L-shaped extensions in Nottingham
An L-shaped extension is a single-storey build that fills the side return and extends across the back of the house, so the new room turns the rear corner of your home. Getting one right is mostly a design job: deciding which arm of the L holds the kitchen, how the roof is built where the two arms meet, and how daylight still reaches the middle of the house.
This page covers those design choices. For planning rules, structure and whether a wrap-around suits your house at all, start with our wrap-around extensions guide.
- Layout zoning planned around the corner
- Roof options compared: flat, valley or glazed
- Free site survey and a written, itemised quotation
Two arms and a corner
Every L-shaped extension has three parts. The rear arm runs across the back of the house and out into the garden. The side arm fills the side return, the strip of land beside the back of the house that often holds bins, a path or a narrow patio. The corner is where the two meet, just beyond the original rear corner of the building.
Each part does a different job. The rear arm usually gets the widest opening to the garden. The side arm is long and narrower, which suits a run of kitchen units, a utility or a WC. The corner is the natural centre of the plan, so it is often where the dining table ends up.
Thinking about the space this way, rather than as one big box, is what stops an L-shaped room feeling like a corridor with a kitchen at the end.
Best for
Semi-detached, detached and terraced homes with both a back garden and a side return or side passage going spare, where the aim is one connected kitchen, dining and family space.
Typical time on site
Around 10 to 16 weeks once work starts, depending on size, ground conditions and finish. This is an indicative range, not a guarantee, and design and approvals come first.
Where the kitchen, dining and living areas go
There is no single right layout. These are the arrangements that come up most often at survey, and what each one suits.
Kitchen in the side arm
A long run of units or a galley kitchen fills the side arm, the dining table sits at the corner and the sofa area faces the garden in the rear arm. It suits long, narrow side returns and keeps cooking out of the main sightline from the garden doors.
Kitchen across the rear
The kitchen and island face the garden in the rear arm, and the side arm becomes a utility, boot room, pantry or downstairs WC. It suits families who want a clear kitchen-diner and somewhere to keep laundry and muddy shoes out of view.
A separate snug in the side arm
Kitchen and dining share the rear arm, while the side arm is a snug, playroom or home office that can be closed off with sliding or pocket doors. It suits households who want open plan most of the time and a quiet room some of the time.
- Keep wet rooms near existing drains. Sinks, dishwashers and WCs placed close to the existing soil stack usually mean less drainage work.
- Protect the route to the garden. Plan a clear walkway from the hallway to the garden doors so people don’t cut through the cooking zone.
- Decide what happens to the middle room. The original back or dining room can join the open plan or stay as a separate room. That choice affects steelwork, heating and where light comes from.
- Think about the loss of side access. Filling the side return often removes the only outside route to the back garden, so bins and bikes may need to come through the house or a gate elsewhere.
Roof options at the corner
The roof is where an L-shaped extension differs most from a simple rear extension, because two roof areas have to meet each other and the existing house.
Flat roof across the whole L
One continuous flat roof covers both arms, with a roof lantern or rooflights where light is needed. It gives the simplest junction at the corner and a clean ceiling inside. The roof build-up has to fit below the upstairs window sills, and falls must be planned so water drains to outlets rather than pooling at the corner.
Pitched roofs meeting in a valley
Each arm gets its own sloping roof, usually tiled to match the house, and the two meet at the inside corner in a valley. It can suit the look of a traditional house. The valley needs careful detailing because it collects water from both slopes, and the extra height of a pitched roof matters where the extension is close to a boundary.
Glazed roof over the side arm or corner
A glass roof or a run of rooflights sits against the old house wall, over the side arm or the corner. It sends daylight into the middle of the plan. Consider solar gain in summer, glare on screens and worktops, blinds and cleaning access. Building Regulations limit how much glazing an extension can have unless the design compensates elsewhere, so a lot of roof glass may need extra calculations.
Getting light into the middle of the house
An L-shaped extension can make the centre of your ground floor darker if nobody plans for it. Filling the side return usually covers the side window of the original middle room, and the rear arm moves the back wall and its glazing further away.
The usual fixes are overhead. A strip of rooflights along the side arm, right against the old house wall, lets light fall into the room that lost its window. A lantern over the corner puts light above the dining table, where people sit longest. Wide glazed doors in the rear arm bring light in from the garden side.
Inside, keeping sightlines open through the middle of the plan and using glazed internal doors helps light travel further. We look at which way the garden faces and where the sun falls through the day before recommending where the glazing should go.
Worth checking at your survey
- Which way the rear of the house faces
- Where the existing soil stack and drains run
- Height to the upstairs window sills
- How close the side arm will be to the boundary
How an L-shaped extension is designed and built
Free site survey
We measure up, check the boundary, drains and window heights, and talk through how you want to use each part of the L.
Layout and roof options
We draw the layout zones and show the roof options for the corner, so you can compare them before anything is fixed.
Planning route
We check whether the design may fall under permitted development or needs a householder application, and prepare the drawings for whichever applies.
Structure and Building Regulations
A structural engineer designs the steelwork where the old rear and side walls are opened up, and the drawings go to building control.
Groundwork and drainage
Footings are dug around the corner, drains are diverted or protected, and the floor slab goes in for both arms.
Shell and roof
Walls, steels and the corner roof go up, followed by lanterns, rooflights and doors, until the shell is watertight.
Fit-out and handover
Plastering, electrics, plumbing, flooring and any kitchen or joinery are completed, then we snag and hand over the certificates.
L-shaped extension costs
Indicative guide ranges for 2026, not quotes. Every house is different, so you get a written, itemised quotation after the survey.
| Project size | Typical footprint | Indicative guide range |
|---|---|---|
| Compact L-shaped | Up to 20 sqm | £42,000 – £58,000 |
| Standard L-shaped | 20 – 30 sqm | £58,000 – £78,000 |
| Large L-shaped | 30 – 40 sqm | £78,000 – £100,000 |
| Premium finish | 40 sqm plus | £100,000 + |
Ranges cover structure and shell. Kitchen units, high-end glazing and bespoke finishes are priced as separate lines in your quotation, so you can see where the money goes. On an L-shaped build, the corner roof type, the amount of roof glazing, the steelwork at the old rear corner and any drain diversions in the side return are the items that move the price most.
Planning and Building Regulations, in brief
An L-shaped extension is checked against both the rear and the side extension limits of permitted development, and it has to satisfy both. Some single-storey designs may fall under permitted development, depending on the property and any local restrictions, but many need a householder planning application. Your property needs to be checked before you rely on either route.
- Side arm: single storey, no more than 4m high and no wider than half the width of the original house under permitted development. Side extensions are not permitted development in conservation areas and other Article 2(3) land.
- Rear arm: up to 3m deep on attached houses or 4m on detached houses, or more through the prior approval route, and no more than 3m to the eaves within 2m of a boundary.
- Building Regulations approval is needed either way. It is separate from planning and covers structure, drainage, insulation, ventilation and fire safety.
- Party Wall etc. Act 1996: building on or near a shared boundary, or digging foundations close to a neighbour’s, can mean serving notice first.
Listed buildings, Article 4 directions and past planning conditions can all change the answer. Our wrap-around extensions guide covers planning and structure in more depth.
We handle the paperwork
We can prepare the drawings for a lawful development certificate or a householder application, and coordinate the Building Regulations submission and inspections.
See the work before you decide
Photos tell you more than a paragraph of promises. Our project gallery is organised by extension type, so you can look at finished work before you book a survey.
Our reviews page explains how we check feedback: a review is only published once it has been matched to a real job. That is also why you won’t find anonymous testimonials on this page.
Ask for a reference
At your site survey, ask us for a past customer with a similar L-shaped extension you can speak to. It’s the most direct way to hear how a project ran from someone who lived through it.
L-shaped extensions across Nottingham
Not sure if we cover your street? Get in touch and we will let you know.
L-shaped extension questions
An L-shaped extension is a type of wrap-around extension. Both fill the side return and extend across the rear. People often use the terms to mean the same thing, though wrap-around can also describe two-storey designs or ones that reach further around the house.
It depends on the house and how much height you have. A flat roof with a lantern gives the simplest corner junction. Pitched roofs meeting in a valley can match a traditional house but need more height and careful detailing. A glazed roof over the side arm brings the most light into the middle of the plan but needs thought about heat, glare and Building Regulations glazing limits.
It can, if the design ignores it. Filling the side return usually covers the middle room’s side window. Rooflights along the old house wall, a lantern over the corner and open sightlines through the plan are the usual ways to bring light back in.
Commonly either along the side arm, with dining at the corner and living in the rear arm, or across the rear arm facing the garden, with a utility or WC in the side arm. Keeping sinks and WCs near the existing drains usually saves drainage work.
Our indicative guide ranges run from £42,000 to £58,000 for a compact build up to around £100,000 or more for large or premium projects. These are not quotes. You get a written, itemised quotation after a free site survey.
Around 10 to 16 weeks on site is typical once work begins, depending on size, ground conditions and finish. Design, any planning application and Building Regulations approval come before that, so we give you a realistic timeline with your quotation.
Possibly. Some single-storey L-shaped extensions may fall under permitted development, depending on the property and any restrictions, but because the side and rear parts must both meet their limits, many need a householder application. We check your property before any drawings are finalised.
Plan your L-shaped extension with a free survey
Book a free site survey. We will check the drains, window heights and boundary, sketch the layout options for your corner and give you a written, itemised quotation.