When it comes to extending your home, there is no one-size-fits-all solution. While the list of must-haves and wish list features will undoubtedly vary from project, the one thing all extensions have in common is the need for the project to reach completion on time and budget.

If you are thinking about adding extra space to your existing home with an extension, take a look at the incredible projects below, organised by build cost, for an idea of the kind of thing you can achieve on your budget.

Under £50,000

An ICF Addition

ICF extension to a traditional cottage

Built using the BecoWallform 313 system, which provides U values of just 0.18kW/m², using an ICF construction system also offers a quick build time, and can be used with almost any cladding material

This cottage in the Scottish Borders has undergone a significant refurbishment, complete with a large extension constructed using insulated concrete formwork (ICF) from BecoWallform.

Render was chosen to contrast against the existing stone cottage, while matching roof tiles help to tie the two structures together so the building reads as one. The cost for the Wallform structure here came in at just £12,144 (although this doesn’t include the rest of the extension costs).

Adding Extra Living Space with an Orangery

Orangery extension with roof lantern

An orangery from Anglian Home Improvements costs from £18,000 for design, materials and installation

Anglian Home Improvements was commissioned by the owners of this home in Bedford to add an orangery to create an indoor/outdoor space on a budget.

The new addition allows the interiors to be opened up through aluminium bifold doors to give a panoramic view of the landscape. A roof lantern also allows natural light to flow into the home.

A Budget Extension to Semi-Detached Home

Budget extension to a post war house

Homeowners Samantha Worrall and Philip Osborne wanted to create more space within their 1930s semi-detached family home on a limited budget. They chose a contemporary rendered extension to the rear of the property, along with a small side extension that runs down one side of the house.

The flat-roofed extension is now home to a bright open plan kitchen, dining and seating space, while the side extension has provided a bright entrance hall and WC, which the existing property had lacked.

The project was completed for just £40,000.

Oak Frame Kitchen Extension

It was important that the design of this extension was sympathetic to the original property and its surroundings as it sits within an Area of Natural Beauty in the Welsh countryside

These homeowners approached Welsh Oak Frame with a brief for an open plan kitchen/dining/living space the whole family could enjoy, with a home office on a mezzanine level overlooking the kitchen, as well as a bedroom with en suite and a separate living room.

They chose an oak frame route as they felt that exposed oak would be in keeping with the style of the original Welsh farmhouse and would add character and warmth to the new space.

The glazed wall allows natural light to flood the space and provides great views of the local landscape

Oak bifold doors with a large window above combine to create a fully glazed wall at the end of the room, revealing impressive countryside views and allowing natural light to flood the interiors.

The extension cost £40,000.

Oak and Glass Single Room Addition

The approximate cost for the supply and erection of the oak frame was around £45,000

The homeowners of this project approached Border Oak to design and build an oak and glass single room extension to their listed Arts and Crafts house, joined with a modern frameless glass connection so that the two parts can be easily distinguished.

The oak frame extension sits on a brick plinth and boasts a double-height vaulted ceiling complete with exposed beams and trusses. It also features glazed insert panels which bring in plenty of natural light. 


Under £100,000

Kitchen Extension to Grade II-Listed Cottage

This beautiful kitchen extension complements the existing 18th-century Grade II-listed house thanks to its use of matching stone roof tiles

As part of a whole-house remodel, designed by architectural designer Charlie Luxton, the kitchen extension fulfils the client’s brief for a light-filled space which connects to the outside through full-height sliding glass doors.

High-level windows to one elevation provide privacy, but bring in even more light — as does the glazed gable. While the overall project came in at around £259,000, the kitchen extension itself cost £82,500.

Extra Space Added for the Perfect Kitchen

Border Oak designed this single-storey kitchen extension to the rear of a listed house

For this extension, a small link structure was formed to connect the two parts of the property; the new section is completely self-supporting and independent. The new addition has been weatherboarded to fit in with the vernacular and gives the impression of a barn that may have been an outbuilding to the host house.

A wall of glass connects the interiors to the garden, while the vaulted ceiling creates a great feeling of volume in the space. The build cost for a similar extension would be £75k-£85k depending on specification.

Oak Orangery for a Period Property

The owners of this period property in Cheshire wanted to create an additional space leading off from the kitchen to accommodate a seating area with dining table

The designers at Arboreta came up with an orangery constructed of oak frame on a brick plinth. The new extension is a light-touch addition to the front elevation, thanks to the glass panels and large roof lantern — which also helps the space to feel light and airy internally.

French doors opening onto the terrace with oak-framed windows on all sides have transformed how the house works and created an indoor/outdoor feel to the open plan kitchen/dining/living space, making it perfect for entertaining.

Arboreta carries out projects of this type for around £60,000.


Under £200,000

Contemporary Glazed Addition

A love of everything glass prompted the owners of this Winchester property to ask Andy Ramus of AR Design Studio to design a contemporary extension, complete with a striking glass staircase with rooflight above.

Located at the rear of the house, the extension is constructed with frameless glazing, giving a clean, delicate appearance to this open, light-filled kitchen/dining/living area, while still showing the property’s traditional brick-clad exterior.

This extension cost £120,000 for materials and construction.

Wow-Factor Extension to a Victorian Semi

Creating a wow factor rear extension with extra space for an open plan kitchen diner was Paul Wiggins Architects’ brief for this Victorian semi-detached home in the conservation area of Kew, London 

As part of this rear extension project, the owner was keen to introduce more light into their new space; choosing a pyramidal glazed roof and large full height sliding glass doors which link to the garden over a level threshold — the angular design of the new addition also leads the eye outside.

The extension, which was part of a whole ground floor remodel, cost around £180,000.

Terraced Home Extension to Bring the Outside In

Clad in crisp white render, the extension has full-height sliding glass doors which lead out onto a terrace; this has been built to be flush with the kitchen floor to help achieve an integrated indoor/outdoor feel

The owners of this terraced home in East Dulwich enlisted architectural firm Selencky///Parsons to improve the kitchen and dining space, the connection between the front and back of the house, and maximise potential to capture panoramic views across London from the ground floor.

By extending into the side return of the property and reimagining the circulation space, a sequence of zoned spaces within an open plan layout have been created, while clerestory windows and a rooflight help to bring natural light deep into the home.

The project cost £140,000.


Under £400,000

Striking Addition to North-east London Home

Clear Architects’ founder Melanie Clear has designed a new ground floor garden room and two gabled first floor extensions for the owners of this north-east London property

Clad in a combination of render and charred timber, the ground floor extension is wrapped in glass. Deep cantilevered eaves offer protection from the elements when the large sliding aluminium framed doors are open. Two frameless rooflights within this space also create stunning views of the sky as well as allowing light to pour into the extension.

Upstairs in the new gabled first floor extension, a balcony is accessed through sliding doors from the bedrooms. The balconies overlook the sedum roof and roof windows of the ground floor extension.

This project cost £360,000 for construction and materials.


Under £500,000

Tripling Space with a Radical Design

Built in brick and block, the home now boasts kerb appeal thanks to its timber cladding and render finish, modern roof tiles and new aluminium glazing. A Juliet balcony also fronts the property

With a view to radically overhauling a dated 1930s red-brick dormer bungalow in Sutton Coldfield, the homeowners called on S&S Architecture to carry out an impressive transformation of their home, extending the property on all four sides.

The series of extensions to the front, sides and rear means the home has nearly tripled in size, from 186m² to over 510m². The former three-bed home now has five generous bedrooms, all with en suite facilities.

The work cost just under £500,000.


Over £500,000

Large Side and Rear Extension in Hampshire

The homeowners behind this Hampshire property commissioned AR Design Studio to design an impressive 250m² extension to the side and rear of their home

Part of the brief for this impressive extension was to clad the entire structure in a fresh palette of materials, including grey cement board, zinc and timber, to tie the extension in with the existing building which had previously been clad in brick and render.

The new extension has been designed to act as a self-contained guest wing for the couple’s children and grandchildren when they come to visit, and features its own kitchen diner, lounge, four bedrooms and underground parking.

The size of the new wing, coupled with the fine attention to detail and high-spec finish meant that this project was completed to a high budget.

High-spec Brick Extension to Victorian Semi

This extension was designed to focus on using high-quality materials and construction detailing, rather than using elaborate architectural features

Lewandowski Architects was commissioned by the owners of this Victorian semi-detached property in Windsor to transform and extend a series of compartmentalised rooms towards the rear of the house into one large open plan space. 

The new extension has been clad in stock brick to blend seamlessly with the existing Victorian property. Large-format, steel-framed windows and doors sharply enhance the exterior and provide a nod to the architectural period of the original house. The expansive doors open the space up onto a new south-facing patio and garden.

Bespoke joinery, high-quality finishes, lighting and a central kitchen by Bulthaup provide the centre pieces to the project, and a new AV (audio visual) system allows the client to monitor and control the house from anywhere in the world.

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