Ultimate Rose Sash Window

Ultimate Rose is the epitome of the Rose Collection design philosophy – outstanding aesthetics and exceptional performance. Ultimate Rose is, quite simply, the UK’s most authentic timber-alternative sash window. It redefines tradition.

We’ve re-engineered the timber-alternative sash window from the ground up, looking at every seam and detail that differed from a timber original and designing it out. The ultra-slim 35mm meeting rail, the seamless run-through sash horns and even the internal sash interlock – everything has been redesigned to achieve what no other timber-alternative sash window can; a smooth, seamless finish. The result is that even from close up only an expert can tell that it’s not timber.

Based around our innovative true mechanical jointing system, Ultimate Rose is built in exactly the same way as timber. There are no mitred welds or fake mechanical joints here, just simple, strong, joinery-style butt joints – horizontal on the frame and vertical on the sashes – just like a timber original.

The attention to detail matters. But while Ultimate Rose may look identical to traditional timber sash windows, the one place it’s designed to be different is in performance. ‘A’-rated energy efficiency, high security and independently tested sound insulation mean that not only will your home look great with Ultimate Rose, it will be warm, quiet and secure. Add all this together and you get a modern sash window that looks and performs better than anything else on the market.

Ultimate Vertical Sliding Sash Window

Technical Details

  • Maximum width: 1500mm
  • Maximum height: 3000mm
  • Frame depth: 137mm
  • Meeting rail: 35mm
  • Deep bottom rail: 81mm
  • Cill depths: 149mm and 225mm
  • Glazing: 28mm IGUs
  • WER energy rating: A

Standard Features

  • Profile detail: Putty line
  • Meeting rail: 35mm seamless (ultra slim)
  • Corner detail: True mechanical
  • Deep bottom rail: Standard
  • Sash horn: Seamless Run Through Horns
  • Astragal bars: Authentic
  • Furniture: Globe

Authentic Mechanical Joints

Manufactured using the methods as for joinery-built timber windows, Ultimate Rose has true end-sealed mechanical joints for perfect period authenticity.

What’s more, to enhance the distinct features of timber sash windows, Ultimate Rose is finished in a butt joint, which is horizontal on the frame and vertical on the sashes.

Seamless Midrail

To replicate the authentic look of timber sash windows, Ultimate Rose uses a significantly thinner meeting rails than most sash windows. At just 35mm, the midrail of the Ultimate Rose is as slim as you can get.


When selecting Ultimate Rose sash windows, a variety of colour and finishes allow you to match your windows perfectly to the style of your home. We offer wood effect options to provide a great replacement to timber windows, as well as any RAL colour, or with a unique chalked finish that imitates painted timber.

Please note, actual product colours may vary from the colours displayed on your monitor or device.

Please check a RAL colour chart before selecting a particular colour.

Standard Colours

Please contact us, if you are looking for a colour that is not shown below.

smooth white colour

Smooth White

white woodgrain colour

White Woodgrain

cream woodgrain colour

Cream Woodgrain

crystal white colour

Crystal White

Other Available Colours

The inside of the windows is white on the inside as standard, but, if you select any of the colours below as an external colour, you can colour match the inside of your window.

jet black colour

Jet Black

anthracite colour


slate colour


basalt colour


quartz colour


kensington colour


balmoral colour


painswick colour


cotswold cream colour

Cotswold Cream

chartwell green colour

Chartwell Green

brilliant blue colour

Brilliant Blue

Glazing Options

Our sash windows are A-rated for energy efficiency as standard, all being pre-glazed with soft coat glass and warm edge spacer bars. In addition to offering outstanding thermal performance, our range glazing options provide features specifically tailored to your needs.

Sash windows are available with toughened and laminated safety glass (including part Q compliant 6.8mm laminated), low iron glass, acoustic laminated glass and a range of obscure and patterned glass.

Browse our decorative glazing options

Astragal Bars

Optional Features

Sash Horn

Ultimate Rose sash windows are manufactured with seamless Run Through Horns as standard, but you have the option to upgrade to recently launched Seahorse Sash Horns.

For a simpler look, sash windows are also available without sash horns.

Deep cill

Ultimate Rose sash windows can be completed with standard or deep cills to fit the needs of every project.

Removeable Staff Bead

Ultimate Rose sash window achieves clean lines with a staff bead option. This can also be removed to allow for tilt functionality and easy cleaning.

Hardware Options

Globe Hook Lock

Globe window furniture is exclusively available with Ultimate Rose sash windows. To complement every project, you can select from a variety of colours.

Windows with a width of less than 700mm come with one hook lock, while windows with larger widths come with two hook locks.

Globe Furniture

Our Ultimate Rose sash windows are furnished with Ultimate Pole Eye (on left), Globe Tilt Knob (middle) and Ultimate Sash Lift (right). They are available in the same colours as the hook locks above.

Windows with a with of less than 700mm are made with one pole eye, and windows with a width of over 700mm are with two tilt knobs, two pole eyes on the top sash, and two sash lifts on the bottom sash.