You Won't Believe These Extension Projects Were Built for Under £50k

Oak frame extension with glazed link
(Image credit: Border Oak)

Careful attention to detail, sourcing local materials, carrying out any work you can on a DIY basis and keeping one eye on the costs can all help to bring your extension project in on a tight budget.

If you are in need of some extension inspiration, take a look at this selection of projects that have all been achieved within a £50,000 budget.

(MORE: Building an extension)

A Glass Box Extension to a Listed Cottage

glass box extension to a listed cottage

(Image credit: IQ Glass)

Designed by Eastabrook Architects, the structural glazing of this extension injects natural light into the open-plan kitchen and adds an elegant, modern touch to the classic Cotswolds cottage. 

(MORE: Glass Box Extension Ideas)

  • Cost: £34,000 (structural glazing only, supplied by IQ Glass)

A Rear Extension Transforms a Semi-Detached Home

rear extension to semi-detached house

(Image credit: Sentinel Design & Build)

Replacing an existing conservatory, this stylish new rear extension opens up gracefully towards the garden with bifold doors, while the vaulted ceiling with two new rooflights in the extension creates a bright and airy atmosphere. 

  • Cost: £39,000 (current estimates for a similar project by Sentinel Design & Build would be approx. £49,000)

A Bright Zinc-Clad Extension to a Victorian Villa

pink rear extension

(Image credit: David Barbour)

This dated Victorian villa in Glasgow was renovated and extended into a dingy outhouse to create a new kitchen and lounge for a young family. 

The 1.85m wide infill extension works in harmony with the existing villa while the new zinc full-height dormer window brings much-needed light into the new space. 

(MORE: How to Build a Budget Extension)

  • Cost: £24,000

A Cost-effective Side Return Extension

side return extension

(Image credit: Adam Saran c/o Build Team)

Wanting to add a new bathroom and an open-plan kitchen, the owners of this London terrace ground floor flat chose Build Team to design and build a 7m² side return extension

  • Cost: £50,000

Modern Extension to Semi-detached Family Home

rear extension to home

(Image credit: Adam Scott)

Architect Lewis Bailie and his wife Preeya added a 20m² single-storey extension to their family home in Kent but kept costs to a minimum by managing contractor contracts themselves. 

The masonry construction features a pitched Siberian Larch roof – which ensures the room feels specious and practical – and a glass link to join the old and new sections of the house. 

(MORE: Extensions for Every Budget)

  • Cost: £40,000

A Characterful Rear Extension

characterful extension

(Image credit: Resi)

With a brief for a larger kitchen and dining area that was practical for everyday use as well as social occasions, Resi designed a rear kitchen extension that retained the country charm of the existing house, while expanding the living areas. 

The simple square construction fell under Permitted Development rights to reduce overall costs. 

  • Cost: Similar build projects would be estimated at £50,000

A Side Extension to Create a Dream Kitchen

side extension with kitchen

(Image credit: Kasia Fiszer)

Unhappy with their dark and dingy kitchen, Rachael and Adam Ball renovated and extended to the side of their terrace house to create an open-plan kitchen and living space. 

The couple took on much of the work on a DIY basis including designing and painting the kitchen, fitting the flooring, radiators and skirting boards. 

  • Cost: £45,000

A Sympathetic Oak-Frame Extension

Oak frame extension to a stone house

(Image credit: Welsh Oak Frame)

Looking to add a new kitchen diner to their farmhouse in north Wales, the homeowners of this project chose Welsh Oak Frame to design and build their new addition. 

The oak frame extension complements the original farmhouse and adds character and warmth to the new space.

  • Location: North Wales
  • Cost: £40,000

An ICF Addition to a Cottage

ICF extension to a stone cottage

(Image credit: Beco Wallform)

This cottage on the Scottish Borders has been subject to a large extension constructed using ICF (insulating concrete formwork) from Beco Wallform.

  • Location: Scottish Borders
  • Cost: Approximately £12,000 (for the Wallform structure)

Oak frame extension with glazed link

(Image credit: Border Oak)

Completed by Border Oak, this oak and glass single room extension has been added to a listed Arts and Crafts house, and joined with a modern frameless glass connection so that the two parts can be easily distinguished.

(MORE: 20 House Extension Ideas for Essential Extra Space)

  • Cost: £45,000 (for the supply and erection of the oak frame)

A Modern Orangery Extension to a Period Home

Glazed sunroom extension

(Image credit: Anglian Home Improvements)

The owners of this period home wanted to introduce more space, and commissioned Anglian Home Improvements to add an orangery extension.

  • Cost: £18,000 (for design, materials and installation)

A Kitchen Diner Extension Full of Natl Light

Kitchen-diner extension with country-style kitchen

(Image credit: Chris Snook)

With a view to creating a more traditional space in keeping with the existing building, the clients behind this project were keen to knock down the old side extension to make way for a new addition.

The extension, designed by Design Squared, is clad in white render, and houses an open plan kitchen/dining/living area that is connected to the rear reception room.

A 1930s Semi Extension on a Budget

Modern single storey extension to semi-detached home

(Image credit: Clive Doyle)

The challenge for Samantha Worrall, an architect by profession, and Philip Osborne was how they could create more space for their growing family within their 1930s semi-detached home on a limited budget.

The answer to the problem came in the form of a crisp and contemporary rendered extension to the rear of the property, along with a small side extension that runs down one side of the house.

(MORE: Modern Extension Design Ideas)

  • Cost: £40,000

A Bright and Charming Glazed Lean-To Extension

Conservatory extension to stone-clad property

(Image credit: David Salisbury)

The owners of this stone-clad home in Frome, Somerset were looking to create additional space off their existing kitchen. The couple opted for a lean-to conservatory filled with natural light.

Enlisting the services of David Salisbury, the design team at the company created a simple but effective design to perfectly fit the bill, complete with two skylights and top-hung windows for ventilation.

(MORE: Kitchen Conservatory Extensions)

  • Cost: £40,000

A Rear Addition for Extras Space

Contemporary extension to a 1970s semi-detached home

(Image credit: Eclipse Property Solutions)

After previously carrying out a garage conversion to this 1970s semi-detached home, Eclipse Property Solutions was enlisted once again by the homeowners to build a new kitchen/dining/family space to the rear.

  • Cost: £49,000

An Oak Frame Kitchen Extension

A single storey extension with vaulted ceiling

(Image credit: Croft Architecture)

With a growing family, the owners of this three bedroom detached house in Staffordshire were becoming increasingly constrained by the property’s size.

Reluctant to move out of the area, the homeowners appointed Croft Architecture to come up with a design concept that would see their old, cold, leaking conservatory replaced with a modern, light-filled, open plan extension.

(MORE: Rear Extension Ideas)

  • Cost: £50,000

A Modern Kitchen Extension to a Semi-Detached Home

Contemporary kitchen-diner extension

(Image credit: Eclipse Property Solutions)

When the homeowners bought this semi-detached home in London, they knew immediately they wanted to create a new extension to the rear of the property.

A new 8m x 5m flat roof extension was built and clad in London Stock bricks to match the existing brickwork, with reclaimed bricks, also London Stock, used internally as a feature wall. A bank of rooflights brings natural daylight into the new space.

  • Cost: £45,000

Calculating Your Extension Costs

Looking to work out the build costs of your extension? Find out how much yours could cost with our extension cost calculator.

Amy Reeves

Assistant Editor Amy began working for Homebuilding & Renovating in 2018. She has an interest in sustainable building methods and always has her eye on the latest design ideas. Amy has interviewed countless self builders, renovators and extenders about their experiences for Homebuilding & Renovating magazine. She is currently renovating a mid-century home, together with her partner, on a DIY basis, and has recently fitted her own kitchen.