House extension Wembley projects for ordinary houses in HA0 and HA9 often start under permitted development for modest single-storey rear work — unless you are in a Brent conservation area, caught by Article 4, listed, or a flat. GSMS Construction Ltd builds rear, side, wrap-around and double-storey extensions on a fixed-price contract after a free survey. Call 07717 790273.
- Match the extension to the stock: single-storey rear kitchen-diners on many semis in Sudbury, Preston and Tokyngton; side-return fills on tighter HA0 terraces; wrap-around where the plot and neighbours allow it.
- Brent’s Residential Extensions and Alterations SPD (January 2025) guides householder design. Sudbury Court and Wembley High Street conservation areas — with Article 4 — change the route.
- Building Regulations apply to every extension. Planning and Building Control are separate tracks.
- Fixed-price after a free survey. 5-year workmanship guarantee. In-house RC frame capability for larger structural jobs.
5-year
Workmanship
Fixed price
After free survey
HA0–HA9
Brent coverage
10–16 wks
Typical single-storey
VAT
429761270
Book a free house extension survey in HA0 or HA9.
This is the dedicated house-extension page for Wembley. For RC frame, basements and commercial work see our construction company Wembley page. Combining a loft with the ground-floor work? See loft conversion Wembley. For a published Croydon overview see house extensions Croydon.
Planning permission for a Wembley house extension
For a house extension Wembley, national permitted development rights for rear work are summarised on the Planning Portal extensions page. Depth, height, eaves and materials limits still apply. On a typical house outside designated land, a single-storey rear extension can be 3 m on a terrace or semi and 4 m on a detached house. Larger rear depths of 6 m (attached) or 8 m (detached) need the neighbour-consultation / prior-approval route and are not available on designated land.
Brent adopted a Residential Extensions and Alterations SPD in January 2025. It sits under the Local Plan and is the design guidance we read before drawings leave the office — see Brent’s Residential Extensions and Alterations SPD (PDF). Check conservation status on Brent Council’s conservation areas pages — the borough lists 22 areas, and residential ones carry Article 4 directions.
On a clean PD scheme we still recommend a Lawful Development Certificate. Where planning is required, expect Brent decision timescales that can stretch toward 8–13 weeks before you break ground. Double-storey, wrap-around and side extensions usually need a householder application.
Home extension in Wembley: types for HA0 and HA9
Wembley housing is mixed: 1930s semis, terraces around Wembley Central and Alperton, and regenerated stock near Wembley Park. The right house extension Wembley follows the plot, not a catalogue. Open a type below, or scan the cards.
01
Rear single-storey
Kitchen-diners on many Sudbury, Preston and Tokyngton semis. Slab, insulated walls, pitched tile or flat GRP with a lantern. Modest depths often stay PD outside conservation areas.
02
Side-return / wrap
Reclaim the alley, or combine side and rear into an L when the 45-degree neighbour tests allow it. SPD amenity tests matter most here. Side PD falls away in conservation areas.
03
Double-storey
Kitchen below, bedroom or bathroom above, shared foundations and roof. Usually needs planning. Typical on-site 20–28 weeks, plus 8–13 weeks if planning is required.
Single-storey rear kitchen-diners
Single-storey rear kitchen-diners
The most common ask. Open the back wall, add a concrete slab, insulated cavity walls, and either a pitched tile roof or a flat GRP roof with a lantern. Bi-folds or sliders take you into the garden. Many modest rear schemes stay inside PD outside conservation areas if they meet the 3 m / 4 m depth and height tests.
Side-return and wrap-around builds
Side-return and wrap-around builds
Side-return reclaim the alley beside many semis and terraces. Wrap-around combines side and rear into an L-shape when the plot and the 45-degree neighbour tests allow it. These are the schemes where Brent’s SPD amenity tests matter most. Side extensions are not permitted development in conservation areas.
Double-storey options in HA0 and HA9
Double-storey options in HA0 and HA9
When you need a larger kitchen below and a bedroom or bathroom above, a double-storey extension shares foundations and roof. It usually needs planning permission. Two-storey rear PD, where it exists at all, is tightly limited (typically 3 m beyond the rear wall and well clear of the rear boundary) and is often the wrong fight on a Wembley semi.
GSMS timescales for a standard single-storey rear extension are typically 10–16 weeks on site; double-storey or structurally complex work can run 20–28 weeks, with planning adding 8–13 weeks where required.
How we quote a house extension Wembley
We do not invent a Wembley pound-per-square-metre table for this page. Every quote is fixed after a free survey of structure, drainage, access, neighbours and finishes. Planning, structural-engineer and party-wall fees stay extra unless we wrap them into a managed package.
Call 07717 790273 or 07453 292996, Monday to Saturday, 9am–5pm, for the free survey.
Building Regulations and party walls
Every extension is building work. You need Building Regulations approval for foundations, structure, insulation, ventilation, electrics, drainage and fire. We coordinate inspections with Brent Council Building Control. Party wall notices follow the Party Wall etc. Act guidance on GOV.UK where the Act applies.
Structure, thermal, drainage and party wall — tap to open
Structure, thermal, drainage and party wall — tap to open
- Structure. Foundations and steels sized to the span — our in-house RC frame capability matters on the heavier jobs.
- Thermal. Walls, floors and roofs to current Approved Document L.
- Drainage. Surface water and foul connections that satisfy Building Control.
- Party wall. Notices where the Act applies on terraces and semis in HA0/HA9.
How GSMS builds your home extension in Wembley
A house extension Wembley stays on one fixed-price contract from the free survey to Building Control sign-off.
Five steps, one crew
01
Free site visit: scope, access, designation, drainage and neighbours.
02
PD, Lawful Development Certificate or householder route confirmed in writing.
03
Fixed-price contract. Structure, roof, windows, electrics and finishes itemised. VAT 429761270.
04
Build from groundworks through second fix. Single-storey 10–16 weeks; double-storey 20–28.
05
Building Control sign-off and a 5-year workmanship guarantee.
GSMS Construction Ltd is registered at Southgate N14 and already publishes Wembley HA9 coverage with HA0 Sudbury and the wider Brent radius. Hours: Monday–Saturday, 9am–5pm.
Areas we cover in Wembley
We take house extension Wembley work in Wembley Central · Wembley Park · Alperton · Tokyngton · Sudbury · North Wembley · Preston · Barn Hill · Kenton edge · Northwick Park edge.
Postcodes: HA0, HA9 — with wider Brent and North West London coverage on request. See also areas we cover.
Frequently asked questions
Open a question. These cover Brent SPD, 6 m / 8 m depths, party wall and loft-plus-extension sequencing.
Many modest single-storey rear extensions on ordinary houses outside conservation areas can be permitted development if they meet national depth and height limits. Double-storey, wrap-around, side extensions on designated land, flats, listed buildings, and homes in Sudbury Court or Wembley High Street conservation areas usually need a full application. We confirm the route on survey.
We give a fixed price after a free survey. We do not publish a pound-per-square-metre table. Structure, drainage, glazing, kitchen fit-out and whether the scheme is single- or double-storey move the figure more than the postcode.
From our Wembley construction page: a standard single-storey rear extension typically takes 10–16 weeks on site. Double-storey or structurally complex extensions can take 20–28 weeks. Planning, where required, usually adds 8–13 weeks.
It is Brent Council’s January 2025 design guide for householder extensions and alterations. Applications that need planning are judged against it — depth, height, the 45-degree neighbour tests, and how the addition reads from the street. We read it before we draw.
Yes. We sequence structure, scaffold and finishes so the two packages do not fight each other. Start the conversation on this page or the loft conversion Wembley page for your roof type.
Costs, timing and extending a house in Wembley
Usually yes in HA0 and HA9 where the new wall, foundation or roof sits on or near the shared boundary. We flag this on the free survey and can coordinate notices under the Party Wall etc. Act 1996.
Some rear PD can remain, but side extensions, cladding changes and the 6 m / 8 m larger-home route are typically off the table on designated land. Article 4 on residential conservation streets can remove further rights. We check the map before we promise PD.
Choose single-storey when the need is a kitchen-diner and the garden can spare the depth. Choose double-storey when you also need a bedroom or bathroom above and you are ready for planning. We will not upsell a second storey that the plot or the SPD will not carry.
Yes. Drawings, planning or LDC submissions, Building Regulations and party-wall coordination can sit inside one managed package.
Yes. VAT number 429761270. Quotes say where VAT applies.
Book a free house extension Wembley survey
If you want a house extension Wembley homeowners can take through Brent Council — rear, side, wrap-around or double-storey, fixed-price, on your HA0 or HA9 postcode — call GSMS Construction Ltd.
Monday–Saturday, 9am–5pm. Free survey. Fixed-price contract. 5-year workmanship guarantee.
Call 07717 790273 07453 292996 Email the survey pack
HA0–HA9. gsmsconstructionltd.co.uk