KITCHEN
Extensions
DONE RIGHT

Specialist kitchen extension builders across Leeds. Open-plan kitchen-diners, rear wall structural alterations, RSJ beam installation — all structural steelwork handled in-house. We serve Leeds, Harrogate, Baildon, Ilkley, Roundhay, Adel and the wider Yorkshire region.

8m

Max depth — detached (prior approval)

6m

Max depth — semi / terraced (prior approval)

100%

Steel in-house — no subcontracting

Free

Site survey — Leeds

Permitted development — quick guide

Single store

Up to 4m depth — no planning needed

Standard PD. Up to 8m with Prior Approval on detached houses. Max height 4m.

Semi / terrace

Up to 3m depth — no planning needed

Standard PD. Up to 6m with Prior Approval. Party Wall Act may apply.

Open plan

RSJ beam — always required

Any kitchen-diner opening over ~1m into a load bearing wall requires structural steel. We install in-house.

All types

Building Regulations — always required

Every kitchen extension needs Building Control approval regardless of planning status.

Conservation

Additional restrictions apply

Harrogate Stray area and Ilkley — Article 4 Directions may remove PD rights. Full planning often needed.

Building Control Certified

Structural Steel In-House

Free Surveys — 24hr Response

West Yorkshire Based

Fixed Price Quotes

The Most Transformative Ground-Floor Project in Leeds

What Is a Kitchen Extension?

A kitchen extension is a structural addition built to the rear or side of your property, purpose-built to expand and transform the kitchen into the central living space of the home. It is the most consistently requested project we build across Leeds — and the one that produces the most dramatic change to daily life.

Unlike a loft conversion or garage conversion, a kitchen extension creates open, ground-floor space that connects directly to your rear garden. Combined with structural wall removal, RSJ beam installation and large glazed openings — bi-fold doors, rooflights, lantern roofs — a kitchen extension transforms the entire back of the ground floor into a single open-plan kitchen-diner-living space.

Cobin Contractors builds kitchen extensions across Leeds on detached, semi-detached and terraced properties — Victorian terraces in Leeds, Yorkshire stone houses in Ilkley and Harrogate, and suburban semis across Roundhay, Adel and Baildon. All structural steelwork is handled in-house by our own team, under one contract and one completion certificate.

01 Open-plan space connected to the garden

A kitchen extension opens the rear of your home in a way no internal remodel can achieve. Floor-to-ceiling glazing, bi-fold or sliding doors and rooflights deliver a light, airy connection to the garden that changes how the ground floor functions entirely.

02 Often qualifies for Permitted Development

03 High return on investment in Leeds

Open-plan kitchen-diners consistently rank among the most sought-after features by buyers across Leeds, Harrogate and the wider Leeds market. A well-executed kitchen extension adds both usable space and measurable market value.

04 One contractor — build and structural steel

Every kitchen extension that opens up the rear wall or removes internal load bearing walls requires RSJ steel beam installation. Cobin Contractors handles the full build and all structural steelwork — one team, one programme, one completion certificate

Extension types

Kitchen Extension Types
in Leeds

The right kitchen extension configuration depends on your property, garden size, planning position and what you want the space to achieve. Here are the four main types we build across Leeds.

01 Most common

Single Storey Rear Kitchen Extension Leeds

The most common kitchen extension type. Extends the ground-floor kitchen into the rear garden — single storey, typically flat or pitched roof. Can be built under Permitted Development on most properties, keeping the planning process straightforward. Usually involves opening up the rear wall with an RSJ steel beam to create a seamless flow between old and new space.

Permitted Development

RSJ installation

Flat / pitched roof

Open plan

02 Open-Plan Kitchen-Diner Extension Leeds

A rear extension that simultaneously removes the internal wall between kitchen and dining room, creating a single open-plan kitchen-diner-living space. Requires RSJ steel beam installation to span the new opening. The most transformative ground-floor project we build in Leeds — bi-fold doors, lantern rooflights and continuous flooring from old to new complete the space.

RSJ installation

Load bearing wall removal

Bi-fold doors

Lantern roof

03 Maximum space

Wraparound Kitchen Extension Leeds

Combines a rear extension with a side return in an L-shaped configuration — common on terraced and semi-detached houses across Leeds where the side return provides usable space that would otherwise be wasted. Structurally more complex — goalpost steel frames (two Universal Columns supporting a single beam) are typically required. The largest ground-floor footprint achievable without a planning application on qualifying properties.

L-shaped plan

Goalpost steel frame

Side return

Prior Approval

04 Side extension

Side Kitchen Extension Leeds

Extends the kitchen into an existing side return, side access or garage footprint — common on detached and semi-detached properties across Harrogate, Baildon and Adel where a side return or underused garage is adjacent to the kitchen. Often combined with a rear extension to create the full L-shaped wraparound. Side extensions over half the width of the original house typically require a planning application on most Leeds properties

Garage conversion option

Structural steel

Planning may apply

Detached properties

Note on the Government’s 2026 PD consultation: In 2026 the UK Government consulted on increasing standard Permitted Development depth limits from 4m to 5m for detached houses and from 3m to 4m for semi-detached and terraced properties. If enacted, this would allow more kitchen extensions to be built without the Prior Approval neighbour consultation process. We track planning policy changes and will advise on the current position at your survey.

Property types

Kitchen Extensions by
Property Type in Leeds

The structural and planning approach for a kitchen extension varies significantly by property type. We build across all of the following.

Detached Houses

Maximum Permitted Development Flexibility

Detached houses across Leeds, Harrogate, Ilkley and Baildon have the greatest Permitted Development flexibility for kitchen extensions — up to 4m standard PD, up to 8m with Prior Approval. No party wall implications in most cases and foundations typically straightforward on established suburban plots.

Architectural design and planning drawings — in-house
Structural engineer calculations for foundations, steelwork and roof
Planning application submission and party wall coordination
Foundations, footings and below-DPC masonry
Full cavity wall construction and RSJ steelwork
First-floor joists, roof structure and tie-in to existing
Render, brick-match or stone finish to match existing
Interior plasterwork, first and second fix, decoration

Semi-Detached Houses

Most Common in Leeds

Semi-detached houses make up a large proportion of Leeds housing stock and are well-suited to kitchen extensions. Standard PD depth is 3m, increasing to 6m with Prior Approval. Party Wall Act obligations apply if excavating within 3m of the shared boundary or affecting the shared wall — we identify this at survey stage.

Architectural design and planning drawings — in-house
Structural engineer calculations for foundations, steelwork and roof
Planning application submission and party wall coordination
Foundations, footings and below-DPC masonry
Full cavity wall construction and RSJ steelwork
First-floor joists, roof structure and tie-in to existing
Render, brick-match or stone finish to match existing
Interior plasterwork, first and second fix, decoration

Terraced Houses

Victorian Stock — Leeds Inner Suburbs

Victorian terraced houses across Headingley, Chapel Allerton, Roundhay and inner Leeds are well-suited to rear kitchen extensions. Standard PD is 3m, rising to 6m with Prior Approval. Party Wall Act implications are common on both sides — neighbouring properties on terraces are served notices before any structural work begins.

Architectural design and planning drawings — in-house
Structural engineer calculations for foundations, steelwork and roof
Planning application submission and party wall coordination
Foundations, footings and below-DPC masonry
Full cavity wall construction and RSJ steelwork
First-floor joists, roof structure and tie-in to existing
Render, brick-match or stone finish to match existing
Interior plasterwork, first and second fix, decoration

Yorkshire Stone Properties

Ilkley, Harrogate & Baildon

Stone properties across Ilkley, Harrogate and Baildon require specific expertise for kitchen extensions. We source matching Yorkshire millstone grit and Magnesian limestone from regional suppliers for external elevations. Planning authorities in Harrogate conservation areas and Ilkley require material matching — we advise and liaise with local planning officers where needed.

Architectural design and planning drawings — in-house
Structural engineer calculations for foundations, steelwork and roof
Planning application submission and party wall coordination
Foundations, footings and below-DPC masonry
Full cavity wall construction and RSJ steelwork
First-floor joists, roof structure and tie-in to existing
Render, brick-match or stone finish to match existing
Interior plasterwork, first and second fix, decoration

Planning guide 2026

Permitted Development
What You Actually Need

Planning rules for kitchen extensions in Leeds are set by national legislation — the Town and Country Planning (General Permitted Development) (England) Order 2015 (as amended) — not by Leeds City Council or Harrogate Borough Council individually. The same depth and height limits apply, with exceptions for designated land.

The most important distinction most homeowners miss: Permitted Development rights and Building Regulations approval are entirely separate requirements. PD tells you whether you need planning permission. Building Regulations tell you whether the structure is legally safe. You can build a kitchen extension under PD with no planning application — but you still need Building Control approval on every single kitchen extension.

Prior Approval (the Larger Home Extension scheme) was made permanent in 2019. It requires notification to your local authority — Leeds City Council or Harrogate Borough Council — who then consult neighbouring properties for 42 days. If no objections are raised, the extension can proceed. We manage this process for you on every kitchen extension project across Leeds.

Property Type	Standard PD Depth	Prior Approval Depth
Detached house	4m	8m
Semi-detached house	3m	6m
Terraced house	3m	6m
Conservation area	Check locally	Full planning likely

4m

Max height — single storey

Where the extension comes within 2m of the rear boundary, eaves height cannot exceed 3m. Ridge must not exceed the existing roof height.

50%

Max garden coverage rule

All extensions and outbuildings combined must not cover more than half the area of land surrounding the original house — measured from the original house footprint.

LDC

Lawful Development Certificate

Not legally required to build under PD, but strongly recommended. Formal confirmation from your local planning authority that the kitchen extension is lawful — protects you on sale and removes uncertainty with solicitors.

Structural steelwork

Structural Steelwork for
Kitchen Extensions Leeds

When a kitchen extension opens up the ground floor — removing the original rear wall or creating a large opening between old kitchen and new dining space — a Universal Beam (RSJ) is required to carry the structural load above. Any opening wider than approximately one metre into a load bearing wall requires a structural steel beam, specified by engineer calculations.

Most extension builders in Leeds subcontract structural steelwork to a separate contractor. Cobin Contractors does not. Our in-house structural team handles beam specification, calculations, installation and Building Control inspection as part of every kitchen extension project.

RSJ beam installation — any opening over ~1m

Any kitchen-diner opening into a load bearing rear or internal wall wider than approximately one metre requires a Universal Beam (RSJ). Most kitchen extensions that open up the kitchen-dining area require at least one RSJ spanning the new opening. We specify, supply and install the beam as part of the kitchen extension build — not subcontracted.

Structural calculations to Eurocode 3 standards

Building Control will not sign off structural work without a calculation pack prepared to Eurocode 3 (BS EN 1993-1-1) standards. We produce these in-house for every kitchen extension — the structural engineer calculations are included in our standard service, not an optional extra.

Goalpost steel frames for large openings

Goalpost frames — two Universal Columns supporting a single Universal Beam — are used for large rear wall openings on kitchen-diner extensions across Leeds. Common where the full rear wall of a kitchen is removed to create a wide, column-free opening onto the new extension and garden.

Padstones — load distribution into masonry

Padstones are required at each bearing end of the steel beam to distribute the concentrated load into the supporting masonry below. Size and specification are determined by the structural calculations — incorrectly specified padstones are a common Building Control failure on kitchen extensions built without proper engineering input.

Fire-rated plasterboard to Building Regulations Part B

All exposed structural steel beams inside the building must be encased in fire-rated plasterboard — typically a minimum of two layers of 12.5mm fire-rated board — to satisfy Building Regulations Part B. Building Control inspects the steel before it is concealed at the plasterboard stage.

Party Wall Act 1996 — structural implications

On terraced and semi-detached houses across Leeds, structural steelwork and foundation work near the shared boundary may trigger Party Wall Act obligations. We identify Party Wall implications at the initial survey — before you have committed to any planning or structural approach.

Building Regulations

WHAT BUILDING REGULATIONS
COVER ON A KITCHEN EXTENSION

Building Regulations are entirely separate from planning permission. Every kitchen extension in Leeds— whether under Permitted Development or full planning — requires Building Regulations approval. Here is what the key Parts cover on a typical kitchen extension build.

Part A — Structure

Foundations, load bearing walls, RSJ steel beam installation, padstones and the structural connection between existing and new. Engineer calculations required for every structural alteration. Building Control inspects the steel before concealment.

Part B — Fire Safety

Steel beams must be fire-protected with fire-rated plasterboard (minimum 2 × 12.5mm layers). Smoke detection installed to current standards. Escape routes and window dimensions checked in habitable rooms.

Part C — Damp Proofing

Damp proof course continuity between existing and new structure. Ground conditions assessed at foundation stage — clay subsoils common across Leeds require appropriate foundation depths. Contamination assessed where relevant.

Part F — Ventilation

Extract ventilation required in all kitchen extensions. Trickle vents in new window frames. Adequate fresh air provision to new and altered spaces. Whole-house ventilation strategy reviewed if the extension significantly reduces natural air infiltration.

Part H — Drainage

Roof drainage from the kitchen extension — flat roofs require adequate falls and outlet provision. Foundations must not affect existing drainage runs beneath the property. Any diversion of foul or surface water drains requires Building Control notification.

Part L — Energy Efficiency

Insulated walls, roof and floor to current U-value standards. Glazing — bi-fold doors, rooflights — managed to control heat loss. SAP assessment may be required where glazing exceeds 25% of floor area. Triple-glazed rooflights are increasingly specified in Leeds kitchen extensions for thermal performance.

Cobin Contractors submits all Building Regulations applications, coordinates Building Control inspections and manages completion certification on every kitchen extension we build across Leeds. You do not deal with Leeds City Council, Harrogate Borough Council or any Approved Inspector directly for single, double and house extesions services.

Where we Serve

Our Service areas

We build two-storey extensions across Leeds, Harrogate, Bradford and the wider Yorkshire region. Every build is managed from our base — no remote site managers, no weeks between visits.

LS1–LS29