Small house extension ideas: 13 ways to stretch your space

Small house extensions can add plenty of space and value to your home. So, if you have little room or budget for a larger project, here's how to get your small extension to make a big impact

Small house extension: a glazed walkway between a converted garage and house

Small house extensions make a great alternative if you lack the space or budget to add a large extension to your home. A modest, but well-designed addition can be transformative, changing the aspect of a room, bringing in valuable extra daylight, linking existing spaces or improving circulation and flow. Whether you're adding a porch or a modest loft extension, a small single storey extension or a side return extension, you can add both value and space to your home if you get it right. These small extension ideas will get you started.

Find much more advice on extending a house in our ultimate guide.

How much do small house extensions cost?

You can expect to pay from £900 to £3,000 per m² depending on location, specification and scale. For a good idea of the cost of your small extension, check out our extension cost calculator.

It's worth noting that smaller single storey extensions tend to be proportionally more expensive than double storey extensions because of fixed costs such as planning and design, building regulations fees and the fact that there are no economies of scale. This said, they are a worthy investment if their addition will transform the feel of your space. 

Whether you want to maximise loft space with a loft conversion or add more living space downstairs with a basement conversion, we've got all the advice you need. Or perhaps you want to up the square feet at the front of your house by adding a porch or bring more light into your home and connect to the garden by building an orangery, the options are abundant.

1. Create space by adding a porch

Adding an enclosed porch can act as a useful buffer to the elements, especially if your front door opens directly into a living room or you'd like to make a small hallway feel more spacious.

Small house extension: a large porch and lobby; by Gemma Medden and Gareth Fisher's extended cottage in Hornby, North Yorkshire

(Image: © Katie Lee)

2. Add a box dormer to create more full-height space

If you've inherited a loft conversion from a former owner and are dissatisfied with the amount of full-height space, a box dormer is an easy solution that promises to transform the feel of your loft. It can be especially useful in providing the headroom needed to add stairs into a loft (1.9m minimum at centre) or for a loft bathroom.

terraced house with small house extension at the side and box dormer

(Image: © Alison Hammond)

3. Add a living room extension

Extensions that add only a metre or two in width can’t usefully form a living room in their own right, so it is often best to use the space to extend an existing room, linking old and new with as wide an opening as possible. The exception is if the space is used as a cloakroom or utility room.

living room extension with skylights images by leanne dixon

(Image: © Leanne Dixon)

4. Connect your home to a converted garage with a covered walkway

A covered walkway linking a house to an outbuilding, such as a garage conversion, can be very successful. A glazed walkway can be a great solution to planning restrictions – for example, a listed building, where a solid link would be inappropriate.

Small house extension: a glazed addition between two solid wall extensions

(Image: © Brent Darby)

5. Transform a dark basement with a lightwell

Adding a small glazed extension to the back of a basement conversion will flood the space with light, helping it appear larger and lighter. The extension needs only to be modest in scale and works well if it opens onto a sunken courtyard, with stairs up to the garden.

home exterior with large lightwell by james balston

(Image: © James Balston)

6. Add a bay window extension

A projecting bay window extension can enlarge a room and does not necessarily require foundations – it can be cantilevered on brackets from the existing structure. Windows on three sides also bring in extra light, enhancing the spacious feel of a room.

exterior shot of a house with small house extension: a bay window extension photo by adam carter

(Image: © Adam Carter)

7. Fill in with a side return extension

Many terraced and semi-detached homes have a small outdoor area behind and at the side, called the side return. Filling the space with a single-storey extension is a great way to increase the size of a kitchen, making it better suited to become an open plan kitchen living and dining room

Find out more about adding a side return extension, and take a look at our gallery of Victorian terrace extensions for inspiration. 

Side return small house extension exterior

(Image: © Tim Mitchell)

8. Add a lean-to conservatory 

An addition that can be built (subject to size and design) without planning permission or building regulations consent, building a conservatory is a great way to create an additional living room. To use it all year round, you will need to invest in heating and conservatory blinds.

Find out more about building a conservatory in our guide. Use our guides to planning permission and building regulations for more information about any other extension type you'd like to build.

garden room conservatory with wicker chair and dining room

(Image: © Jo Sheldrake)

9. Build an orangery

Adding an orangery is the perfect balance between building an extension and conservatory. With areas of solid walls and solid roof with a glazed roof lantern, it is better insulated than a conservatory and is easier to control the temperature. See our guide for lots more information.

Small house extension: an orangery attached to period property by anglian home improvement

(Image: © Anglian Home Improvement)

10. Add an oak frame extension

There are many modular extension systems that offer a design-and-build solution for a new room. An oak frame extension is a more traditional option – a single room with a pitched roof featuring a vaulted ceiling with exposed trusses.

oak frame extension with vaulted ceiling and exposed beams by border oak

(Image: © Border Oak)

11. Build a small glazed extension

Whether you're planning to build a single storey extension into a side return or across the back of your house, adding in a large expanse of glazing into your design will ensure your newly expanded room is flooded with light all year round. 

Suited to both contemporary and period homes, glass extensions are governed by building regulations, although you may not need planning permission. Find out all you need to know in our guide to adding a glass extension.

A glass small house extension by Yard Architects

(Image: © Richard Chivers)

12. Add a small house extension at the rear

Adding a single storey extension at the rear of your property can totally transform your home. It might be that it allows you to have a larger kitchen diner or living space. 

Or, let's say you have a kitchen running across the back of your house and you extend 2m out into the garden; you then build a partition wall at the back end of the original kitchen to create a room in (effectively) the middle of the house that's 1m to 2m deep. In that small, dark space, you can put utilities, whether a utility room or cloakroom, while your kitchen sits within the garden end of the original room plus the new extended space. You sensibly put rooflights into the roof of the small extension to make your new kitchen lighter and brighter than the new room, plus of course with the new utility space behind it, you've freed it up of all the laundry space and extra storage space you might have needed before. 

Use our guides to adding a single storey extension and planning a utility room to get your small house extension spot on.

Boot room within a utility space

(Image: © Lewis Alderson)

13. Convert an integral garage

If you have an integral garage, converting it to create a new living space may well be worthwhile. Always check, before you proceed, with a trusted local estate agent to ensure that you won't be damaging the value of your home or its saleability. But as a general rule, if on street parking is not an issue, or if you have off street parking, converting the garage will be valuable both in terms of living space and potential profit when you sell on. This garage, by Stephen Graver Architects, has allowed a small, dark kitchen to be opened out into a new living space, connected to the upper floor. Use our ultimate guide to find out everything you need to know about garage conversions.

Living space overlooking staircase and kitchen for garage conversion ideas: by Stephen Graver Architects

(Image: © Marc Wilson Photography)

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