Thinking about a single storey kitchen extension in London? It can really change how your home feels and works, but getting a handle on the construction timeline is honestly crucial if you want to stay sane along the way.
Most projects like this in London take about 12-16 weeks from start to finish. If your design is complicated or you hit planning snags, it can take longer.
Your extension project comes in stages: planning, getting permissions, laying the foundation, actual building, and finally, all the interior finishing touches.
London’s building rules and planning hoops add their own twist, so your timeline might shift depending on those.
This guide breaks down each step—design, permits, and what happens each week on site.
You’ll pick up tips on working with London’s planning system, making the most of natural light, and what to expect as the build moves forward.
Key Takeaways
- Single storey kitchen extensions in London usually need 12-16 weeks if you plan well and follow the rules.
- Getting a good result depends on smart design, locking in the right permissions, and hiring experienced local contractors.
- Your timeline might shift if your design is tricky, the weather’s bad, or you run into planning or contractor delays.
Understanding Single Storey Kitchen Extensions
Single storey kitchen extensions add extra living space at the back, side, or both, helping you get more out of your London home. You can usually do this within permitted development rights, but the setup you choose changes what’s possible.
What Is a Single Storey Kitchen Extension?
A single storey kitchen extension means adding more room to your kitchen at ground level. You’re expanding outwards, not upwards.
This often opens up your kitchen into a bigger kitchen-diner or even a kitchen-living space, which can totally change how you use your home.
Because you’re staying at ground level, the build is simpler than adding another floor. Most times, you can do this under permitted development rights, which keeps things a bit easier.
The new bit connects directly to your old kitchen, so you get a smooth flow from old to new. Lots of people also knock through internal walls to make one big living space.
In London, these extensions have really taken off. Space is tight and property prices are high, so adding a ground floor extension is often the most practical way to get more space without moving.
Types: Rear, Side, and Wraparound Extensions
Single storey rear extensions stick out from the back of your house. They’re the most common type. Under permitted development, you can go out up to 6 metres if you’re in a terrace or semi, or 8 metres if you’re detached.
Rear extensions are great for making kitchen-dining spaces that open right onto the garden. It makes everything feel bigger and lighter.
Single storey side extensions push out into the side of your garden or the side return. If you’ve got a Victorian terrace, a side return extension can reclaim that wasted strip of land.
Side extensions can’t be more than half the width of your house, and they can’t go higher than 4 metres if you want to stay within permitted development.
Wraparound extensions combine both rear and side extensions, creating an L-shape. They give you the most space, but they’re more complicated and cost more to build.
Key Benefits for London Homes
Single storey kitchen extensions help you beat London’s space crunch without the hassle of moving. You get more room, and you don’t have to pay stamp duty, estate agent fees, or removals.
Done right, these extensions usually add more value than they cost. Some studies say a well-designed kitchen extension can boost your home’s value by 15-20% in London.
Improved functionality is a big win too. You can turn a cramped Victorian kitchen into a modern family hub with space to cook, eat, and hang out together.
Big windows and doors flood the ground floor with natural light. When you open up to the garden, the line between inside and outside blurs in a really lovely way.
Everyone gets more space for their own thing—kids can play, adults can cook or work, and you can all be together without feeling on top of each other.
Planning Your Single Storey Kitchen Extension Project
If you want your kitchen extension to go smoothly, you need clear goals, a realistic budget, and good professionals from the start.
Defining Goals and Requirements
Start by figuring out exactly what you want from your kitchen extension. Do you need more cooking space? A bigger dining area? Easier access to the garden?
Write down your requirements. List things like where appliances will go, how much storage you need, and how many people you want to seat.
Look at what’s not working in your current kitchen. Is it too dark? Not enough storage? Too cramped? Nail down the problems so you can solve them with your new design.
Think about how the new space will connect to what’s already there. The best extensions let you move easily between old and new spaces, so plan out sight lines and how you’ll walk through the rooms.
Check for any structural issues early on. Load-bearing walls, drains, or awkward utility connections can limit what you can do. A professional survey can spot these before you get too far with design.
Setting Your Budget and Extension Costs
Single storey extension cost in London usually falls between £1,800-£3,000 per square metre. Kitchen extensions cost more because of all the specialist work and fancy finishes people want these days.
Basic extensions start around £2,500 per square metre, but if you go for high-end stuff, you could be looking at £3,500 or more per square metre.
| Cost Component | Percentage of Budget |
|---|---|
| Construction | 60-70% |
| Professional fees | 15-20% |
| Contingency | 10-15% |
Single storey kitchen extension budgets should also cover:
- Kitchen units and appliances
- Upgrades to electrics and plumbing
- Flooring and tiling
- Building control fees
Add a 10-15% contingency just in case. Unexpected structural issues or planning hiccups can pop up and bump up the price. Getting a quantity surveyor involved can help you nail down a more accurate estimate, especially for trickier jobs.
Engaging Architects and Designers
Pick architects who know London homes inside out. Local experience with planning and building regs is a huge bonus for kitchen extensions.
Ask to see their previous projects. You want someone who’s designed bright, practical spaces like the one you’re imagining. Don’t forget to check references and accreditations.
Be upfront about fees. Architects usually charge 10-15% of the build cost, but some offer fixed prices for standard extension designs.
Give your design team as much detail as you can. The more they know about your needs and how you live, the better the design will fit you.
Expect to go through a few design drafts. The first idea rarely ends up being the final plan, so allow time for tweaks and feedback from planning officers.
Navigating Permission and Regulations in London
In London, single storey kitchen extensions mean dealing with planning permission, building regs, and sometimes chatting to neighbours. Knowing the rules up front can save you a ton of hassle later.
Planning Permission Requirements
Lots of single storey kitchen extensions fall under Permitted Development Rights (PDR), so you might not need full planning permission. If your extension doesn’t go more than 6 metres out the back (terrace or semi) or 8 metres (detached), you’re probably okay.
The max height is 4 metres, and you can’t cover more than half your garden or stick out past the side of your original house.
PDR doesn’t apply if your place is:
- Listed or in a conservation area
- A flat or maisonette
- Already extended under PDR before
If you’re in an Article 4 Direction area, permitted development rights might be limited or gone altogether. Always check with your local council before you get too excited.
If your plans don’t meet PDR rules, you’ll need full planning permission. That usually takes about 8 weeks and means submitting detailed drawings and consulting with neighbours.
Building Regulations Compliance
Every single storey kitchen extension needs building regs approval, even if you don’t need planning permission. These rules cover stuff like safety, insulation, and making sure everything’s up to scratch.
Some of the main building regs you’ll deal with:
- Proper foundations and structural calculations
- Insulation in walls, floors, and roofs
- Windows and doors that meet thermal standards
- Electrics that follow Part P
You’ll need to submit your plans to the council’s building control team or hire an approved inspector. Sometimes inspectors get things done a bit quicker.
Building control comes out to check things at key stages—foundations, damp-proofing, and when it’s all done. Book them at least 48 hours ahead to keep your build on track.
If you don’t meet the regs, you could get hit with enforcement notices and have to redo work. It’s just not worth the risk, so always use qualified pros who know the latest standards.
Party Wall and Neighbour Considerations
If you’re building within 3 metres of a neighbour’s boundary and your extension goes deeper than their structure, you’ll need a party wall agreement. This legal step helps protect your neighbour’s property from damage.
Send formal party wall notices at least 2 months before starting construction. Neighbours have 14 days to respond, either agreeing or raising concerns.
Party wall processes usually involve:
- Condition surveys of neighbouring properties
- Appointing party wall surveyors if there’s a dispute
- Agreeing on construction methods and access
It’s wise to consider neighbour relations beyond the legal side. Let nearby residents know about construction schedules, expected working hours, and possible disruptions.
Most London boroughs limit construction hours to 8am-6pm Monday to Friday and 8am-1pm on Saturdays. Sundays and bank holidays are generally off-limits, but always check your borough’s specific rules.
Keep communication open during the build. If neighbours have concerns, address them quickly to keep things friendly and avoid complaints to the council.
Step-by-Step Build Timeline for a Single Storey Kitchen Extension
Most single storey extensions in London take about 12-16 weeks to build. The whole thing moves from groundwork through structure to interior finishing, with clear steps along the way.
Initial Site Preparation
Your builders will show up in weeks 1-2 and start with essential groundwork. They’ll set up site facilities, mark out where the extension goes, and sort access for vehicles.
Site setup typically includes:
- Getting temporary utilities and welfare facilities in place
- Putting up safety barriers
- Digging foundations and levelling the ground
- Setting up spots to store materials
They’ll also handle any demolition—like knocking down walls where the extension joins your house. Drainage checks and utility diversions usually happen at this stage.
Bad weather can slow this down, especially in winter when frozen ground makes digging tough. Sometimes you’ll lose a few days here.
Construction Phase Breakdown
Weeks 3-11 cover the main build, moving from foundations to a weatherproof shell.
Weeks 3-4: Foundation and groundwork
- Poured and cured concrete foundations
- Installed damp-proof course
- Connected drainage
- Laid insulated ground floor slab
Weeks 5-7: Structure and envelope
- Built external walls
- Put up internal partitions
- Carpenters erected the roof structure
- Installed roof membrane and tiles
Week 8: Weatherproofing
- Fitted windows and external doors
- Made the extension watertight
Weeks 9-10: First fix services
- Ran electrical, plumbing, and heating systems
- Opened up to the existing house
- Installed steel beams if needed
Week 11: Plastering
- Completed wall and ceiling plastering
- Allowed a week for drying
Timelines and Key Milestones
Second fix work happens in weeks 12-14, turning the shell into a usable kitchen.
Critical milestones:
| Week | Milestone | Significance |
|---|---|---|
| 4 | Foundations complete | Structure can begin |
| 8 | Weatherproof shell | Services installation starts |
| 10 | House connection | Full structural integration |
| 11 | Plastering finished | Second fix work begins |
| 14 | Practical completion | Extension ready for use |
Final phase activities:
- Installed kitchen units and worktops
- Made sockets and lighting live
- Connected plumbing fixtures
- Laid flooring throughout
Two-storey extensions usually need 3-5 more weeks than single storey ones. If your design is complex or uses a lot of steelwork, it might add another 2-4 weeks.
Snagging—finding and fixing any last-minute issues—takes 1-2 weeks before you get the final handover.
Designing for Natural Light, Insulation, and Energy Efficiency
Getting the natural light and insulation right makes your kitchen extension more comfortable and energy efficient. A good balance keeps the space bright and helps lower heating bills.
Maximising Natural Light
Design your extension with natural light in mind. Place big windows on south-facing walls to catch the most daylight.
Bi-fold doors opening to the garden can really open things up, letting in loads of light and making the space feel bigger. They often stretch across whole walls, blurring the line between inside and outside.
Roof lights and skylights are perfect for single storey extensions. Put them over worktops or dining tables—anywhere you’ll spend time. Velux windows are reliable and can be fitted with electric openers if you want that extra convenience.
Consider glazed doors between your extension and the rest of the house. They let light flow through but still give you the option to close things off if you need to.
When sizing windows, balance the need for light with the risk of heat loss. Triple-glazed units insulate better than double-glazing and still let in plenty of light. Slim aluminium frames mean you can have bigger panes with less visual clutter.
Try to position windows so you’re not looking straight into a neighbour’s house. High-level glazing keeps things private but still lets in the sun.
Insulation Choices and Energy Efficiency
Your insulation choices will affect comfort and running costs for years. Go beyond the minimum building regs for wall insulation if you want the best results.
Common insulation materials:
- Rigid foam boards: Great for tight spaces, solid thermal performance
- Mineral wool: Budget-friendly, good for sound and heat
- Natural fibres: Sheep’s wool or cellulose if you want a greener option
Floor insulation stops heat escaping into the ground and keeps cold spots at bay. Install it between joists or under concrete, depending on your foundation.
Pay close attention to roof insulation to avoid thermal bridges. Use continuous layers across the ceiling, or try a warm roof system with insulation above the deck to block out cold spots.
If you’re aiming high, shoot for U-values around 0.15 W/m²K for walls and 0.13 W/m²K for roofs. That’s better than standard regs and will save you money on heating.
Don’t forget air tightness. Seal up gaps around windows, doors, and pipes during the build to make sure your insulation actually works.
Roof Options and Interior Finishes for Kitchen Extensions
Your choice of roof shapes the look and structure of your extension, while interior finishes bring the space to life and make it work for you.
Selecting the Right Roof: Flat vs. Pitched
Flat roofs are usually the cheapest for single storey extensions. They’re great for modern designs and won’t block views from upstairs rooms.
Modern flat roofs need good drainage and quality membranes to avoid leaks. You’ll also need ventilation—usually a 10mm gap at the eaves—to meet building regs.
Pitched roofs drain rain better and often get planning approval more easily. They suit older houses and can include skylights or roof windows for extra daylight.
Gabled roofs look striking from outside, while mono-pitched designs give a sleek, modern vibe. Both cost more than flat roofs but generally last longer and handle weather better.
Think about what fits your house, the local planning rules, and your budget. Pitched roofs blend in with period homes, while flat roofs suit contemporary extensions.
Final Interior Fit-Out and Decoration
Once the structure, plumbing, and electrics are sorted, kitchen fit-out can start. This bit usually takes 2-3 weeks, depending on how fancy your kitchen is.
Flooring goes down first. You might choose:
- Big tiles for a seamless look inside and out
- Engineered wood for a cosy, classic feel
- Polished concrete if you like it industrial
- Underfloor heating if you’re feeling fancy
Kitchen units come next. Fit the base units, template and install the worktops, then add wall units, appliances, and connect the plumbing.
Finish up with decoration. Paint the walls, put up splashbacks, and add trims. Lighter colours help make the space feel bigger, especially if you’ve got lots of glass letting in daylight.
Final touches are things like lighting, door handles, and storage. Give everything a once-over to make sure it all works before you sign off.
Frequently Asked Questions
Building a single-storey kitchen extension in London has its own stages, material needs, and planning hoops to jump through. The job usually takes 3-4 months and calls for solid project management if you want things to run smoothly.
What are the key stages involved in constructing a single-storey kitchen extension?
The process starts with digging and pouring foundations to the right depth, following building regs.
Next, you’ll build the structural frame—put up walls, get the roof on, and make sure there’s a proper damp-proof course.
Then comes weatherproofing. Fit the roof, windows, and external doors to keep the rain out before starting inside.
Internal work has its own order: electrics and plumbing first, then insulation and plasterboard.
The last bit covers plastering, laying floors, and fitting the kitchen. Decorating and final electrical jobs wrap things up.
How much time is typically required to complete a kitchen extension?
Most single-storey kitchen extensions take 3-4 months if everything goes to plan. That’s for standard sizes and straightforward designs.
Delays can happen, though. Material shortages, bad weather, or busy contractors might add a few weeks.
Getting planning permission can tack on another 6-8 weeks. You’ll also need to book building control inspections at key stages.
If your design is complex or the extension is larger, it could take 5-6 months. Major structural work or moving utilities tends to slow things down, too.
Which materials are essential for building a kitchen extension and where can they be acquired?
You’ll need foundation materials like concrete, steel reinforcement bars, and damp-proof membranes. Builders’ merchants or specialist concrete suppliers around London usually carry these.
For the structure, think bricks or blocks, cement, sand, and roof timbers. Most builders’ merchants have these, but sometimes you have to order certain bricks ahead of time.
When it comes to the roof, you’ll want tiles, felt, battens, and guttering systems. Honestly, specialist roofing suppliers tend to offer better deals if you go for a full roofing package.
Insulation matters a lot for building regulations. Wall, floor, and roof insulation are best sourced from specialist suppliers.
Inside, you’ll need plasterboard, electrical cables, plumbing bits, and flooring. Many suppliers set up trade accounts, which can save you a chunk if your project is on the larger side.
What planning considerations must be addressed prior to the construction of a single-storey kitchen extension?
Planning permission depends on your extension’s size and where it’s located. Some extensions fall under permitted development rights, so you might skip the formal application.
You’ll need building regulations approval for every extension, no exceptions. This means submitting detailed plans with your structural calculations, insulation details, and ventilation specs.
If your extension affects neighbouring properties, you might need a party wall agreement. It’s on you to notify adjacent owners before you start building.
Plan utility connections early. Contact gas, electricity, and water providers ahead of time to set up new connections or move existing ones.
Access can get tricky in London’s packed neighbourhoods. Figure out how you’ll handle deliveries, waste removal, and where contractors can actually park.
Can you outline a basic project management approach for overseeing a kitchen extension build?
Kick things off with a timeline that breaks down each phase and includes some buffer for delays or bad weather. You never know when things will go sideways.
Order materials so they show up right before you need them. That way, you avoid clutter and lower the chance of stuff getting stolen or damaged on site.
Book building control inspections at the right stages and try to get them scheduled early. Inspection delays can really mess with your momentum.
Keep in touch with contractors and suppliers. Weekly progress chats help you spot problems before they get out of hand.
Stay on top of quality throughout the build. Pop by the site regularly so you can catch and sort out any issues as soon as they crop up.
What are some critical dos and don’ts to keep in mind when extending a kitchen in a single-storey house?
Do make sure you get waterproofing right during construction. Install damp-proof courses carefully, and use breathable membranes in the roof.
Plan for good ventilation in your new kitchen. Building regulations actually require certain ventilation rates for cooking spaces, so don’t ignore that.
Don’t cut corners on foundation depth or the specs. Solid foundations keep your structure safe and compliant with building regs.
Don’t skip building control inspections just to save a bit of time. If you miss those, you might face costly fixes down the line.
Do think about how the extension connects with your existing house. Make sure the new work ties in well with drainage and utilities.
Don’t overlook access routes. Give workers safe ways to get in and out, and leave enough space for storing materials during the build.
