Timber Box Sash Windows

Timber Box Sash Windows

A timber box sash window is the traditional sash that most people know.

Designed to replace the originals found in many Georgian and Victorian houses, weights & pulleys ensure the windows are easier to open, energy efficient, secure and soundproof without looking out of place for the style of the property.

As the whole process from design to manufacture is with Patchett Joinery, we can ensure the finished product accurately replicates the original style.

Our box sash windowoperates on sash cords, pulleys and sash weights.

  • Eco-Friendly Products
    Eco-Friendly Products
  • Extensive Guarantee
    Extensive Guarantee
  • Energy Efficient
    Energy Efficient
  • British Manufacturer
    British Manufacturer
Design Features


  • Weights and Pullies – traditional design where weights counter balances the weight of the sash.
  • Independently tested
  • Guaranteed performance
  • The smoothest operating sash window system
  • Internal beading
  • Double draught sealed to maximise thermal performance and weather proofing
  • Lockable fitch catch, traditional in its appearance, when closed it pulls the two sashes together to engage the seals fully


  • Traditional hardware with improved security options, concealed locking and travel restrictors
  • Safety restrictors to limit opening of sash, can be self-resetting
  • Concealed trickle ventilation – when required for new build situations our design conceals the trickle vent into the head of the frame, externally the vent is almost invisible and is concealed internally by the head rebate
  • Traditional sash lifts and sash eyes available in a large range of colour options
  • Vent lock – these devices provide additional security and peace of mind in that the window cannot be opened more than 100mm without them being removed
  • Angel lock – as with the vent lock, this device limits the travel of the sash. The advantage is, when the sash is subsequently closed, the device resets. When the sash is next opened, the restrictor stops the movement of the sash more than 100mm.

What are sash windows?

Timber box sash windows are often found in older homes. They are divided into 2, with the top and bottom parts sliding down or up to open. In many older properties, the sash windows are either loose and draughty or stuck with layers of paint and unopenable. Replacing sash windows with new versions of the original design can make for a much easier life and refresh the look of your property.

How do timber box sash windows work?

The reason they are called timber box sash windows is that the windows sit in a box frame that has the workings inside it. Traditionally, cords, weights and pulleys are used, allowing the windows to slide up and down smoothly. The weight of the window is counterbalanced with a on a cord which rolls over the pulley. We offer a choice of traditional weight and pulley sashes, pre-tensioned exposed balances, or our own concealed balance system.

No more draughts

If you’re used to draughty old sash windows you might be surprised by how well-sealed our new versions are. Our windows are double draught sealed, offering maximum thermal performance. You won’t find the wind and rain rattling through one of our windows. We make our sash windows with U values lower than the building regulations requirement. If it’s for a new build, we can include concealed trickle vents. We’ve designed it so the trickle vent is hidden in the head of the frame. It’s almost invisible from the outside and concealed by the head rebate on the inside.

Safe and secure

Even if you choose traditional hardware, we offer improved security for your windows. Concealed locking features mean you can secure your windows without an ugly-looking lock. We can also limit the opening of each sash, giving you peace of mind that there’s no danger of anyone falling out of a window. Safety restrictors can be self-resetting for ease of use.

Window designs

Our timber box sash windows are made bespoke to your specifications and we offer a huge range of paint colours as well as a large selection of glass types, and your choice of timber and hardware to suit your taste and decor.

Paint Process

first-primer2compressed patchett-joinery-paint-process-compressed

Using only a water-based painting system which allows timber to “breathe” and adapt to climatic changes, our finishes provide maximum protection against weathering, fungal attack and UV degradation. The water-based application significantly reduces harmful emissions and disposal issues associated with solvent based systems.

Working with our paint partner, Sikkens, we can finish in any RAL colour, stain, or match against all well known paint ranges and brands. With the ability to have different internal and external finishes, your windows and doors can be finished just as you require.

Our factory is audited quarterly to ensure that the finished product has the highest quality paint finish and performance you would expect.

Hardware Accessories
  • Ring Sash Lift

    Ring Sash Lift

  • Mighton Fitch Fastener Locking

    Mighton Fitch Fastener Locking

  • Croft Lockable Fitch Fastener

    Croft Lockable Fitch Fastener

  • Solid Sash Lift

    Solid Sash Lift

  • Cast Sash Lift

    Cast Sash Lift

  • Pressed Sash Lift

    Pressed Sash Lift

  • Push Lock

    Push Lock

  • Angel Lock

    Angel Lock

  • Round End Sash Stop

    Round End Sash Stop

  • Cill Lock

    Cill Lock

  • Solid Ring Pull Sash Lift

    Solid Ring Pull Sash Lift

  • Sliding Sash Fitch Fastner

    Sliding Sash Fitch Fastner

  • Sash Pullies

    Sash Pullies

  • Vent Lock

    Vent Lock

Timber Options
  • Accoya


  • Engineered Redwood

    Engineered Redwood

  • Red Grandis

    Red Grandis

Glass Options
  • Spacer Bars

    Spacer Bars

  • Planitherm Total+ and Low Emissivity (Low E) Glass

    Planitherm Total+ and Low Emissivity (Low E) Glass

  • Standard Glass

    Standard Glass

  • Toughened and Laminated Glass

    Toughened and Laminated Glass

  • Low Iron Glass

    Low Iron Glass

  • Wired/Fired and Pyro-Tech Glass

    Wired/Fired and Pyro-Tech Glass

  • Anti – Sun Glass

    Anti – Sun Glass

  • Acoustic Glass

    Acoustic Glass

  • Obscure Glass

    Obscure Glass

  • Decorative Glass

    Decorative Glass

  • Leaded Glass

    Leaded Glass

  • Gas


Technical Downloads and Product Brochure

Patchett Product Guarantee

All our timber box sash windows come with fantastic guarantees giving you the assurance that our products are made to last. All sash windows and doors we make and supply are engineered using the highest quality materials and will require minimum routine maintenance.

  • 30-year* manufacturer-backed guarantee against rot. (50 years with Accoya*)
    5-year* manufacturer-backed guarantee for paint on factory finished windows (Up to 12 years with Accoya*)
  • 10-year*manufacturer-backed guarantee on weather seals
  • 10-year*manufacturer-backed guarantee on double-glazed units
  • 5-year*manufacturer-backed guarantee on hardware