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Flush Sash Casement Windows in uPVC

Modern flush sash windows unite classic timber sightlines with the high performance and low maintenance features of present-day uPVC. Combined with advanced EcoMAX glass or Comfort Glass, flush sash windows are designed to heighten your home’s thermal performance and kerb appeal tenfold. Choose from a range of refined painted and woodgrain finishes or a diverse range of window colours, including on-trend shades like Anthracite Grey, Agate Grey, and Olive Grey.

Amongst the many custom design options available, for the ultimate finishing touch choose from a range of charming handle styles complete with secure locking including standard, traditional or contemporary. Learn more about your window & door journey with us via our simple design and buying process.

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White uPVC flush sash bay window

Sitting flush

The opening sash of the window fits flush with the outer frame for a seamless appearance

Hidden Corner Weld

An unseen corner joint helps create a seamless look. Choose from a fully welded, full mechanical or MechWeld joint

Identical sightlines

Enhance your home with same-width frames for equal sightlines

What is a flush sash window?

Intricately made to seamlessly replicate the look of authentic timber, flush sash windows fit sleekly into the window frame, instead of slightly overlapping the window frame for a smooth finish. Made from the highest quality uPVC, unrivalled energy performance, weatherproofing, and low maintenance finesse are a given. Well-known for the way they create traditional aesthetics without the traditional drawbacks, even the keenest eye won’t be able to tell the difference!

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Why choose a flush sash window?

Cost-effective, authentic timber sightlines

Much cheaper to construct than timber, our uPVC flush sashes can be customised in three realistic jointing options; fully welded, full mechanical, or mechanical/weld.

Advanced thermal insulation

Available with 3, 5 and 6 insulating chambers, our multi-chambered uPVC flush sash windows attain A energy ratings with ease.

Superior security

Complete with secure multi-point locking and able to last up to 35 years, our flush sashes are PAS 24 security accredited as standard.

Low maintenance

Our uPVC flush sash windows offer a maintenance-free design that won't rot, crack, warp, or fade throughout its lifespan (unlike real timber).

Sustainably sourced

As well as offering EcoMax Glass as standard, our flush sash windows are created from 80% recycled manufacturing off cuts.

  • Colours
  • Glazing
  • Frame Options
  • Furniture
  • Additional Features
  • Colours

    Our exquisite flush sash window colour palette comes in a whole range of beautiful colours including tranquil Cream, White Grain, and Natural Oak.

    White

    White

    Clotted Cream

    Clotted Cream

    Pearl Grey

    Pearl Grey

    Chartwell Green

    Chartwell Green

    Elephant Grey

    Elephant Grey

    Slate Grey

    Slate Grey

    Slate Grey Grained

    Slate Grey Grained

    Basalt Grey

    Basalt Grey

    Anthracite Grey

    Anthracite Grey

    Anthracite Grey Grained

    Anthracite Grey Grained

    Black Brown

    Black Brown

    Steel Blue

    Steel Blue

    Racing Green

    Racing Green

    Ruby Red

    Ruby Red

    Turner Oak

    Turner Oak

    Irish Oak

    Irish Oak

    Golden Oak

    Golden Oak

    Rosewood

    Rosewood

    Mahogany

    Mahogany

    Walnut

    Walnut

    Dark Oak

    Dark Oak

    Glazing

    Both ECOMax double glazing and Comfort Glass are available in the casement styles and we can also offer a range of textured and patterned glazing for added privacy or decoration. The benefits of upgrading your glazing are truly limitless - the most notable features include increased warmth, reduced energy bills & beating future energy price hikes. For complete peace of mind, we also offer toughened glazing options to enhance your home security further.

    The benefits of upgrading your glazing are truly limitless - the most notable features include increased warmth, reduced energy bills & beating future energy price hikes. For complete peace of mind, we also offer toughened glazing options to enhance your home security further.

    Frame Options

    Choose the perfect profile for your finished window

    We have a number of distinctive styles of frame to choose from. The chamfered option is a contemporary, straight-edged style while the ovolo option provides a more traditional, decorative finish. Our flush option sees sashes that finish flush with the external face of the window.

    Ovolo Frame

    Ovolo Frame

    Flush Sash Frame

    Flush Sash Frame

    Chamfered Frame

    Chamfered Frame

    Furniture

    Stylish furniture to make your windows even more complete

    We offer a range of furniture for your windows to look the part. Whether you want the traditional look with monkey tail handles in a vintage finish, or contemporary brushed steel, our elegantly designed handles bring form to functionality and are designed to fit naturally into the user’s hand. You can also choose from our selection of window restrictors and pegs.

    Furniture Handle Options

    Window Handle

    Window Handle

    Pear Drop Handle

    Pear Drop Handle

    Monkey Tail Handle

    Monkey Tail Handle

    Furniture Colour Options

    Black Finish

    Black Finish

    Brass Finish

    Brass Finish

    White Finish

    White Finish

    Chrome Finish

    Chrome Finish

    Steel Finish

    Steel Finish

    Additional Features

    Authentic Timber Look Cill

    For an even more authentic look, our Radlington Cill is a superior upgrade to our standard cills. Comprising of deeper nosed cills, one at the standard 30mm height and another at a 55mm height, these are modern interpretations of timber cills.
    Window with a white cill

    Overhead Ventilation

    Our overhead concealed ventilation features an overhead slot vent system that incorporates the ventilation in the head drip, meaning the external trickle vent is concealed on the head of the outer frame, providing a much-improved finish.
    Window with an overhead concealed vent

    Versatile flush sash window designs

    They say it’s often the little things that make the biggest difference. Each window is intricately made to meet your unique requirements, no matter how big or small your home improvement project is.

    We offer flush sash windows with fully welded, full mechanical, or mechanical/weld joints to create a style that will perfectly complement your home’s existing character. With a variety of authentic timber-replica finishes and classic extras like Georgian bars, decorative glass, or beautiful leaded detail to choose from, literally any look can be achieved.

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    Golden oak flush sash casement window
    Close up of flush sash window

    Can you put UPVC windows in a conservation area?

    Those living in listed buildings and conservation areas must take extra care that window and door replacements do not differ from the original design. So, first things first, be sure to check with your Local Authority whether your home is in a conservation area or not.

    Thanks to technological advancements, high quality timber alternative windows (like ours!) are designed to pass strict regulations in conservation areas. Robust, secure, and revitalising, you can count on our advanced flush sash windows to retain classic aesthetics whilst fully complying with the latest conservation rules in your area.

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    High performance flush sash windows

    Performing to some of the highest energy efficiency levels around, our flush windows are A rated as standard and can accommodate 28 mm ECOMax double glazing or 32 mm Comfort Glass with ease.

    Combined with modern multi-point shoot bolt security locks, stylish lockable handles and a convenient lockable night vent facility as standard, security issues associated with real timber - such as dry rot, pest infestation and warping - are a thing of the past with exquisite flush sash windows.

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    Black flush sash window
    anthracite grey flush sash window close up

    What is a window sash?

    A window sash is a frame that holds the glass panes within a window. It is the movable part of the window that can be opened and closed, usually consisting of vertical or horizontal panels that slide or pivot.

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    What is the difference between a casement window and a sash window?

    A casement window is hinged at the side and opens outward like a door, while a sash window has one or more movable panels that slide vertically or horizontally within the window frame. Casement windows provide unobstructed views and better ventilation, while sash windows offer a traditional aesthetic and are often found in older buildings.

    Double glazed window in traditional flush sash style

    Frequently Asked Questions

    Find all the answers to our most frequently asked questions below.

    How much will new flush sash windows cost?

    There are many aspects to consider when purchasing new windows, such as material, thermal performance and whether it's been accredited by industry bodies to ensure its quality. To accommodate the majority of budgets, we offer a range of comprehensive finance options, including 2 years interest free credit & buy now pay later. Find more information on double glazed window prices here.

    How do I know if my windows need replacing?

    Modern double glazing lasts at least 20 years, but there are certain tell-tale signs you need to look out for. Read more

    Which window material is best?

    The first decision you need to make is which window material is right for your home. Your final decision will be heavily influenced by your own personal choice, budget, property appearance and building era.   Read more

    What is A rated double glazing?

    Energy efficient home improvements are incredibly important, so if you're wondering how to tell what A rated glazing is you're not alone! Read more

    Begin Your Project

    Get your free quote – with no-obligation to buy. Simply fill in the online contact form below to get started:







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      Here at SEH BAC, we’re proud to have won many prestigious awards for our products as well as our work in the community:

      Installer awards 2022
      G21 Finalist
      SEHBAC showroom winner
      Ultraframe designer winner
      Conservatory and orangery awards winner 2019
      NHIC 2018 Consumer confidence award
      G17 Installer of the year
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