.
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Demolition in a Conservation Area: When You Need Permission
Demolishing a building — or a substantial part of one — in a conservation area usually needs planning permission, and doing it without is a criminal offence. This guide explains "relevant demolition", the thresholds, and the position outside conservation areas.
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Process & construction
Compliance
Principal Designer Duties for Domestic Projects
The term “Principal Designer” covers two distinct roles. This guide explains the Building Regulations and CDM duties, the domestic-client context, and why written appointments matter.
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How Long Does a London Extension Take?
Extensions take longer than many expect once design, approvals and construction are added up. This guide sets out a realistic timeline and the common causes of delay.
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Choosing and Working With a Builder in London
The builder you choose, and the basis you appoint them on, shapes the whole construction stage. This guide explains how to tender fairly and work well with a contractor.
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Do I Need an Architect for an Extension?
You are not legally required to use an architect for most home extensions — but you do need proper drawings and, usually, approvals. This guide separates what the law demands from what a good outcome needs, and explains when paid design genuinely pays for itself.
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How to Choose an Architect in London
Choosing an architect is one of the earliest and most consequential decisions on a London home project. This guide explains how to verify credentials, compare fee proposals fairly, judge relevant experience, and recognise the red flags worth walking away from.
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Building Over a Public Sewer: Build-Over Agreements Explained
A public sewer running through a London garden can shape an extension or basement, and building over or near one needs a build-over agreement from the water company. This guide explains when it is required and why it is separate from planning permission.
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Refused Planning Permission? Householder Appeals Explained
A refusal is not the end of the road, but the options are time-limited. This guide explains the 12-week householder appeal deadline, how the Planning Inspectorate decides appeals, and when resubmitting a revised scheme is the better route.
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Building Regulations Approval: Full Plans or a Building Notice?
Almost every building project needs building regulations approval, separately from planning permission. This guide explains the two routes — full plans and a building notice — who you apply to, and the completion certificate you will need when you sell.
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How to Prepare for an Architect Consultation in London
A short, practical checklist for London homeowners so the first conversation produces a clear route and fee, not a vague sales call.
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If a guide does not answer your question, send us the details. We will advise on the likely drawings, approvals and consultant input your project may need.