Thornwood Heritage Flush Casement
Heritage character. Refined proportions. Thoughtful detail.
The Thornwood Heritage Flush Casement is designed for projects where traditional character, slim sightlines and authentic proportions are essential. Its flush finish and carefully considered detailing create a sympathetic appearance for period properties, listed buildings and homes within conservation areas, where preserving the character of the building is a priority.
Available with slimline glazing options to help meet the requirements of heritage and planning specifications, the Thornwood combines traditional aesthetics with the benefits of modern timber window manufacturing. A considered solution for sensitive renovations and heritage-
inspired developments alike.
Key Specification
The Heritage Choice for Flush Casements
The Thornwood Flush range is built on the same robust frame system as our Sutton range, but designed specifically for conservation areas, listed buildings and heritage-sensitive projects where the fine sightlines of traditional single glazing need to be preserved.
Opening Styles
No Bar
Horizontal bar
Country Bar
Georgan Bar
Designed around your project
Explore our range of timber windows and doors, with options to suit different styles, specifications and project requirements. From glazing layouts and finishes to ironmongery and detailing, we’ll help you find the right solution for your project.
Any RAL colour, factory applied
From contemporary to traditional, choose the details that best suit your project.
Every Sashless window and door can be finished in any RAL colour. The shades below are the ones our customers choose most often, but they are a starting point, not a limit. If your project calls for a specific colour to match a scheme, satisfy a conservation officer or carry a developer’s house style, we can finish to it. Colours can also be split. You can specify the same colour inside and out, a different colour on each face, or a contrasting frame and sash, in any combination the design needs. All finishes are spray applied in our Northallerton factory using Remmers water-based microporous paints and stains. This gives an even, consistent coat that on-site painting can’t match.
Factory glazed, specified to suit the building
Every Sashless window and door is glazed in our factory using a dry glazing system to BS 6262, with a fully drained and ventilated bead design. Glazing in controlled conditions means a consistent seal and no site glazing to go wrong.
We offer 24mm and 28mm double glazed units, 28mm and 40mm triple glazed units, heritage slimline units for conservation work, and single glazing where a listed building requires it. Our slimline units are Krypton filled for thermal performance in a narrower profile. Glazing bars can be bonded with a duplex spacer for a true divided look, or fully structural where the specification calls for it.
Low emissivity, solar control, acoustic and obscure glass are all available. If a location needs safety glazing under Approved Document K, tell us at order stage and we will glaze to suit.
The Finishing Touches - Quality hardware, fitted before it leaves the factory
Hinges, locks and handles are fitted in our factory, set up and tested before delivery. Every window arrives ready to operate, with nothing to adjust or source on site.
We use established names including Maco and Titon, with a wide choice of handle styles and finishes to suit contemporary, traditional and heritage designs. Sash windows come with matching sash locks and finger lifts, and all fittings, including screws, are anti-corrosion treated.
Friction hinges with built-in restrictors are standard on our casement ranges. Specialist options cover fire escape hinges and handles, lockable restrictors, extended lever handles and folding cam openers for less able users, and manual or electric operating gear for high-level windows. Concealed trickle vents keep ventilation in line with Approved Document F without an unsightly canopy on the head.
Talk to us about finishes for your project and we’ll match the hardware to your design.
Cover that reflects how long our windows last
Every Sashless factory finished window and door comes with a 24-month standard warranty. When installed and maintained in line with our guidelines, this extends automatically to the cover shown below.
Shorter periods apply to translucent stains and heritage slimline glass units.
The maintenance itself is simple: regular cleaning, lubricating the hardware and checking the finish.
Built around your project’s requirements
Partnership
Straightforward, dependable and easy to do business with. We provide honest advice, clear communication and dependable service from first enquiry through to final delivery.
Craftsmanship
Four generations of British manufacturing expertise. Family-owned since 1965, we’ve built our reputation on craftsmanship, attention to detail and getting things right, project after project.
Performance
Every product is engineered for security, thermal efficiency and long-term durability, combining traditional craftsmanship with modern performance standards.
Sustainability
Responsibly sourced FSC®, solar power generated at our factory, and timber waste used to heat our manufacturing facility. Our windows and doors are built to last, with an expected lifespan of 60+ year.
Quality
Every product is manufactured, finished and quality checked in-house, giving us greater control over craftsmanship, consistency and performance.
Real projects, real results
From listed conversions to multi-plot developments, see how our timber windows and doors perform on real projects for developers, contractors and architects.
Frequently asked questions
What window ranges do you offer?
Two main systems: casement windows (our Sutton Traditional Flush Casement, Thornwood Heritage Flush Casement and Cleveland Modern lipped casement ranges) and vertical sliding sash windows (Richmond Contemporary Sash, Richmond Traditional Sash and Kingston Heritage Sash).
What's the difference between the Richmond and Kingston sash ranges?
Both are vertical sliding sash windows built to heritage proportions. Richmond is our standard sash range, available with weights and pulleys or a spiral balance mechanism. Kingston shares the same heritage look but offers slimline, Krypton-filled glazing, suited to especially sensitive conservation contexts where sightlines need to stay as close to original as possible.
What glazing options are available?
Windows are supplied factory-glazed with a choice of 24mm, 28mm or 40mm sealed units, using low-emissivity glass. Slimline units are also available on the Kingston range for heritage applications.
Ready to talk about your project?
Ask about Thornwood Flush windows for your project. Call 01609 780202 or email enquiries@sashless.com.