Spectra Extensions
Traditional Finish. Built Smarter
Looks like a traditional build. Delivered faster, better, smarter.
The Technology Behind Spectra Extensions
Advanced methods, traditional results. Our extensions are indistinguishable from conventional builds — and often more cost efficient too.
Screw Pile Foundations
Steel foundations installed in hours, not weeks. No concrete, no curing time, no excavation. Ready to build on immediately with less than 50% of the carbon footprint of traditional foundations.
Individually Engineered
Every Spectra Extension is uniquely designed by our structural engineers to maximise performance and quality. Superior U-values, 50+ year lifespan, and 50% less carbon than traditional builds.
Premium Brick Slip Finishes
Authentic brick finishes custom made to order, with a 98% match to your existing brickwork. 70% lighter than traditional brick, with lifetime durability.
A Smarter Way to Build Your Property Extension
Our transparent process takes you from initial enquiry to completed extension with no surprises.
Your Enquiry
Get in touch and one of our specialists visits your property to assess feasibility. In 95% of cases, a Spectra Extension can be built.
Engineering & Quote
Our structural engineer conducts a free technical assessment. You receive a fixed, confirmed price with complete transparency.
Detailed Planning
We create separate plans for each trade — electrics, plumbing, carpentry. You can change, add, or remove elements before signing.
Build & Handover
Fast foundations, quality construction, Building Control sign-off. Thorough snagging before final handover. Your satisfaction guaranteed.
Recent Projects
See the quality of our work. Every project is built to the same exacting standards.
Why Milton Keynes Homeowners Choose Our Spectra Extension Range
We combine modern construction technology with uncompromising quality standards. The result? Premium house extensions delivered faster, with less disruption.
Weeks, Not Months
Traditional extensions take 3-6 months. Our advanced process delivers in a fraction of the time.
Modern Methods, Premium Results
Every element is chosen for performance and longevity. From foundations to finishes, we use materials trusted by commercial developers across Europe.
Minimal Disruption
No concrete trucks blocking your drive. No excavators tearing up your garden. Our clean, efficient process respects your home and your time.
Cost Efficient
Smarter methods mean less waste and fewer delays. The efficiency of our process often translates to cost savings for you.
Quality You Can See and Feel
Every detail matters. From precision foundations to flawless finishes, we build extensions that stand the test of time.
Part of the Crownhill Building Services Family
Spectra Extensions is proudly operated by Crownhill Building Services, bringing years of construction expertise to every project. We combine our trusted local reputation with the latest building technologies.
Looking for a traditional extension or other building work? Visit cbsmk.co.uk for our full range of services.
Fully Insured
Premium Material Warranties
Planning Support Included
Local Milton Keynes Team
What Our Customers Say
Real reviews from our Google Business Profile
Your Dream Extension Awaits
Imagine more space, more light, more life. Let's make it happen.
Ready for Your House Extension in Milton Keynes?
Get a free, no-obligation quote from trusted extension builders. We'll visit your property, discuss your home extension requirements, and show you what's possible.