The Classic Series is Thermo-Tech's new construction line: vinyl windows with an integral nailing flange, installed per Thermo-Tech's published new construction instructions. Thermo-Tech describes the series as built with premium grade materials for energy efficiency, safety and security.
Classic Series windows ship standard with double-pane insulated LoE2-272 argon glass, with LoE3-366 argon and the Energy Guard triple-pane packages as upgrades. Because they are built to order in Sauk Rapids, they also fit additions and full-frame replacements where the siding comes off.
On a Twin Cities addition we flash the nailing flange to the housewrap and order the Energy Guard package where the room will be used in winter.
Highlights
- Integral nailing flange for new construction installation
- LoE2-272 argon double-pane glass standard
- LoE3-366 and Energy Guard triple-pane upgrades
- Built to order in Sauk Rapids, Minnesota
- Fits additions and full-frame replacements
- Limited lifetime warranty on frame, sash and hardware
Available styles
Insulation and energy performance in Minnesota
Classic Series windows come standard with LoE2-272 argon glass, already a cold-climate coating, and can step up to Energy Guard triple-pane. For a Minnesota addition or new build, order Energy Guard for bedrooms and the north and west sides and flash the flange so the frame insulation is not undone by air leaks.
Glass packages
- Standard: double-pane insulated LoE2-272 argon glass
- LoE3-366 argon double-pane upgrade
- Energy Guard PLUS: triple-pane with LoE2-272 on two surfaces, two half-inch argon spaces
- Energy Guard: triple-pane with LoE3-366 on two surfaces, argon-filled
- Duralite warm-edge spacer
- Obscure and tempered glass available
Frame and sash
Vinyl frame and sash with an integral nailing flange, built to order in Sauk Rapids; woodgrain interior laminates available with White or Sandlewood exteriors.
Ratings
Thermo-Tech publishes performance data by unit at ttwindows.com; specify the Northern-zone ENERGY STAR glass when ordering.
What the install adds
On install day we set the unit on a sill pan, tape the nailing fin or frame to the housewrap, fill the rough-opening gap with low-expansion foam, and finish the interior with backer rod and sealant so the air barrier is continuous. Exterior joints get backer rod and a quality sealant, so the rating on the label is what you feel in the room.
Classic Series New Construction Windows at a glance
- Exterior colors
- Three vinyl colors including White and Sandlewood, plus exterior paint finishes
- Interior options
- Matching vinyl; woodgrain laminates with White or Sandlewood exteriors
- Glass
- LoE2-272 argon standard; LoE3-366 argon; Energy Guard and Energy Guard PLUS triple-pane
- Spacer
- Duralite® warm-edge spacer
- Grilles
- Flat grids between the glass
- Installation
- New construction with nailing flange; additions; full-frame replacement
- Warranty
- Limited lifetime on frame, sash parts and hardware per Thermo-Tech literature; glass and laminate terms are shorter, confirm the current warranty at ordering
- Where sold
- Thermo-Tech dealers in the Upper Midwest
- Made in
- Sauk Rapids, Minnesota
Product details summarized from the manufacturer's published materials, last checked 2026-10-09. Options, specifications, and availability vary by configuration and change over time — we'll confirm current options and pricing for your project at your free estimate.
