Sheerline Aluminium Windows & Doors

Transform your home with our high-performance aluminium windows and doors

The ultra slim 59mm sightlines* of the innovative Classic window system maximises the light flooding into your home, creating a refined architectural look. We’ve also designed out the misalignment of corners seen on lesser aluminium systems, using our patented construction method. Allowing each Classic window to be individually hand tuned to perfection. Leaving you with the perfect balance of understated refinement and exacting quality standards.

Choosing the right windows & doors for your home is an important decision

An investment that makes a real difference to how warm and secure you feel; as well as changing the look of your property.

This is why we have designed the Classic system from the ground up. Building on years of experience, we’ve incorporated many new innovative ideas, creating a warmer, slimmer and more secure system.

Designed for discerning homeowners who aren’t willing to compromise, our Classic range is tailored to those who demand more for their home. Built around an innovative Thermlock® multi-chamber thermal break, our windows use a patented construction method that offers unsurpassed levels of security.

Creating windows and doors that are strong and durable, yet with slim frames that maximise the light flooding into your home.

Thermlock® technology helps keep you and your home snug and warm

Clean, crisp lines on the outside hide away our innovative Thermlock® multi-chamber thermal design, helping keep you and your property well insulated against the worst of the UK weather.

Their insulating chambers act as a thermal break and work in conjunction with high-performance glazing to create class-leading thermal performance, far superior to traditional polyamide thermal breaks.

Sheerline’s cills also feature this same technology coupled with innovative in-built weather sealing that keeps draughts and rain safely outside.

With exceptional security built into the heart of every product

The innovative construction method of the Classic system creates exceptionally strong frames, maximising the inherent strength of Sheerline’s aluminium windows and doors.

This, coupled with our high security multipoint locking, helps keep you and your home safe and secure. Additional features like unique hinge protectors also help create outstanding levels of security.

For added peace of mind, choose our laminate glass upgrade – for Secured by Design accreditation – the official UK Police initiative ‘designing out crime’ through physical security. *

 †Patent registration number: GB2569209

For ultimate security, a beadless option is also available in the Classic window system, which eliminates the need for separate glazing beads. Instead, our patented† corner jointing method securely locks the glass away within a completely sealed unit. No window in its class is as secure.

Greenoak Concept & Design

Aluminium Window & Door Gallery

Are you looking for a quote for Aluminium Windows or Doors?

Why not get in touch with the Greenoak Concept & Design team today, and we will be able to provide you with a quote tailored to your project needs.

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Greenoak Concept & Design have been raising the standards for more than 14 years.

More about us: We’re an independent Essex-based specialists in high quality UPVC Windows, Doors, Tiled Conservatory Roofing, Wall Cladding, and Fascias, Soffits and Guttering.

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Thank You For Your Continued Support

Due to high demand, we are now accepting bookings for December 2026 installations, with our diary also open for 2027 projects.
As a special thank you to both our new and existing customers, we’re offering an exclusive: