Coeur d'Alene 1242 Single-Hung Window (2-wide mulled configuration)

The Coeur d’Alene 1242 delivers one of the few vinyl windows with side-load removable sashes that provide stronger frames than typical tilt-in designs. Steel reinforcement provides more strength than vinyl, wood, or composite framing alone. For Montana contractors dealing with temperature swings from -20°F to 90°F, that structural advantage matters. The 2 3/4” frame width makes it compatible with aluminum window replacement — a common retrofit scenario across the state.

Energy Performance for Montana’s Climate Zones

U-values range from .24 to .30 depending on glass package, with SHGC ranging from .22 to .30. Those numbers put this window squarely in code-compliance territory for Montana’s Climate Zone 6. Cardinal IG Glass comes standard with multiple Low-E options including LoE3-366 (high performance) and LoE3-270 (standard performance), plus argon gas fill.

Specification	Value	Source
U-Value Range	.24 to .30	manufacturer
SHGC Range	.22 to .30	manufacturer
Glass Options	Cardinal IG with Low-E	manufacturer
Gas Fill	Argon standard	manufacturer
Performance Grade	LC PG-40	manufacturer

The Endur IG Spacer uses polyisobutylene and silicone seals, backed by Cardinal’s dual seal system for moisture permeation resistance. That’s condensation prevention technology — crucial when Montana winter nights drop below zero and indoor humidity meets cold glass.

Structural Design and Size Flexibility

The 2-wide mulled configuration handles up to 50 square feet total area with maximum width of 96 inches. Minimum width sits at 18.5 inches, minimum height at 28.375 inches. Those dimensions give contractors flexibility for large openings without compromising the AAMA LC PG-40 performance rating.

Welded corners reduce moisture intrusion — a detail that matters when spring snowmelt and summer thunderstorms test every seal. Steel reinforced interlocks add structural stability beyond what unreinforced vinyl can deliver. Optional foam-filled frames improve both thermal and structural performance.

Installation Requirements

Professional installation by certified installers (FGIA/Installation Masters, OSI, AWDI) is strongly recommended. Install in accordance with AAMA guidelines — AAMA-2400-02 for new construction, AAMA 2410-13 for flush-fin. Specific instructions for painted/Carbon products must be followed to avoid heat distortion.

The 2 3/4” frame width compatibility with aluminum window replacement opens up retrofit opportunities without major framing modifications. Various exterior finishes include White, Adobe, Bronze, and Black.

The Bottom Line

Side-load sashes beat tilt-in designs for frame strength. Steel reinforcement handles Montana wind loads. Energy numbers meet code requirements. The 50-square-foot maximum for mulled units covers most residential openings. At U-values between .24 and .30, these windows deliver solid thermal performance for Montana’s heating-dominated climate.

Compatible with new construction framing or aluminum replacements, the 1242 works for both new builds and retrofits. Certified to AAMA and NFRC standards, with ENERGY STAR options available for .20 and .24 U-value requirements. For contractors who understand that frame strength matters as much as glass performance, this window delivers both.

Frequently Asked Questions

What makes the side-load sash design stronger than tilt-in windows? Side-load removable sashes create a stronger, more resilient frame than typical East Coast tilt-in designs. The frame doesn’t need the compromises that tilt mechanisms require, resulting in better structural integrity.

Can these windows meet Montana’s strictest energy codes? With U-values as low as .24 and ENERGY STAR options available for .20 and .24 U-value requirements, they’ll meet code requirements across Montana’s Climate Zone 6.

What’s the largest opening I can create with the 2-wide mulled configuration? Maximum area is 50 square feet with maximum width of 96 inches for double single-hung units. That covers most residential applications.

Do these windows require special installation procedures? Professional installation by FGIA/Installation Masters, OSI, or AWDI certified installers is strongly recommended. Proper sill support and use of systems like OSI Quad Window & Door System are recommended.