Mortgages & Property

Self-Build House Guide UK — Planning, Costs & Mortgages

A complete guide to building your own house in the UK — from finding land and getting planning permission to self-build mortgages, costs, and project management.

Mortgage information is general guidance only. Mortgages are regulated by the FCA. YOUR HOME MAY BE REPOSSESSED IF YOU DO NOT KEEP UP REPAYMENTS ON YOUR MORTGAGE. Consult an FCA-regulated mortgage adviser before making decisions.

Building your own home gives you complete control over design, layout, and specification. Here’s everything you need to know about self-building in the UK.

Self-Build Overview

FeatureDetail
Average build cost (excl. land)£1,500–£3,000/sqm depending on spec
Average UK self-builds per year~12,000–15,000
Typical build time12–24 months (after planning)
VAT reclaimYes — on new builds
CIL exemptionYes — self-builds exempt from Community Infrastructure Levy
Right to Build registerLocal councils must keep a register of people wanting to self-build

Typical Costs

Build Cost per Square Metre

SpecificationCost/sqm100 sqm house150 sqm house200 sqm house
Basic£1,500–£1,800£150,000–£180,000£225,000–£270,000£300,000–£360,000
Good£1,800–£2,200£180,000–£220,000£270,000–£330,000£360,000–£440,000
Excellent£2,200–£2,800£220,000–£280,000£330,000–£420,000£440,000–£560,000
Outstanding£2,800–£3,500+£280,000–£350,000+£420,000–£525,000+£560,000–£700,000+

Full Project Budget

Cost elementTypical rangeNotes
Land£50,000–£500,000+Huge variation by area
Build costs£150,000–£400,000Based on size and spec
Professional fees (architect, engineer, project manager)10–15% of build cost£15,000–£60,000
Planning permission£462 (current fee for a new dwelling)Plus any pre-application advice
Building regulations£500–£2,000Depends on council and project size
Warranty (structural)£1,500–£3,500NHBC, LABC, Premier Guarantee, etc.
Site preparation£5,000–£30,000Demolition, access, services
Utilities connections£5,000–£20,000Water, electric, gas, drainage
Landscaping£5,000–£30,000Driveway, garden, fencing
Contingency (10–15%)£15,000–£60,000Essential — unexpected costs always arise
Total£250,000–£1,000,000+Depends on land, location, size, specification

Finding Land

SourceDetail
Plotfinder.netLargest UK self-build plot database
Rightmove/ZooplaSearch for “land” or “building plot”
Local estate agentsSome specialise in land sales
Auction housesLand plots often sold at auction
Local council Right to Build registerRegister your interest — councils must provide plots
Direct approachIdentify potential plots and approach landowners directly
Local newspaper classifiedsOccasionally list plots

What to Check Before Buying Land

CheckWhy
Planning historyHas planning been granted or refused before?
Title deeds and covenantsAny restrictions on building?
AccessIs there legal access to the plot?
ServicesAre water, electricity, gas, drainage available or do they need connecting?
Ground conditionsGet a soil survey — bad ground can add £10,000+ to foundation costs
FloodingCheck the flood risk map
TreesTPOs (Tree Preservation Orders) can restrict what you build and where
ContaminationPrevious industrial use may mean costly remediation
NeighboursTalk to them — any boundary disputes?

Planning Permission

StageDetailCost
Pre-application adviceInformal discussion with planning officer£50–£600
Outline planningEstablishes the principle of building (not detailed design)£462
Full/detailed planningDetailed plans for assessment£462
Decision timeTypically 8–13 weeks
Planning conditionsYou’ll need to satisfy conditions before and during build

Self-Build Mortgages

FeatureArrears stageAdvance stage
When funds releasedAfter each stage is completeBefore each stage begins
Cash needed upfrontYes — you fund each stage then get reimbursedNo — funds released to start each stage
Interest rateLowerHigher (typically 0.5–1% more)
Best forThose with savings/cash reservesThose who need funds to start each stage
Number of stages4–64–6

Typical Release Stages

Stage% of build cost released
Land purchaseSeparate land mortgage or deposit
Foundations15–20%
Wall plate (walls built to roof level)15–20%
Wind and watertight (roof on)15–20%
First fix (plumbing, electrics, plastering)15–20%
Second fix (kitchens, bathrooms, finishing)10–15%
CompletionFinal release / retention

Self-Build Mortgage Lenders

LenderTypeNotes
BuildStoreBroker/portalLargest self-build specialist — access to multiple lenders
Ecology Building SocietyDirectSpecialises in sustainable and self-build
Bath Building SocietyDirectSelf-build and custom build mortgages
Furness Building SocietyDirectSelf-build products
Mainstream lenders (e.g. Halifax, Nationwide)LimitedSome offer self-build but criteria can be restrictive

Build Routes

RouteYou manageCostControlRisk
DIY buildEverything yourselfCheapestMaximumHighest (quality, time, safety)
Self-manage with subcontractorsYou hire individual tradesLowerHighMedium
Main contractorOne builder manages everythingMid–higherMediumLower
Project manager + subcontractorsPM manages trades for youHigher (PM fees 10–15%)MediumLower
Package/kit home supplierPre-designed home erected on your plotVariableLower (limited design changes)Lower
TurnkeyDeveloper does everything, you get a bespoke homeHighestLowerLowest

VAT Reclaim

DetailInformation
Who can claimDIY housebuilders building a new dwelling
What you can claimVAT on building materials and some contractor services
When to claimWithin 3 months of completion (HMRC may extend if asked)
FormVAT431NB (new build)
How muchTypically £5,000–£30,000+
What you needAll VAT invoices (must be in your name)
What you can’t claimProfessional fees (architect, engineer), tools and plant hire, furniture/soft furnishings

Insurance You Need

InsuranceWhenWhy
Site insuranceDuring constructionCovers theft, damage, public liability
Structural warrantyBefore completionRequired by most mortgage lenders — 10 years
Self-build insuranceThroughoutCombines site insurance, employer’s liability, public liability
Buildings insuranceAt completionStandard home insurance

Your home may be repossessed if you do not keep up repayments on your mortgage. PocketWise provides information and guidance — we do not offer financial advice. Seek independent mortgage advice before making decisions about borrowing.

Sources

  1. FCA — Mortgages
  2. MoneyHelper — Buying a home