Premium, Bespoke Box Sash Windows

With extensive experience in designing & manufacturing premium quality sash windows – you can expect nothing but the finest, durable, high-quality windows delivered directly to your door.

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Discover our wide range Box Sash Windows and doors and get a free, no-obligation quote!

Box Sash Windows

Our joinery makes box sash windows using fine timbers in a variety of colours and stains and to bespoke sizes.

Box sash windows are sometimes also called “Hung Sash” windows or “Sash and Case” windows. All of these names essentially refer to the same thing, i.e. a window with one or more sliding panels or “sashes” which each hold a pane of glass.

Typically each frame contains two sashes which both slide vertically so that you can have an opening at the top or bottom of the frame or both if desired. This is actually one of the most effective ways of ventilating a room since the top opening allows warm air to escape, and the bottom opening allows cooler air to be drawn in from outside, creating an efficient airflow current.

We design your Box Sash Windows to fit your exact size & style specifications, we manufacture and supply to the whole of the UK with fast delivery & a product guaranteed to last.  The process is simple, simply contact us with your requirements, we’ll quote you, if you proceed you’ll be guided through our established process of design, approval, manufacture & delivery (with optional install services available).

Timber box sash & oak box sash window prices vary.

Box Sash Windows Security Testing is Complete with Wrap Round Locking (PAS24 Security). 10 Year Product Guarantee (Installed), 5 Years for Trade. We use our own designed door system (not generic off the shelf systems), we use kiln-dried sapele for stability & product durability.

Strength, Durability & Premium Quality

As an established business, Windows Doors UK (part of the Country Hardwood group) set out to produce premium quality products that combine modern eco-friendly, robust design with exceptional durability + timeless, classic design. We believe every Box Sash Window should excel in quality, aesthetic design & lifetime durability.

Our long-term establishment + 50+ years of combined experience amongst our team are reflected in the sheer quality of our products. Every box sash window, every sash window, french door & casement window leaves the factory after stringent quality control checks and rigorous testing.

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We strive to use the best quality materials sourced with ecology in mind. We use wood sourced from sustainable resources & responsible practices to ensure our ecological footprint is reduced where possible.

From wood supplies to window gaskets – everything we do we aim to reduce our carbon footprint.

The precision manufacturing that goes into our Box Sash Windows means that our windows are very energy efficient, further reducing heat loss, wasted energy, and overall carbon emissions.

Some of the most popular types of wood used include Accoya, ash (American white), ayan, beech, black walnut, cherry, iroko, maple, meranti, oak, sapele, steamed beech and teak.

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Box Sash Product Benefits

  • Excellent Thermal Efficiency with ultra-low U-Values (subject to Glass & Unit Type)
  • Exceptional Product Durability – Our box sash windows are made to last with a minimum 5-year guarantee
  • Low Maintenance – long intervals between treatment/paint applications
  • Heavily Customisable – bespoke sizes up to 3m, custom window bars & ironmongery
  • Multiple Glazing Options with Single, Double and Triple Glazing Options on Box Sash Window Units
  • Excellent Acoustic Performance
  • Twin Gasket System for Weatherproofing

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Box Sash Windows Gallery

Wide Range Of Window Design Textures

Box Sash Windows are incredibly quick and easy to replace (in comparison to other types of windows). But Box Sash Windows are more than just an easy solution to replacing tired, old, condensation strewn windows.

Oak Stains




Mid Oak

Mid Oak



Idigbo Stains



Mid Oak

Mid Oak




Sapele Stains



Mid Oak




Mid Oak

Opaque Colours

















Powder Blue




Sea Green













Box Sash Window Prices & Sizes

Please call us to discuss sizes and prices. We supply all standard and non-standard sizes, prices are available by quote. Please find a rough cost per size table below. * Based on a single window

Width (mm)
Height (mm) 400-500 501-600 601-700 701-800 801-900 901-1000 1001-1100 1101-1200 1200+
800-900 £350 £360 £370 £380 £390 £400 £425 £475 Call Us
900-1000 £360 £370 £380 £390 £400 £425 £450 £500 Call Us
1001-1100 £370 £380 £390 £400 £425 £450 £465 £520 Call Us
1101-1200 £380 £390 £400 £425 £450 £465 £495 £550 Call Us
1201-1300 £390 £400 £425 £450 £465 £490 £515 £565 Call Us
1301-1400 £400 £425 £450 £465 £490 £515 £525 £575 Call Us
1401-1500 £425 £450 £465 £490 £515 £525 £555 £605 Call Us
1501-1600 £450 £500 £510 £515 £525 £555 £585 £635 Call Us
1601-1700 £500 £510 £520 £525 £555 £585 £600 £650 Call Us
1701-1800 £510 £520 £545 £555 £585 £600 £625 £675 Call Us
1801-1900 £520 £545 £555 £585 £600 £625 £650 £700 Call Us
1901-2000 £545 £555 £585 £600 £625 £650 £675 £725 Call Us
2000+ £555 £585 £600 £625 £650 £675 £700 £750 Call Us

Window Prices


Our Box Sash windows are manufactured to high standards with specifications to match, generic specifications are below (specification relative to design).

  • Standard and made to measure sizes
  • Single, double and triple glazing
  • Bar design options
  • Engineered using laminated timbers which increase product durability, lifespan and reduces maintenance
  • Espag locking window gear
  • Height up to 3 meters
  • Finished products in white or other colours
  • Traditional or contemporary ironmongery features
  • Full instructions for self-assembly and installation
  • Twin gasket system for weatherproofing
  • Increased ventilation with lockable mechanisms on open windows
  • Flush window systems available
  • Fully tested and approved gaskets and seals
  • Glass is toughened
  • Good thermal performance (minimal heat loss)
  • Good security performance (thanks to effective locking mechanisms)
  • Good weather performance (durability against weathering, heat loss, UV damage)
  • Good acoustic performance


Download Gaskets Specification Brochure
Download Locking Systems Specification Brochure
Download Saint Gobain Glass Brochure
Download Pilkington Glass Brochure
Download Ironmongery Options Brochure

Trade Box Sash Windows

We supply this product to traders and:

  • Architects
  • Property Developers
  • Property Renovators
  • Installers
  • Commercial Businesses
  • Tradesmen

If you have a trade enquiry or would like to order this product in bulk then please call us on 0333 335 5416 to discuss or fill out the call back form to the right.

Lead Time

Our lead times vary depending on product specification and volume. We aim to have the shortest possible lead time from order to delivery, call us for a free quotation/estimate.

Box Sash Window CAD Drawings

There are no CAD Drawings available for Download, please contact to request drawings.

The “Box” or “Case” which is sometimes referred to is the casing at the sides (and sometimes top) of a sliding sash window frame. These would traditionally house lead weights, attached to the opening sashes by cords or chains via pulleys in order to balance the weight of the sash and allow it to be left in any position when opened. With modern frames, other methods of balancing the sashes are often used, such as the spring balances which we use in our sash windows. These modern balances are constructed from two counter-spiralling springs within a tube, arranged in such a way that the overall force exerted by the springs to pull the sash upwards is near-constant for the full range of extension of the spring. This means that the springs effectively “balance” the weight of the opening sash for its full range of movement, as if a counterweight were used, unlike a simple coil spring which would “pull harder” the more it is extended, making it unsuitable for use in sash windows. The size of casing needed to house the lead weights fitted to traditional box sash windows meant that the windows would usually be fitted into a reveal, i.e. with part of the frameset behind the brickwork of the building. This means that the window would effectively have to intrude into the inside space of a room. Spring balances take up much less space than lead balance weights, and as a result, we can now make windows with much narrower frame components, designed to be fitted into a standard brickwork cavity in much the same way as hinged casement windows. These thinner frames mean that you can maximise the glass area within a given opening size, letting as much light in as possible. Spring balances and their frames are also generally more cost-effective than lead weights and the large timber frames needed to house them, making them very competitive on price – even competitive with softwood and uPVC windows in many cases. Please contact us for a quotation today! If you are interested in our window products or would like a free quotation, please fill out our callback request form, or call us on 0333 335 5416.
Windows & Doors UK have experienced designers who can help you with the design and style aspects of your box sash windows. From frame style to woodwork, from ironmongery options through to installation our designers can assist. CAD drawings are produced outlining the windows dimensions, design and functionality aspects.
Decorative ironmongery for windows can play an important part in the overall look of new timber windows and doors. We source and provide a range of ironmongery options for windows and doors that complement the overall look and feel of the product. From traditional to victorian, from modern to contemporary styles, you choose the handle style that fits your preference and we’ll ensure your windows and doors come supplied. Download Ironmongery Options PDF
If you are looking to replicate an existing window style for your new hardwood windows then please give us a call on 0333 335 5416 to discuss your replica window requirements. Some historic windows can (depending on age) be hard to find parts for, or may well be beyond economical repair, at which point, replica windows are ideal to replace with ‘a like for like’ style with new materials and parts.
Windows & Doors UK make ordering a straightforward process. Once you have chosen your window/door product and have agreed the drawings/specifications and design, the product will be scheduled for manufacture. Your products will be delivered by a scheduled date through recorded delivery.

Other Window Ranges

Below is our top-level window range, custom windows are also available, call us to discuss.

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Below is our top level window range, custom windows are also available, call us to discuss.

    Get a Free Quote

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