About Spectra Extensions
Trusted extension builders since 2006
Part of the Crownhill Building Services Family
Spectra Extensions is the dedicated extension arm of Crownhill Building Services, combining 20 years of experience as building contractors with the latest construction technologies.
Founded in 2006, we've built our reputation as trusted local builders known for reliability, quality craftsmanship, and complete customer satisfaction. Our team has remained consistent throughout our history, bringing unmatched experience to every project.
We specialise in single storey house extensions throughout Milton Keynes and surrounding areas, including rear, side, and kitchen extensions. Our advanced methods deliver extensions that look and feel exactly like traditional builds — matching your existing property seamlessly — but completed in weeks, not months.
Why Choose Us
What sets us apart from other home extension builders
On Time, Every Time
We turn up when we say we will and finish when we promise. Your time matters to us.
Zero Insurance Claims
In 20 years, we've never had an insurance claim. Quality work means peace of mind.
Respect Your Home
We work tidily, clean up daily, and treat your property as if it were our own.
Proven Track Record
Over 500 completed projects and counting. We're happy to show you our previous work.
What Our Clients Say
Real feedback from homeowners across Milton Keynes
— Mark W., Stony StratfordExcellent company. They did exactly what they said they would, when they said they would. The whole team are friendly, hard-working and take real pride in their work.
— James T., Newport PagnellWe couldn't be happier with the quality of work. Eric and his team kept us informed at every stage and the finished result exceeded our expectations.
— David & Karen R., BletchleyFrom the initial consultation through to handover, everything was handled brilliantly. The fixed price quote meant no surprises. Highly recommend.
Ready to Start Your House Extension?
Get in touch for a free, no-obligation quote and see why hundreds of homeowners trust our experienced builders with their home extensions.