34 Modern Extension Ideas to Inspire a Contemporary Addition to Your Home

modern extension ideas for a rural home
(Image credit: van Ellen + Sheryn)

There are modern extension ideas to suit every home if you look hard enough, no matter if you are building an extension to a new or period home. There is absolutely nothing to say that extensions have to match the building they are being added to. While matching materials for an extension can undoubtedly result in some seamless and very sympathetic additions, it can also produce some spectacularly bad results. 

The worst ‘matching’ extensions involve ugly visible seams where old and new meet, materials that almost, but don’t quite, look the same, rooflines that sit awkwardly together and windows with different frames to those used in the originals.

In many cases it is a far better idea to design the extension to sit in complete contrast to the original house in order that both sections can shine in equal measure. There is no reason why a contrasting extension has to be whacky or ‘out there’ either. Sometimes, just a selection of different materials or a shift in the shapes and forms used in the design are all that is needed. 

Our selection of modern extension ideas is here to offer you all the inspiration you need to ensure your new addition stands out for all the right reasons. 

1. Modern Farmhouse Extension

modern glass extension idea for a home

(Image credit: van Ellen + Sheryn)

This 'glass box' extension, designed by van Ellen + Sheryn Architects, has been added to a 19th century farmhouse. It utilises lightweight metal and a series of glazed sliding doors to give panoramic views of the beautiful rural surroundings. 

2. The Accessible Extension

single storey modern extension idea

(Image credit: Tigg + Coll Architects)

Designed by Tigg + Coll Architects, this striking extension project was created in order to transform a 1930s bungalow into a stylish accessible home.

The large extension has a self-supporting roof that features a timber diagrid design that forms a continuous canopy over the internal spaces and external terrace. The huge expanses of openable glazing link the new bedrooms within to outdoors.

Despite the huge difference in style between the extension and the original, now remodelled, bungalow, the lightness of form when it comes to the overall look of the addition means both sections of the new house can stand out architecturally.

3. A Futuristic Extension Design

Contemporary extension by Stan Bolt to existing home

(Image credit: Nigel Rigden)

Arts & Crafts meets futuristic fantasy with this modern addition and its wing-like roof from Stan Bolt Architect.

4. A Glass Box Extension

Glazed rear extension to Victorian house

(Image credit: Martin Gardner c/o AR Design Studio)

Frameless glazing sits alongside period brickwork in this stunning project designed by Hampshire-based practice AR Design Studio.

5. Maisonette Extension

small glass extension

(Image credit: Architect Your Home)

The owners of this east London maisonette wanted an open kitchen dining room, with views out over their garden. In order to achieve this in a rather limited space, a small extension has been created, designed by Architect Your Home, featuring an innovative roof structure that took inspiration from the ribs of a boat. The reverse pitch on the full height window was a design trick to maximise the views of the garden. 

6. A Modern Victorian House Extension

victorian house extension

(Image credit: Tigg + Coll Architects)

This extension to a Victorian family home was designed by Tigg + Coll Architects to follow the form of the existing house. The roof of the extension is pitched to reflect the pitch of the original house. The corner of the extension is cantilevered, allowing the entire glazed corner to be opened up. 

7. A Georgian House Extension

georgian house extension

(Image credit: van Ellen + Sheryn)

This Georgian cottage had been unsympathetically extended in the past. Rather than try to match the original house, a contemporary extension was designed by architectural practice van Ellen + Sheryn. The new addition is clad in Siberian larch, has a zinc roof and plenty of high performance glazing.   

8. The Side Return Extension Reinvented

modern side return extension

(Image credit: Matt Chisnall)

Not your average terraced house side return extension — this addition, conceived by Paul Archer Design, was created to infill a strip of unused land that lay between the existing house and an adjoining block of flats.

9. Curved Glass and Steel Extension

modern glass extension idea

(Image credit: van Ellen + Sheryn)

Set in a picturesque Dartmoor valley, this farmhouse has been fully refurbished and  extended with a contemporary curved-wall-to-roof structure wraps over a structural glass box which forms a new living room within. 

The extension, designed by van Ellen + Sheryn, allows for panoramic views across the valley.

10. Corten Steel Extension

corten steel extension

(Image credit: Snook Photography)

In order to open up the entire rear of this 1930s house in a Conservation Area, an exoskeletal corten steel frame has been used. 

Designed by Matthew Withers of Stylus Architects, the frames are made of 40mm-thick steel sections that hold four large panes of glass, two of which slide back to open up the newly formed kitchen and living space to the garden.

11. The Contemporary Yet Sensitive Extension

sympathetic modern extension idea

(Image credit: Matthew Smith)

Being located on the edge of a conservation area, Tim Offer Architects took great care with the design of this extension to a small agricultural barn.

The rear addition has almost doubled the footprint of the house and despite its crisp, modern appearance, repeats the gabled form of the original barn. 

12. Small Extension Idea

small modern extension idea

(Image credit: Studio Bark)

This striking little extension, by Studio Bark, might measure just four metres by three metres but it certainly has a big impact.

The ‘box’ features a timber frame that has been clad in offcuts of UK-sourced Western Red Cedar.The rainwater pipes have been concealed within the cladding void and now discharge into the raised planters on either side of the French doors. 

13. The Invisible Extension

modern glass extension

(Image credit: Ståle-Eriksen)

There is no reason why a contrasting extension should dominate or detract from the original architecture of a building — as this project, by Proctor & Shaw proves. 

The extension also features brick cladding which has been cleverly incorporated into the oversized linear lintel that frames the large expanse of sliding doors. 

14. Arts & Crafts House Extension

small modern extension

(Image credit: Edmund Sumner)

The inspiration for this brick and timber ground floor extension by Proctor & Shaw was taken from the timber staircase, bay windows and fireplaces elsewhere in the house. 

This extension is dominated by a striking 3m wide ‘bay’ window that combines oak beams and an accoya bi-fold window. 

15. A 1930s Home Extended

This 1930s semi detached house has been transformed by its owners into a bright and happy family home — all for just £40,000

(Image credit: Clive Doyle)

A modest rear extension to this 1930s semi-detached home offers the extra space the growing family needed, while keeping within a tight budget.

16. A Cantilevered Addition

A pairing of a dramatic cantilevered extension and stone barn brings a vibrant feel to Paul and Elaine Haffey’s new home

(Image credit: Chris Hill)

A dynamic new cantilevered extension connects with this original stone barn, forming an angular and quirky stepped layout inside and providing a spectacular master bedroom space.

17. A Flat Roof Extension

Two extensions have transformed Sue and Terry Austin’s Hampshire house into a comfortable modern home

(Image credit: c/o AR Design Studio, Martin Gardner)

A flat roof rear extension designed by AR Design Studio houses a large kitchen diner and opens up the ground floor of this Hampshire home. A second two-storey side extension, clad in the same London stock brick as the existing property, houses a utility at ground level and a new master suite above.

18. A Series of Contemporary Bolt-Ons

Farmhouse With Contemporary Extensions

(Image credit: David Barbour)

A collection of contemporary extensions designed by Paper Igloo, clad in timber and Cor-ten steel and connected by glazed links, has been added to an old farmhouse.

19. A Bungalow Transformed

A 1970s bungalow has been transformed in to a modern, open plan home with a contemporary remodel and extension

(Image credit: Jeremy Phillips)

A far cry from the existing dated red-brick bungalow, the homeowners here added a single-storey extension and internal and external remodel to create a California-style home.

20. A Wrap-Around Extension

two-storey extension with glass façade wraps around this listed water tower

(Image credit: Jeremy Phillips)

Thanks to the vision of Ellis Williams Architects, a convex two-storey extension with glass façade wraps around this listed water tower.

21. A Box-Out Addition

timber frame extension to bungalow

(Image credit: Simon Maxwell)

From bungalow to brilliant — this timber frame first floor addition with contrasting cladding boasts wow-factor.

22. A Timber Triumph

Extension to Historic Home

(Image credit: Alistair Nicholls)

Designed by Beam Cottage Architect, a new glazed link offers a transition between this period cottage and its modern rear, complete with a dramatic timber first floor box.

23. From Chalet Bungalow to Chalet Style

Remodel and extension of bungalow

(Image credit: Paul Arthur)

A dramatic first floor extension, complete with covered balcony has turned this bungalow into a chalet-style home that wouldn’t look out of place in a luxury ski resort.

24. A Basement Extension

Extension for Victorian Basement

(Image credit: Simon Maxwell)

A stylish basement extension designed by Riach Architects offers open plan family space to a Victorian terrace in Oxford.

25. A Steel-Clad Extension

A striking Cor-ten steel-clad extension to a granite steading in Aberdeenshire offers open plan living to its owners

(Image credit: David Barbour)

This double-height Cor-ten steel-clad wedge by Andrew McAvoy of Retool Architecture offers striking contrast to a granite steading.

26. A New Bedroom Extension

Single-storey extension to house

(Image credit: Simon Maxwell)

A post-war property has been expanded thanks to a unique timber-clad corridor of bedrooms designed by Dan Brill Architects.

27. A Two-Storey Addition

A dated bungalow has been transformed with a modernist-inspired renovation and extension

(Image credit: Darren Chung)

A boring bungalow becomes a Modernist masterpiece thanks to a two storey additio by Matt Maisuria Architects.

28. A Farmhouse Extended

Wayne and Lorrie Bilsborrow have transformed their granite farmhouse with the addition of a contemporary timber extension

(Image credit: Nigel Rigden)

A larch and stainless steel wing by Room Architects offers a dynamic contrast to this period farmhouse — and proof of just how these older agricultural buildings can be transformed.

29. A Glass Basement Addition

A listed London home has been extended in glass, creating a contemporary living area above a new basement studio

(Image credit: Simon Maxwell)

This glazed box designed by Belsize Architects proves that extensions do not have to be huge to make a visual impact.

30. A Glazed Side Extension

Light-filled Extension to a Victorian Home

(Image credit: Simon Maxwell)

Shards of glass lend to the futuristic feel of this flat-roof addition to a Victorian home, designed by Coffey Architects.

31. A Timber Box Extension

A 1970s home on a Hampshire cul-de-sac has been transformed into a modern, eco-friendly timber clad home.

(Image credit: Nigel Rigden)

A new timber frame box linked via glazed panels from PAD Studio renders this 1970s home unrecognisable.

32. A Multi-Storey Tower

A stunning and unique contemporary extension to a listed Victorian home in East London

(Image credit: Nigel Rigden)

Adding interest, this multistorey timber tower rear designed by 51% Studios sits above a new light-filled base, offering increased accommodation.

33. A Stepped Extension

Alex and Sophie Nicholls have enlarged their traditional 1950s house with two contemporary box-shaped extensions designed to bring in the light

(Image credit: c/o AR Design Studio)

A series of jagged boxes set off from one another – one grey rendered, one timber clad – offers a splash of modern style, designed by AR Design Studio.

A modern glass addition to their cottage has enabled Adrian and Amy Mole to convert and incorporate outbuildings to create one characterful, unique home

(Image credit: Alistair Nicholls)

This functional, frameless glazed link by Emrys Architects connects three buildings to form one home.

Daisy Jeffery

Daisy was Features Editor on Homebuilding & Renovating magazine for more than five years and had a passion for all things design. She has since moved on to pastures new.