Double hung windows are similar to our single hung windows, except the top and bottom sash are both moveable, sliding vertically past each other and providing you with more choice in ventilation.

Both sash tilt inside for easy cleaning and servicing.

The classic look of a double hung window makes it a popular choice for new installations as well as retrofit applications.

Frame and Sash

  • Fiberglass profiles made from 65-85% glass fibers and 15-35% resin.
  • 82.5 mm deep (3”) frame and sash insulated with expanded polystyrene.
  • Frames made from pultruded fiberglass and assembled with tightly silicone sealed mitered corners with foam-filled reinforced and mechanically integrated nylon shear blocks.


  • Standard frame and aluminum brickmold color: White.
  • Additional colors can be viewed by clicking on 'Colors' located on the right side of the page. *
  • Split finishes are available. *

    * Subject to additional charges. Please contact your sales representative for additional information


  • Pre-tensioned heavy-duty Omega coil balance allows sash to tilted to the inside for cleaning and can be lifted out for service.
  • Pivot pin is die cast zinc; all parts rust resistant.
  • Injection moulded sash pulls allow for easy operation.
  • Zinc die cast lock provides security; two locks installed on windows wider than 1000mm or 39 3/8”.


  • Sealed insulated glass units conform to CAN/CSGB-12.8-M90.
  • Double glazing with a minimum 12.5mm (1/2”) air space is standard.
  • Glass thickness determined by the National Building Code, depending on size of window.
  • All glazing units manufactured with Super Spacer by Edgetech.
  • High performance glass options: spectrally selective day lighting glass, tinted glass, reflective glass, pyrolytic (hard coat) low emissivity glass and sputtered (soft coat) low emissivity glass.
  • Sealed unit held in place by a removable exterior aluminum glass stop while double-sided foam tape on the interior and thermoplastic rubber on the exterior help secure the glass and protect from the elements.


ENERGY STAR qualified products use less energy than conventional products, saving money and helping protect the environment.

As an ENERGY STAR Partner, Accurate Dorwin is proud to offer products with the ENERGY STAR label. For more information, please visit in the United States and Natural Resources Canada in Canada.


  • Exterior thermoplastic weatherstrip provides window with dust seal and some rain protection.
  • Center santoprene bulb seal prevents against air and water leakage; inner santoprene spline seal restricts air infiltration.
  • All seals, when used in conjunction with one another, allow cavities to be drained to the exterior to conform to the rain screen principle.
  • All weatherstripping can be replaced.


  • Factory installed full screen comes with all operable windows.
  • Roll formed aluminum screen frame held in place with compressor springs on one side.
  • Screening made from black, spline set non-glare fiberglass cloth.






  • Colors
  • Veneer
  • Brickmoulds

    Extruded aluminum brickmoulds with integral nailing fins are available. Brickmould will lock into face of frame and back with a windbreak that should be fastened into exterior sheathing without exposing nails or screws after applying exterior finish. Various brickmould profiles are available. Standard colors are White, Brown, Sandalwood and Hunter Green but custom colors are available.

  • Jamb Extensions

    Clear Fir Hemlock Oak and prefinished (White only) wood jamb extensions in various depths are available. Other wood jamb materials are available as options as determined by individual needs. A vinyl drywall return is also available.

  • Grills

    Grills add a touch of class to any piece of glass. Available in a range of colors in wood or fiberglass.

  • Simulated Divided Lites

    Simulated divided lites add personality to an otherwise bare window. Available in a number of styles.

CAD Drawings

CSI Format Specifications

Fiberglass Windows:
Guide Specifications.

To open .pdf files you will need Adobe Acrobat Reader

To open CAD Drawing files (.dwg) you will need a DWG viewer such as Brava DWG Viewer

To open document (.doc) files you will need Microsoft Word or a similar program. You can also download Microsoft Word Viewer for free.

*Accurate Dorwin is not responsible for any problems in relation to installing the above programs.