Bungalow extension: should you extend up or out?

If you want to keep everything on one level and have some outdoor space you could give up, building out for a single storey bungalow extension might be your best bet. But if outdoor space is limited, extending up might make more sense. It’s worth weighing up the pros and cons of both before you make a plan, as each will involve different amounts of building work and costs.

Here’s how the two options compare:

If you have a big garden, extending out could give you more room without changing the layout of your existing bungalow too much.

But think about how much outdoor space you're happy to lose. A rear extension might give you a lovely new kitchen-diner, but could also mean sacrificing your patio or part of the lawn.

If your garden is small or your bungalow sits close to the property boundary, building upwards could be worth exploring instead.

Like the idea of another bedroom? Or are you thinking about office space that’s separate from the rest of the house? There are lots of possibilities with roof extensions, but first you’ll need to work out whether there’s enough room – or whether your home’s structure can handle it.

The pitch of your roof and the amount of headroom available will help determine what's possible. Some bungalows have generous roof spaces, while others might need a bungalow dormer loft conversion to make the space usable.

It’s also a good idea to speak to a structural engineer as they can check whether your bungalow's walls and foundations can support another floor, and tell you if any strengthening work or reinforcements are needed.

Think about what you need the extra space for, both now and if you plan on future-proofing. If you love having everything on one level, a rear or side extension could give you more room without introducing stairs. This could be especially useful if older family members come to live with you. If this is likely, you could always look at a granny annexe if you don’t want to make huge changes to your bungalow as it is.

On the other hand, building upwards could give you the extra room you need while keeping the ground floor as it is. It could also give you a bit more separation between busy living areas downstairs and quieter spaces upstairs.

Ultimately, there's no right or wrong answer. It's about choosing a bungalow extension that works for you.

You might have lots of ideas for what you want – but factoring a budget into your plans early on will ultimately help you work out what’s achievable.

A simple loft conversion without the need for an extension or big structural changes can be a more affordable way to create extra space, but adding dormers or extending walls to create a whole new floor can ramp up costs pretty quickly.

As a guide, Checkatrade estimates that a single-storey bungalow extension costs around £1,900-£3,500 per m², while a dormer bungalow conversion can cost £40,000-£75,000.

But don’t be put off by these numbers – the amount of work needed will be unique to your bungalow and costs will vary between tradespeople, as well. Get a few quotes before deciding which option works best for your budget.

Want to extend without losing any of your garden or outdoor space? An upwards extension could be just what you need.

Your main options are:

• Loft conversion: Make use of existing roof space for an extra bedroom or home office.
• Dormer conversion: Create more headroom if your loft feels cramped.
• Second storey: Add a whole new floor if you need a lot more space.

Let’s go into more detail on each one.

If you've got enough headroom, converting your bungalow's loft could be one of the simplest ways to create more space without changing the shape of your roof.

You could use it for an extra bedroom, a home office or even a cosy guest room. VELUX roof windows can help make the space feel bright and welcoming, bringing in lots of natural light and fresh air.

Can you get into your loft but there’s not enough room to stand comfortably? A dormer loft conversion could be the answer.

A dormer extends out from the slope of your roof, creating more headroom and usable floor space, and can come in different shapes and sizes including flat-roof, pitched-roof and L-shaped designs.

While dormers usually let light in through vertical windows, the VELUX dormer has sloped windows to boost the amount of light that comes in – while still giving you the extra room you’d expect from a traditional dormer. We even have a mini dormer for smaller attic spaces.

You also have the option to combine a classic dormer with VELUX roof windows to bring in even more daylight. If you’re unsure on the best option, one of our experts would love to help.

If you need significantly more space, adding a whole new floor in a bungalow to house conversion could be worth exploring. This might involve raising or replacing your existing roof to create room for another bedroom, bathroom or living area.

It's a much bigger project than a straightforward loft conversion, though. Your bungalow's walls and foundations will need assessing, and you might need structural work and planning permission depending on your type of home and the area you’re in.

An extra floor can also completely change how your bungalow looks and functions, so think about how the new floor will fit with the rest of your home. Will you need plumbing? Where will the stairs go? There are lots of things to bear in mind which a professional builder or architect should help you with – you don’t have to work it all out on your own.

If you love having everything on one level, extending outwards could be the way to go. Depending on the space around your bungalow, there are a few ways to create more room without adding stairs or changing your roof.

Options for extending out include:

• Rear extension: Ideal for a bigger kitchen-dining room or family living area.
• Side extension: Make use of unused space next to your bungalow, such as if you have a side return.
• Wraparound extension: Combine rear and side extensions for more ground-floor space.

Let’s look at what each one involves.

Looking for small bungalow rear extension ideas? A rear extension could be a great option if you want more living space that connects to your garden. This could be a larger kitchen and dining room to fit all the family in, an open-plan living room that could accommodate a home office and play area, or just somewhere to entertain friends.

One thing to consider is how much natural light reaches into your home. VELUX flat roof windows can help bring daylight into deeper spaces – and fresh air if you choose an option that opens – making them a great choice for a flat roof extension on a bungalow where sloped roof windows aren’t an option.

Got some unused space down the side of your bungalow? A side extension could put it to good use. Depending on the layout, you could create an extra bedroom, a utility room or even a larger kitchen without taking up too much of your back garden.

You'll need to consider how close you are to your neighbours and whether extending would affect access to your driveway or garden, plus any planning permissions needed.

If you have space at the back and side of your bungalow, you could always make the most of both. A wraparound or L-shaped bungalow extension combines rear and side extensions to create a larger ground floor living area.

Think about what your priorities are and how you would use the space. If you’re just after a bit more space in your kitchen or living room and don’t want to take up valuable outdoor space, perhaps you don’t need an extension as big as this – especially as it will cost more.

But if you’ve got a growing family or you feel your bungalow is currently quite limited, the extra space could make a real difference to how you use your home (and might even add value, too).

Do you need planning permission for a bungalow extension? Not always. Some loft conversions or extensions fall under permitted development rights, meaning you might not need to apply for planning permission.

In the UK, adding a second storey can sometimes fall under these rules, although you'll need to meet the conditions set out and get prior approval from your local council.

The rules vary across the UK, so always check with your local planning authority before starting work. You'll also need to follow building regulations which cover things like structural safety, insulation and fire protection, and if you're building close to a neighbour's property, you might need a party wall agreement. Your builder or architect should be able to help you with all of this.

The cost for a bungalow extension depends on what type you go for, how much space you're adding and the work involved. Converting an existing loft can be more affordable than building out, but adding dormers or a whole new floor can push costs up.

Here's a rough guide:

*All costs sourced from Checkatrade’s 2026 guide to bungalow extensions.

*Costs sourced from MyBuilder’s guide on extension costs.

**Costs sourced from MyBuilder’s guide on attic conversion costs.

There's no one-size-fits-all answer. An extra bedroom or bathroom upstairs could make your home more appealing to buyers, while a larger kitchen, dining room or living room might be just as valuable to a family looking for more living space.

You could always ask an estate agent for advice if adding value is a priority for you – they’ll know what local buyers are looking for.

Possibly, but it depends on the project. Building upwards can create a lot of disruption to everyday life as your roof, existing rooms and hallways will be affected. Noise, dust and tradespeople going in and out of your house are a few things to consider.

Ask your builder what to expect before work begins so you can plan around the messier stages – especially if you might need to stay somewhere else for a while.

Ready to get started on your project? Before you make any big decisions, let’s recap the things worth checking:

• Your space: work out how much garden space you're happy to lose or whether there's an opportunity to build upwards.
• Your structure: ask a structural engineer or builder to assess whether your bungalow can support the changes you're considering.
• Your lifestyle: think about how you want to use the extra space, both now and going forward. Future-proofing can go a long way.
• Your budget: get a few quotes, decide what you can afford and set aside some money for any surprises along the way.
• Your permissions: check whether you'll need planning permission and what local building regulations apply.
• Your design: consider how you'll bring natural light and fresh air into your new space – a healthy home is just as important as having more space to live in.

Sometimes. In the UK, certain loft conversions and even the addition of a second storey can fall under permitted development rights, although adding a floor requires prior approval. Rules vary across the UK, so always check with your local planning authority before starting work. Once you've got a clearer idea of what's possible, you can start exploring designs that work for your home.

Want to keep reading? See how one family transformed their bungalow with an extension, the best roof windows for a home extension and the best budget-friendly window options.