Knowledge Base
Planning, regulations and construction, explained.
Topic 01
Start here: planning your project
The first questions every client has: what happens, in what order, what it costs and how long it takes.
20 articles
The journey
01From idea to completion: the stages of a home projectA home project usually moves through feasibility, design, approvals, technical preparation, construction and handover. Agree what must be decided and delivered at each stage before committing to the next.02Extend, convert the loft or move?Compare extending, converting the loft and moving against the same space requirements and whole-project budget. The best choice is the one that solves your actual problem without relying on an untested design, borrowing assumption or resale-value promise.03What can I build on my property? Feasibility explainedFeasibility is an early check of what your property can accommodate, which permissions may be needed and whether the proposal is practical to design and fund. It identifies options and risks; it is not planning permission or a guarantee that a scheme can be built.04Do I contact a builder first, or get drawings done?You can speak to builders early, but obtain a defined design and scope before treating a price as a reliable construction quotation. With design & build, design and construction can be commissioned together; the written appointment still needs to identify who is designing what.05Planning permission, building regulations and party wall: three separate processesPlanning permission, building regulations and party wall matters address different issues, so resolving one does not resolve the others. Party wall procedure is a civil notice and dispute-resolution process rather than a council approval.06Measured surveys: why accurate information matters before designA measured survey gives the design team a checked record of the building and site rather than relying on approximate dimensions. The scope should match the proposed work and the reliable information already available.07Architect, architectural designer or planning consultant: who do I need?Choose the skills and appointment scope your project needs, rather than relying on a job title alone. An architect or architectural designer may lead the building design, while a planning consultant can be appointed for planning advice and strategy; structural engineering is a distinct specialist role.
Costs
08How much does an extension, loft or basement cost in London?There is no dependable single price for a London extension, loft conversion or basement without defining the property, design and specification. Build a project-specific budget that separates construction, professional services, approvals, VAT and unresolved risks rather than treating an online price per square metre as a quotation.09Professional fees: drawings, structural engineer, building control, party wall, consultantsProfessional fees pay for defined services, not a standard bundle that is identical on every project. Compare written scopes for design, engineering, building control, party wall work and specialist reports, and identify which services and expenses sit outside each quotation.10Council fees: planning application fees, CIL, building control chargesAllow separately for the planning application fee, building control charges and any Community Infrastructure Levy liability. They pay for different things, and the amount depends on the application, council, proposal and available exemptions—not simply the size of the builder’s quotation.11VAT on building work: when it is 0%, 5% or 20%Most work to an existing home is charged at 20% VAT, while qualifying new-home construction can be zero-rated and certain conversions or empty-home renovations can qualify for 5%. The rate follows HMRC’s conditions for the particular supply, not a project’s marketing label or the fact that it has planning permission.12Hidden costs clients don't expect: surveys, Thames Water, utilities, licencesThe costs most easily missed are work and permissions outside the obvious building package: investigations, drainage, service alterations, highway licences and the arrangements needed while your home is a building site. Identify who is responsible for each item before comparing quotations.13Paying for the project: savings, remortgage or a loanSavings, a further advance, remortgaging and a personal loan can fund different amounts and repayment periods; none is automatically best for every project. Compare the full repayment cost and the risk to your home, and confirm when money will actually be available before committing to building payments.
Timelines
14How long does the whole project take, from first drawings to moving back in?The whole project takes longer than the period spent deciding a planning application: surveys, design, technical preparation, procurement, construction and handover all need time. Use a programme built around your particular approvals and decisions, not a universal number of weeks from first drawing to moving back in.15How long does planning take, and what delays a decision?Most householder planning applications have an eight-week statutory decision period once valid; major development generally has thirteen weeks and Environmental Impact Assessment applications sixteen weeks. These are not guaranteed approval dates, and preparation, validation issues, agreed extensions and post-decision requirements can add time.16When can the builders start?Builders can start the relevant work when the required planning position, pre-start conditions, building control arrangements and any necessary third-party permissions or notices are in place. Planning permission alone is not a complete start-on-site clearance, and the checks must relate to the actual work about to begin.
Before you begin
17Checking your property's planning history and constraintsCheck the council’s planning records and constraints map, then read the actual decisions, conditions and relevant designations for your address. Online maps are a starting point, not proof that every past alteration is lawful or that no further restriction exists.18Leasehold flats: freeholder consent and lease restrictionsFor a leasehold flat, read the lease before commissioning alterations and obtain the landlord’s written consent where it is required. Planning permission and building regulations approval do not override the lease, and parts such as the roof or structure may be outside the area you own.19Restrictive covenants on your titleA restrictive covenant is a private legal restriction on how land may be used or developed, and it can prevent work even where planning permission has been granted. Check the title and any referred deeds before committing to a design, because the covenant’s wording and who can enforce it matter.20Telling your mortgage lender and home insurerTell your home insurer about significant building work before it starts, and check your mortgage terms for notification or consent requirements. Obtain a written response that reflects the actual work and occupancy arrangements; neither the builder’s insurance nor planning permission is a substitute for checking your own position.