
Top 5 Inspiring Single Story Extension Ideas for Your Home
A single storey extension opens up endless design possibilities, giving plenty of choice and options to design around yours and your family’s needs. We love working with homeowners to select innovative materials and unique designs that make each house extension truly one of a kind.
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Single story extension ideas
Choosing the right design can be challenging with so many options available. To spark your creativity, we’ve put together our top 5 inspiring single story extension ideas. Each idea comes with insights on planning permission, construction costs, and real design examples, proving that even small changes can have a big impact.With thousands of projects under our belt, we’re Essex Architectural designers who know a thing or two about transforming homes. Let these inspiring single story extension ideas guide you in creating a space that not only meets your practical needs but also elevates your entire living environment.
- Side - Single-story extension idea
- Cost factors for a single story side extension
- Rear - Single-story extension ideas
- Rear extension roof styles
- Wrap around - Single story extension ideas
- Kirkwood's Google reviews
- Flat roof - Single-story extension ideas
- Pros and Cons of flat roof extensions
- Pitched roof - Single-story extension ideas
- FREE House extension advice
Side - Single-story extension idea
One inspiring single story extension idea is a side extension. To achieve this, you don’t need as much space as you might think. Adding just 2–3 metres to the side of your house can create a surprisingly significant difference in your living area.
Knocking through the existing side wall not only adds extra room but also cleverly utilises the wall’s own width and length. It’s a simple, yet effective solution that often takes homeowners by surprise, proving how easily you can create that much-needed extra space.
Single story extension build costs
This approach is one of our top picks among single story extension ideas. For more guidance with build costs, click here.
Cost factors for a single story side extension
Often drainage runs parallel with the back of the house, leaving the side relatively manhole-free. This can save time and money during the build, as moving manholes usually costs between £2,000 and £3,000, depending on how many pipes are involved.
A rule of thumb in 2025 for single story side extensions is £2,000 per square metre. For example, if your extension is 3m x 6m, that’s 18m². At £2,000 per square metre, the base cost comes to £36,000, with VAT bringing the total to around £43,200.
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This single story extension idea adds valuable width to narrow houses, often transforming the home completely. A comment we frequently hear from customers after their builds are complete is that they feel like they live in a completely new house. When considering single story extension ideas, even a modest side extension can deliver dramatic results, if the architectural design is done right.
Pros and cons for single story side extension ideas
Side access
Adding a side extension can sometimes reduce or remove side access to the garden, so it’s important to weigh up how much that access matters to you. Like many single story extension ideas, side extensions can come with a few trade-offs, but the added space often outweighs the compromises.
Garden space
A key benefit of this single story extension idea is that it doesn’t cut into your main rear garden, leaving you with more space to enjoy during the summer months. The area down the side of a house is rarely used for more than storage or a walkway to the garden, making it a smart space to repurpose.
Spatial perception
Most houses are longer than they are wide, so adding a single story side extension often creates more squareness to your home. Even if the m2 area is the same, a squarer space will feel larger than a rectangle space.
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Rear - Single-story extension ideas
The most popular single story extension idea, largely due to the layout of most properties. A rectangular plot with limited side space often leaves the rear as the most practical option. Some of the finest extensions we’ve designed have been rear single story extensions, and with over 30 years of combined experience in architectural design, we’ve refined the process to a T. Let us guide you further on rear extensions, and feel free to get in touch to see if this single story extension idea is the right fit for your home.
Roof styles
The are many roof style to choose from for a single story rear extension. Some roof style will affect the price of the build and potentially the type of development consent application. We can advise more of this if you have any questions.
Rear extension roof styles - Single story extension ideas
Flat roof extensions
This used to be the cheapest roof option, but changes to building regulations have levelled the playing field. With the thermal performance requirement shifting from 0.18 W/m²K to 0.15 W/m²K, the cost of a pitched roof extension is now similar to that of a flat roof. This change forms part of the Future Homes Standard 2025. Many customers worry that flat roof extensions might feel lower in height, but by matching the existing ceiling level and incorporating skylights, the space can feel just as open and spacious as a pitched roof extension.
Pitched roof extensions
This single story extension idea works best if you’re not planning to extend beyond 3.5 to 4 metres. That’s because common clay or concrete tiles require a roof pitch of 15°, so the further the extension projects, the higher the roof will rise as it meets the existing house. A minimum clearance is needed below first floor windows, which is why a flat roof extension is sometimes the more practical choice. That said, a pitched roof extension with Velux-style roof windows can feel bright, open, and airy. If the budget allows, many of our customers say electric opening roof lights are a game changer for ventilation and ease for opening and closing.
Gable roof extensions
This extension roof idea is a pitched roof with two sloping sides that meet in the centre. It creates a triangle shaped roof with both slopes equal in pitch. The nice thing about these roofs are that they match the existing house roof style and are very spacious inside. This single story extension idea allows for plenty of natural light as the roof can consist of velux stly windows and a striking glass gable front. More costly than a flat roof and pitched roof extension due to the additional steel and timber work. the gables window also cost around £2,000.
Hipped roof extensions
A single story extension idea that typically costs £4,000–£5,000 more than a flat or standard pitched roof extension. The hipped roof design works particularly well with side return extensions, as the slopes align neatly and allow snow and rain to run off easily. Skylights along the return can bring natural light into the rear rooms of the existing house. Visually, it’s a striking roof style, and when designed by experienced local Essex architects, it can truly elevate the overall look and feel of your extension.
Wrap around - Single story extension ideas
A wraparound single story extension combines a side and rear extension to create an L-shaped space that opens up the home in an effective way. It’s a popular choice for those looking to extend the kitchen and add a dining area to create an open-plan layout.
This single story extension idea is great for making better use of the full width of the plot, especially if there’s unused space down the side. It can really change how the ground floor works day to day, without needing to move or add an extra floor.
Internal remodelling
This single story extension idea can add a significant amount of additional living space to the ground floor. With the help of experienced Essex architects and structural engineers, you can completely remodel the layout and create a new home that works for you.
Open-plan layout
Because this single story extension idea adds both width and depth, removing sections of the existing house walls creates the opportunity for a large, open-plan layout. We’ve designed many wraparound extensions where the kitchen, dining, and living areas flow together as one continuous space. A separate snug room is often included at the front of the property too, providing a quiet spot to relax when needed.
Scope for a 1st floor extension
The foundations for the side section of a wraparound extension can be designed with a future first floor in mind, ideal if you might want an extra bedroom later on. Many of the roof materials removed during the first build can often be reused for the new first floor roof, helping to reduce waste and recycle wherever possible.
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Flat roof - Single-story extension ideas
In most cases, you won’t need to apply for planning permission for a flat roof rear extension, as most fall under permitted development. But there are some exceptions to this rule, if you live in a flat, maisonette, or conservation area, you may not have permitted development rights and might need to apply for planning permission.
This single story extension idea has a more modern look, using clean lines that match the doors, windows, and walls. For more on contemporary single story extensions, take a look here.
Pros and Cons of flat roof extensions
Clean Lines and Contemporary Style
Flat roof extensions have a more contemporary and modern appearance to them. Since the regulation upgrade in 2023, the roofs are now much thicker, whereas before, flat roof extensions looked wafer-thin and lacked proper insulation. Now they have a grander look, with deep fascias creating a bold, box-style roof that adds presence and architectural interest to the rear of the home.
Everything's square
We try to cover it all when it comes to single story extension ideas, and here’s one that’s not often considered. Nearly everything within the line of sight when viewing the back of the house from the garden is square or rectangular. the doors, windows, bricks, internal and external walls, first floor windows, even the paving slabs and fence panels. A flat roof continues that same geometry, reinforcing a subtle design consistency. It’s an unspoken detail that often goes unnoticed but makes the overall design feel balanced and intentional.
Cost and install time
This is still the most cost-effective roof type on the market. Forget the old tales about flat roofs leaking, modern materials have made them some of the best-performing options for single story extensions. Their quick installation time is another major benefit, making this single story extension idea both practical and budget-friendly.
Parapet option
When tight to a neighbour who already has an extension, getting down the side to clear gutters can be awkward. A parapet wall not only adds character to the extension but also reduces the need for visible gutters. While a spigot is still required to transfer rainwater from the roof outlet to the downpipe, you won’t need gutters running around the entire roof edge. This single story extension idea works especially well for flat roof extensions and helps maintain a cleaner, more modern look.
Flat roof extension ideas - Conclusion
Flat roof single story extensions have improved a lot over the years. Better materials and smarter design have made them a popular choice for adding space without spending too much. They look modern, suit most homes, and are often quicker and cheaper to build. You might need to check them now and then for maintenance, but overall, they’re a solid option if you want more space without the big cost.
Pitched roof - Single-story extension ideas
We’ve all seen single story extensions, but not everyone has come across a vaulted pitched roof extension. The pitch refers to the angle of the roof, and in this case, it’s usually set at a minimum of 15 degrees. Pitched roof extensions are often chosen to give a more traditional look and help the new space blend in with older-style homes.
Single story kitchen extensions
Instead of building a flat ceiling inside, the modern approach is to follow the slope of the roof with plasterboard and add Velux-style windows. This makes use of the full height, bringing in more natural light, especially helpful if it a kitchen extenson. In our opinion, it’s the only way to do it.
Why choose a pitched roof?
If you’re after a solid all-round option when comparing roof extension types, a pitched roof single story extension is hard to beat. It’s one of the cheaper options, goes up quick, and with a vaulted ceiling inside, it feels light and spacious.
Here’s a few reasons why we rate pitched roof single story extension ideas so highly for homeowners planning with experienced architectural designers.
A natural fit for traditional architecture
Pitched roof extensions are a natural fit for traditional-style houses. Their classic shape helps the new space feel like it’s always been part of the home. They’re also often preferred by planning departments, as they help maintain the overall character and style of the neighbourhood.
Strong and weather-resistant roof extension type
Pitched roof single story extension ideas are known for their durability. Their angled design helps water drain off easily, reducing the risk of leaks and long-term damage. As one of the most reliable roof extension types, they hold up well in tough weather conditions and are a popular choice among Essex architects for long-lasting home extensions.
Brighter Spaces with Natural Light
The pitch of the roof makes it easy to add roof windows, which bring loads of natural light into the room. It makes the space feel bigger and brighter, and helps create a nicer place to spend time. It's one of the big plus points of pitched roof single story extension ideas.
Room for Proper Insulation
Pitched roofs have more space to add thicker insulation. This helps keep the warmth in, lowers energy bills, and makes the extension more comfortable all year round. Another reason pitched roof single story extension ideas are a smart choice.
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