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Haringey · N4 · N6 · N8

House Extensions in Haringey

Mix of Victorian terraces and 1930s semis — lofts and rear extensions dominate. Single and double-storey extensions delivered as a fixed-scope design and build package.

Typical Haringey cost
£50k–£220k
Timeline
1020 weeks

Postcodes covered

N4N6N8N10N15N17N22
Build estimator

Get a 60-second estimate

Indicative range
£45,000£120,000
814 weeks on site

Quick answer

Builderr delivers extensions across Haringey — N4, N6, N8, N10, N15, N17 and N22. Typical Haringey extension cost £58,000–£165,000 over 14–26 weeks. Crouch End and Muswell Hill Edwardian villas are ideal for double-storey side, side return and wraparound; Highgate heritage stock needs LBC for any external work. Tottenham and Wood Green PD-friendly for most rears.

Haringey

House Extensions specialists across Haringey.

We deliver house extensions projects across the full Haringey postcode set — N4, N6, N8, N10, N15, N17, N22. Mix of Victorian terraces and 1930s semis — lofts and rear extensions dominate.

Every Haringey project includes a free desk-based planning assessment before we quote, so you know upfront whether permitted development, prior approval, or full planning applies to your specific address. Our local project manager for Haringey has detailed knowledge of the planning department's preferences, the conservation area boundaries, and the common construction details for the prevailing housing stock here.

Quotes for Haringey house extensions are fixed-scope after a site survey, valid for 60 days, and never carry provisional sums or open-ended day rates. Every project includes our 10-year structural warranty and 12-month defects period.

Planning in Haringey

Local planning rules for house extensions in Haringey.

Haringey contains over 25 conservation areas including Highgate, Muswell Hill, Crouch End (Topsfield, Rookfield, Coleridge), Stroud Green, Tottenham Cemetery and South Tottenham. Article 4 directions cover wide residential zones in N6, N8 and N10. The council's Crouch End and Muswell Hill SPDs set strict design rules for extensions. Mansard lofts are preferred over rear dormers on heritage streets; many rear dormer applications are refused in N6 and N10.

Our planning team handles the full submission for Haringey addresses including drawings, Design and Access Statements where required, and pre-application consultation with the council. We tell you whether your house extension is permitted development, prior approval, or full planning before you sign anything.

Compare

Builderr vs other London builders.

The construction industry has a wide distribution of operators. Here's what changes between a directly-employed, fixed-scope outfit and the alternatives.

Builderr fixed price
£135,000
a house extension in Haringey · no provisional sums
Typical builder + variations
£162,000
+£27,000 vs Builderr (≈20% overrun)
Cowboy outfit + cost creep
£195,750
+£60,750 vs Builderr (≈45% overrun)
CriterionBuilderrTypical London builderCowboy outfit
Labour modelDirectly employed team (PAYE)Mixed subcontract gangsDay-rate cash labour
PricingFixed-scope itemised quoteEstimate + provisional sumsVerbal price + variations
Design & engineeringIn-house architect + SEOutsourced, separate billingBuilder draws on the back of an envelope
Planning + LDC handledYes — included in priceOften charged extraBuilder asks you to apply
Party wall surveyorsInstructed by usYour responsibilitySkipped (illegal)
Building controlPlans + site inspections booked by usBuilding Notice routeNot registered
Project managementDedicated PM, weekly photo updatesForeman doubles upOwner-manager juggles 5 jobs
Payment scheduleStage payments against signed-off milestonesWeekly invoicesCash up front
Insurance£10M PL + 10yr structural warranty£2–5M PL onlyNo documented cover
Snags at handover<3 typical20–30 typicalWalk-off mid-job common
Variation creep0% — fixed scope+15–25% over original quote+40%+ regularly
Bottom line

Save £27,000£60,750 on a house extension in Haringey.

Industry data (FMB, RICS, Which? Trusted Trader 2024) shows the average London construction project overruns by 18–22% on cost and 25–35% on time. Fixed-scope contracts with a single accountable team eliminate that variance. The savings above assume a typical project at £135,000.

FAQ

House Extensions in Haringey.

How much does a house extension cost in Haringey?

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Most house extensions projects in Haringey cost £50,000–£220,000 depending on size, spec and structural complexity. Inner London postcodes typically sit toward the upper end; outer borough projects trend mid-range. All Builderr Haringey quotes are fixed-price with no provisional sums.

Do I need planning permission for a house extension in Haringey?

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Planning rules vary across Haringey. We check permitted development eligibility, conservation area status and any Article 4 directions affecting your specific postcode before quoting. Many house extensions fall under permitted development, but conservation areas and listed buildings need full planning.

How long does a house extension take in Haringey?

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Typical timeline is 10–20 weeks on site, plus 4–8 weeks for design, structural engineering and approvals. If full planning is required (conservation areas, mansards, larger extensions), add 8–12 weeks for the planning decision before site start.

Do you have house extension references in Haringey?

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Yes — we maintain a live reference list for Haringey and can connect you with two or three completed clients within the borough. We've delivered projects across nearly every Haringey postcode since 2022, so most prospective clients can visit a completed project nearby.

What's included in a Builderr house extension quote in Haringey?

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Every Haringey quote covers structural design, party wall notices and surveyor coordination, planning or prior approval submission where required, building control, full build, snagging and a 10-year structural warranty. Kitchen units, sanitaryware and bespoke finishes are itemised separately so you can flex spec without losing fixed-price certainty on the build.

Get a Haringey house extension quote.

Senior consultant call within one business hour. Free desk-based planning assessment for N4, N6, N8 and surrounding postcodes. Fixed-scope price — no provisional sums.