Core Series

Width of the overall glass unit is 1 3/8" top rating in energy efficiency.

Ostaco Windows and Doors Core Series - 1 

Core Construction:

  • Ostaco Windows and Doors Core Series - 2Multi-chambered design reduces exterior noise, adds insulation and strength and provides thermal efficiency.
  • Multiple weather-stripping provides outstanding protection against the elements.Up to 5 weatherstrips help reduce heating and cooling costs.
  • Screen channel designed for screen removal from inside your home.Half screen and full screen are available.
  • Welded frame and sash corners provide strength and protection against air and water infiltration.
  • Snap-in interior glazing bead allows easy replacement of glass from the inside.
  • Double-walled sash design for superior strength.
  • Excellent drainage system evacuates the heaviest rains.
  • Provision to add windbreak to cut down on air infiltration.
  • Extra thick wall design for improved rigidity.
  • Interior groove allows the addition of mouldings such as 3/4" wood return, wood jambs or all u-PVC jamb extension.
  • Provision for installation brackets.
  • Tilt option available for easy cleaning
  • New Ostaco "inLighten" screen is available.

Core Single Hung/Single Slider Performance Ratings

Series Core Core Plus
Air Infiltration Resistance A3 A3
Water Infiltration Resistance B4* B3
Wind Load Resistance C3 C4
Forced Entry Resistance F2 F2


Core Series and Core Plus Series windows are Energy Star approved. Performance chart by USWADA.


Core Series
Single Slider & Single Hung Windows

Ostaco Windows and Doors Core Series - 3


This is perfect for older households with 2x4 construction, as our Core Series is designed to fit thinner 3 1/4" wall construction.


  •  3 ¼" frame

Wood Extension Options

  • Available with a wide variety of wood extensions from pine to oak.


  • White, or exterior painted in your choice of colour.

Performance Rating

  • Energy Star approved.

Glass options

  • Standard Low E2;
  • our latest comfort technology LowE3;
  • or our new Low E 179c
    (the best ER rating in the entire world!).


  • A wide range of decorative grilles and energy-smart glazing options are available to give your window a custom-designed look.