Single Storey Extensions Liverpool

A single storey extension is one of the most popular home improvements we carry out across Liverpool, and it’s easy to see why. It’s the quickest and most cost-effective way to create a large, open-plan living space without the complexity of building upwards. Whether you want a bigger kitchen, a new family room, or a bright open-plan kitchen-diner, a single storey extension can completely change how you use your home.

At Glassar Projects, we’ve been building single storey extensions for families across Childwall, Crosby, Allerton, Aigburth, Woolton, and Mossley Hill for over 40 years. We know the local housing stock inside out, from the bay-fronted semis in Aigburth to the detached properties in Woolton, and we design every extension to suit the house it’s being added to.

Why Choose a Single Storey Extension?

A single storey extension gives you the biggest impact for the lowest cost. You only need one set of foundations and one roof, which keeps the build cost down compared to going up two storeys. Most single storey rear extensions also fall under Permitted Development rights, meaning you often don’t need to apply for full planning permission, which saves time and money.

For families in Liverpool, the most common use is creating a large open-plan kitchen-diner that opens onto the garden with bi-fold or sliding doors. It’s the kind of room that becomes the heart of the house, where the kids do their homework while you cook, and where you entertain friends at the weekend.

How Much Does a Single Storey Extension Cost in Liverpool?

We believe in being upfront about pricing. Here’s what you can typically expect to pay for a single storey extension in Liverpool:

Extension Size	Typical Cost (inc. VAT)
Small (15-20m²)	£28,000 – £35,000
Medium (20-30m²)	£35,000 – £45,000
Large (30-40m²)	£45,000 – £55,000

These prices include foundations, build, roofing, electrics, plumbing, plastering, and decoration. Kitchen fitting, bi-fold doors, and underfloor heating are extras we can quote for separately. For a detailed, fixed-price quote tailored to your property, try our Quick Quote Calculator.

Our 4-Step Process

1. Design & Planning

We visit your home, take measurements, and discuss exactly what you want. Our design team draws up plans and we handle the planning application with Liverpool City Council if one is needed. Most single storey extensions fall under Permitted Development, so this step is often quick.

2. Foundations & Structural Work

Our groundwork team excavates and pours the foundations, then builds the structural walls and installs the steel beams. This is the stage where the shape of your new room starts to appear.

3. Build & Fit-Out

The roof goes on, windows and doors are fitted, and our plumbers and electricians run all the first-fix services. Then comes the insulation, plastering, and second-fix electrics and plumbing.

4. Finishing & Handover

We handle all the decorating, fit the kitchen or fixtures if included, and give the whole space a deep clean. We walk you through everything, hand over all certificates, and make sure you’re completely happy before we leave.

Common Mistakes to Avoid with Single Storey Extensions

Over the years, we’ve seen homeowners make a few costly mistakes that are easy to avoid:

Going too small. Once the builders are in, the cost difference between a 4m and 5m extension is relatively small, but the extra space makes a huge difference to how the room feels. Don’t scrimp on size if your garden allows it.
Forgetting about natural light. A deep extension can make the middle of your house dark. We always recommend roof lanterns or skylights to keep the whole space bright.
Not thinking about heating. Underfloor heating in a new extension is cheap to install during the build but expensive to retrofit later. It’s worth considering from the start.
Ignoring the garden. Your extension will take some garden space, so think about landscaping and how the new room will connect to the outdoor area.

Neighbourhood Spotlight: Childwall

Childwall is one of the most popular areas we work in for single storey extensions. Many of the 1930s semis and detached homes have generous rear gardens, making them ideal candidates for a 5-6 metre rear extension. The typical Childwall project involves knocking through the existing kitchen and dining room to create one large open-plan space with bi-fold doors looking out onto the garden. If you’re in Childwall and thinking about extending, we’d love to come and have a look.

Frequently Asked Questions

1. Do I need planning permission for a single storey extension in Liverpool?

In most cases, no. Single storey rear extensions up to 6 metres (detached) or 4 metres (semi-detached/terraced) from the original rear wall usually fall under Permitted Development. However, if you’re in a conservation area or your property is listed, you will need to apply. We check all of this for you before we start.

2. How long does a single storey extension take?

A typical single storey extension takes 12-16 weeks from breaking ground to completion. We provide a detailed timeline before we start so you know exactly what to expect each week.

3. How much value does a single storey extension add to my house?

On average, a well-designed single storey extension adds 5-10% to your property’s value. In Liverpool, where the average house price is around £200,000, that could mean an extra £10,000-£20,000 on top of the improved living space you get to enjoy every day.

4. Can I extend to the side instead of the rear?

Yes, side extensions are a great option if you have a wide plot or a side passage. They’re particularly popular on detached homes in Woolton and Allerton where there’s space between houses. We can design a side return extension that connects seamlessly to your existing kitchen.

5. Will I need Building Regulations approval?

Yes, all extensions need Building Regulations approval regardless of whether planning permission is required. This covers structural safety, insulation, drainage, and electrics. We handle the entire Building Regulations process for you.

6. Can I have a flat roof or does it need to be pitched?

Both options work well. A flat roof with a roof lantern is the most popular choice for single storey extensions in Liverpool because it maximises internal ceiling height and lets in plenty of light. We can also do pitched roofs to match your existing house if you prefer.

Related Services

Looking for something different? See our other extension services:

Ready to Get Started?

Get a clear, instant estimate with our Quick Quote Calculator, or call us to arrange a free, no-obligation home visit.