Extensions & Conversions in Northamptonshire

Single and double storey extensions, conservatory conversions, garage conversions and loft conversions across Northamptonshire. Built by a family business with over 50 years of experience.

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Quality Extensions and Conversions Built to Last

For over 50 years, Boyson Construction has been transforming homes across Northamptonshire with carefully designed and skilfully built extensions and conversions. Whether you need extra living space, a brighter kitchen, or want to make better use of unused space in your home, we deliver projects that add real value to your property and the way you live in it.

Interior of home renovation in progress showing empty room with skylight, glass roof panels, cardboard boxes, ladder, and exposed walls

Every extension and conversion we take on is fully project managed in-house. From initial design conversations and planning permission support, through groundworks, structural work, and the final finishes, you have one team responsible for the entire job.

We're a family business with deep roots in Northampton and a reputation built on quality workmanship, reliability, and honest communication. Every project is delivered on time, on budget, and finished to a standard our clients are proud to show off.

Single Storey Extensions

The most popular type of extension we build, single storey extensions add space exactly where you need it most. Whether it's a larger kitchen, an extended living area, a new dining space, or a home office, we design and build single storey extensions that flow seamlessly with your existing home. Includes full groundworks, structural works, roofing, and interior finishes.

  • Full groundworks and foundations
  • Structural works and roofing
  • Interior finishes to match your home
Construction site showing large glass sliding doors and windows being installed on a brick residential building with a worker visible inside

Double Storey Extensions

For families needing more living space and additional bedrooms, a double storey extension transforms how a home functions. We build full double storey extensions including new bedrooms, en-suites, and expanded ground floor living areas. Every project is carefully planned to match the architectural style of your existing property.

  • Additional bedrooms and en-suites
  • Expanded ground floor living areas
  • Architectural matching to your property
Modern two-story residential house with cream and yellow brick exterior, black-framed windows, and a dark ground floor garage or extension.

Conservatory Conversions

Turn your old conservatory into a proper year-round living space. Many homeowners inherit a conservatory that's too hot in summer, too cold in winter, and barely used. We solve this by replacing the existing roof with a fully insulated, solid tiled roof, complete with insulation, plasterboard, and recessed LED lighting. The result is a space that maintains a comfortable temperature all year round and genuinely adds value to your home.

  • Solid tiled roof replacement
  • Full insulation and plastered interior
  • Year-round comfortable temperature
Modern brick house with multi-pane windows, extended patio area, and outdoor seating under cloudy sky

Garage Conversions

Turn an unused garage into a fully usable part of your home. Whether you want a home office, a guest bedroom, a playroom, or a self-contained annexe, we handle the full conversion, including insulation, structural changes, electrics, plumbing, flooring, and interior finishes. A garage conversion is one of the most cost-effective ways to add genuine living space.

  • Full insulation and structural changes
  • Electrics, plumbing and flooring
  • Complete interior finishes

Loft Conversions

Make the most of unused attic space with a professionally designed and built loft conversion. We handle dormer conversions, hip-to-gable conversions, and full loft conversions including new staircases, en-suites, and Velux windows, adding a full extra floor of usable living space without changing your home's footprint.

  • Dormer and hip-to-gable conversions
  • New staircases and en-suites
  • Velux windows and natural light

What Our Clients Say

Modern living room with herringbone wood flooring, large sliding glass doors overlooking a deck, a single wooden chair, and black kitchen cabinetry

Your Project, Done Properly

One team handling the entire project, from structural work through every trade to final finishes

50+ years of building experience, a family business with deep roots in Northamptonshire

In-house project management, one point of contact from first meeting to final handover

Honest, transparent quoting, clear schedules of work and no hidden costs

Extensions and Conversions Across Northamptonshire

We provide extensions and conversions across Northampton and the surrounding Northamptonshire towns and villages, including:

Northampton Wellingborough Kettering Daventry Towcester Rushden Brackley Market Harborough Corby Higham Ferrers Irthlingborough and surrounding areas

Take the First Steps to Plan Your Extension

Get a free no-obligation quote for your extension or conversion project today.