Rear Extension Drawings in Hornsey N8
Fixed-fee, MCIAT-chartered rear extension drawings for Hornsey (N8) homeowners — London Borough of Haringey validation and local constraints handled from the start.
Hornsey (N8) sits between its historic High Street and the Crouch End fringe in the London Borough of Haringey, a mostly Victorian and Edwardian district of terraces and semi-detached family houses. Rear and side-return kitchen extensions and rear-dormer loft conversions are the everyday projects, driven by growing families staying put rather than moving on.
Three conservation areas shape the work here: Hornsey High Street around the old centre, the Crouch End area bleeding in from the south-west, and the small Campsbourne cottage estate near the church, where the modest terraces are unusually sensitive to roof and frontage change. We check an N8 Hornsey address against each boundary before drawing, and design rear dormers and extensions to sit within Haringey's residential guidance and the established roofline.
Planning in Hornsey (N8): what to know before you apply
N8 Hornsey has no published householder Article 4 direction, so many houses keep permitted development rights for rear and loft work — but the Hornsey High Street, Crouch End and Campsbourne Cottage Estate conservation areas cover the historic centre and its edges, where frontages, shopfronts and cottage rooflines are controlled. Elsewhere the consistent Victorian and Edwardian rooflines mean rear dormer scale and position are assessed closely against the local pattern.
Typical Hornsey housing stock
Victorian and Edwardian terraces and semi-detached houses spreading between the old Hornsey High Street and the Crouch End fringe, with the modest Campsbourne cottage-estate housing near the church and larger villa-scale homes on the rising ground toward Alexandra Palace.
Streets we regularly draw for in Hornsey
Denmark Road · Wolseley Road · Raleigh Road · Lausanne Road
What N8 is actually built of
Measured from 237 classified residential buildings in N8, not from a description of the area.
Hornsey N8 housing mix
Residential building form across the N8 postcode district, from 237 classified buildings.
| Attached on more than one side | 73% |
|---|---|
| Attached on one side | 25% |
| Detached | 3% |
| Median building footprint | 75 m² |
| Addresses per buildingAbove about 2 means flats and maisonettes dominate | 2.46 |
| Buildings classified | 237 |
Source: Ordnance Survey National Geographic Database (derived statistics). Contains OS data © Crown copyright and database right 2026. Contains Royal Mail data © Royal Mail copyright and database right 2026. Extracted 2026-08-17.
Rear Extension Drawings for Hornsey (N8) homes: the package and the process
Depth is the number the application turns on, and it has to be measured from the original rear wall of the house rather than from whatever is there now. The drawings carry that dimension, the eaves and ridge heights, the position of any rooflight, and the boundary distances on both sides.
Where the scheme goes beyond the standard allowance and relies on the larger home extension route, the drawings serve a second purpose: they are what the council sends to the neighbours during the consultation. A clear, dimensioned proposed elevation answers the objection about overshadowing before it is made.
Depth is limited by the plot as much as by the rules. A long garden behind a terrace can take the full allowance, while a short one runs out before the rules do — and on a semi or detached house the same depth reads very differently from the boundary.
Do I need planning permission for a rear extension in London?
Many single-storey rear extensions qualify as permitted development, meaning no planning application is needed, provided depth, height and materials stay within set limits. That changes if your property sits in a conservation area or is subject to an Article 4 direction, both of which can remove permitted development rights across a street or borough — in that case a full householder planning application is required regardless of size.
Even where an extension qualifies, most homeowners obtain a Lawful Development Certificate to confirm that status in writing before building — useful for mortgage lenders, buyers and Building Control. We check your property against your borough's constraints before recommending a route.
How deep can a single-storey rear extension go?
Depth is the main constraint on a rear extension, and it depends on your house type and whether you use standard permitted development or the larger home extension scheme.
Permitted development
Standard permitted development allows a single-storey rear extension up to 3 metres deep for terraced and semi-detached houses, or 4 metres for detached houses, generally with eaves height limited to match or stay close to the existing house.
Larger home extension scheme
The prior-approval scheme extends this to 6 metres for terraced and semi-detached houses and 8 metres for detached houses. Your council writes to affected neighbours; if none object within the notification period, approval follows without a full planning application. If an objection is raised, the council assesses the impact on neighbouring light and outlook itself, rather than automatically refusing, so a well-considered design still has a good chance of approval.
Designing the kitchen-diner: rooflights, bi-folds and daylight
Most rear extensions exist to create one open-plan kitchen, dining and living space, so the drawing work focuses on getting light and flow right within the depth you are allowed.
- Structural opening sized for bi-fold or sliding doors across most of the rear elevation
- Rooflights or a roof lantern positioned to light the centre of the room, away from the shadow line of the main house
- Open-plan layout tested against the 45-degree rule, which protects daylight to your neighbours' windows and can limit how close a flank wall or roof comes to the boundary
- Floor build-up and threshold detail coordinated so the new floor meets the existing one without a step
| Route | When it applies | Typical fee |
|---|---|---|
| Permitted development (Lawful Development Certificate) | Depth within 3m (terraced/semi) or 4m (detached), height and materials within PD limits | PD/LDC pack ~£950–£1,450 |
| Larger home extension (prior approval) | Depth up to 6m (terraced/semi) or 8m (detached), with neighbour notification | from £1,100 |
| Full householder planning permission | Extension exceeds PD/larger-home limits, or the property is in a conservation area with an Article 4 direction | Full Planning pack ~£1,600–£2,400 |
| Planning + Building Regulations (structural) | Combined planning and construction-ready pack with structural calculations for the opening and roof | Planning + Building Regs pack ~£2,200–£3,850 |
Rear Extension Drawings in Hornsey N8 — FAQs
How much does a rear extension cost to design in London?+
Do I need an architect for a rear extension?+
How long does it take to get rear extension drawings?+
What is the 45-degree rule?+
Will I need a Party Wall Agreement for a rear extension?+
Do I need planning permission for a loft conversion in Haringey?+
Will protected views toward Alexandra Palace affect my project?+
What does Haringey expect on the Harringay Ladder?+
How long does Haringey Council take to decide?+
How much do planning drawings cost in Haringey?+
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