Interstate's Bow and Bay windows elegantly add light and sun to any home.

Our products and processes emphasize energy savings – and that means we consume less energy to minimize the CO2 released into our environment.

Our buildings save energy by utilizing in-floor radiant heating during off-peak energy hours and by using motion controlled lighting.

Our processes conserve resources – like filtering and reusing glass wash water for glass rinsing, and recycling our vinyl and glass scrap created during the fabrication process. And of course, we have a recycling program for metals, cardboard and paper.

Interstate belongs to a voluntary energy cooperative that monitors and helps reduce energy usage during times of peak demand. We are helping to protect our community from blackouts, to keep energy rates stable and to help the environment by reducing reliance on peaking power plants.


Interstate’s Bow and Bay windows offers a unique weep system that directs water away from channels. It also has a maintenance free vinyl-clad exterior, available in white, adobe and bronze. With the optional copper roof, this window will bring a little bit of class to your home.


  • 3/4” #1 Eastern White Pine struts allow for a full spectrum of bow and bay designs.
  • 3/4” #1 Eastern White Pine end jambs (has secondary cover to hide unsightly installation nails and screws).
  • Two interior finishes – vinyl or all wood mullions, end fillers, and stops.
  • Unique weep system directs water away from channels.
  • 1/4” all-threaded steel rods between struts tie head and seat boards together for added strength.
  • Foam sealant between struts for added energy efficiency.
  • Maintenance free vinyl-clad exterior – available in white, clay and bronze.
  •  All plywood insulated head and seat board in birch or oak.
  • Turnbuckle support kit includes chain, turnbuckles and hooks recommended for added strength.
  •  Low pressure polyurethane foam sealant between struts for best thermal performance.
  • Available with stain matching head, seat board and edge banding.
  • Fully assembled shell.
  • Windows are purchased and easily installed separately into frames.
  • Optional custom metal roofs available. Contact us today!
Interior & Exterior Solid Vinyl Colors
Interior Stock Laminate Woodgrains
Custom Paint Finishes (14 in Stock Exterior Colors)
Unlimited Color Match Exterior Colors.
Custom blended colors available to suit your design needs – limited only by your imagination!

Incredible Thermal Values

Dual Glazed
  • Standard Whole Window NFRC Certified Dual
    Energy Saver Glass Package
    Nominal 3/4”
  • U-Factor:
    Double Hung & Slider- .26
    Low E + clear; argon
  • With Energy Saver IS – .23
    Low E + Low E inside surface; argon
Fuel Saver™
  • Standard Whole Window NFRC Certified Triple Glazed
    Glass Packages
    Nominal 1 1/8”Triple Fuel Saver
    Double Hung & Slider- .20
    Low E + Low E + clear; argon + argonTriple Fuel Saver Plus
    Double Hung & Slider – .17
    Low E + Low E + clear; argon + argon
    and/or krypton

Climaguard™ Low E Glass and Argon Gas Add Comfort and Energy Savings

Low E is a transparent metallic oxide coating applied onto a glass surface. The coating allows short-wave energy to pass through but reflects long-wave infrared energy, which lowers the U-value and that means more energy savings. An odorless, colorless, tasteless, non-toxic gas, argon is six times denser than air. It is used to replace air between the glass panes to reduce thermal energy transfer and heat loss.

ClimaGuard glass has heat reflective coatings – microscopically thin layers of metal and metal oxide that filter energy by keeping warmth inside in winter and outside in summer.

Built Tough Hardware

All Interstate vinyl windows come standard with the industry’s finest hardware system. The operators, locks, and hinges have all been developed to work together to meet or exceed maximum performance requirements. Interstate provides the strongest, most attractive, easiest operating and highest performing hardware in today’s market.

Double Hung Locks
Casement Cranks and Slim Line Locks
Grid Options

Grids bring a distinctive look to your home. Four grid styles in a variety of color and style combinations offer many choices when selecting grids for your windows. Grids Between Glass (GBG) afford easy cleaning, Applied Surface Grids (ASGs) are permanently adhered to the panes inside and out and are designed to look like a true multi-paned window.

Bow & Bay Window Grid Color Options

Flat Colonial

  • White
  • Clay
  • Bronze ext./White int.
  • Custom Painted*

Contoured Colonial

  • White
  • Clay
  • Bronze ext./White int.
  • White ext./Woodgrain Laminate int.

SDL – Simulated Divided Lites: Colonial Contour

  • White int/ext
  • Clay int/ext
  • Bronze ext./White int.
  • White ext./Woodgrain Laminate int.
  • Custom Painted*

*Only Flat and Applied Surface Grids can be custom painted.

Sample Grids