Timber Concealed Balance Sash Windows

Concealed Spiral Balance Sliding Sash Windows

Concealed spiral balance sliding sash windows are a great alternative to the traditional weights & pulleys sash window.

They are easy to use and meet the same quality standards, but tend to be more cost effective and ideal for new builds.

Instead of the weights & pulleys system, these windows use spiral rod torsion and tension springs in a self-contained balance for smooth and easy opening and closing.

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


  • Concealed balance system – the balances are only visible when the sashes are opened
  • Traditional hardware
  • Independently tested
  • Guaranteed performance
  • 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


  • Expose balance
  • Hidden balance – the weight of the sashes is supported on pre-tensioned springs that support the weight of the sash. Our hidden balance system means the white plastic balance tubes are hidden from view when the window is closed, especially attractive when heritage colours are used. This design requires a much smaller frame (or box) than W&P therefore requiring much less disruption in a refurbishment situation
  • 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.
Paint Process

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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
  • 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

  • Ring Sash Lift

    Ring Sash Lift

  • Mighton Fitch Fastener Locking

    Mighton Fitch Fastener Locking

  • Croft Lockable Fitch Fastener

    Croft Lockable Fitch Fastener

  • Vent Lock

    Vent Lock

Timber Options
  • Accoya


  • Engineered Redwood

    Engineered Redwood

  • Red Grandis

    Red Grandis

Glass Options
  • 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


  • Spacer Bars

    Spacer Bars

Technical Downloads and Product Brochure

Concealed Spiral Balance Sliding Sash Windows

Sashes are fitted with pre-tensioned spring balances providing equal tension perfectly matching the weight of the sash. Sliding sash windows are manufactured with an optional ‘secret lift’ mechanism with the balances hidden from view in the frame for a more aesthetically pleasing product.

Sash fastening uses a sweeping cam sash locking fitch and keep. Window furniture includes a traditional style sash lift and sash eye providing a means to operate the sash, whilst providing a decorative finish. Window furniture is available in chrome, brass or satin.

Patchett Product Guarantee

All our timber 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