Standard Window Sizes: Your Guide to Types & Measurements

Choosing the right windows for your home starts with understanding standard window sizes. Whether you’re building new or replacing old windows, knowing these measurements can save you time and money while ensuring a perfect fit.

Standard-size windows are pre-manufactured to fit common openings in modern homes. While custom windows are available for unique spaces, standard sizes typically cost about 50% less and arrive faster.

Understanding Window Size Notation

Window manufacturers use a simple four-digit code to identify sizes. The first two digits show width in feet and inches, while the last two show height. For example, a 2030 window measures 2 feet wide by 3 feet high, and a 3444 window is 3 feet 4 inches wide by 4 feet 4 inches high.

Double-Hung and Single-Hung Windows

Double-hung windows feature two movable sashes that slide vertically. The upper sash typically stays closed while the lower one opens for ventilation. Single-hung windows look identical but only the bottom sash moves—the top remains fixed.

Best Rooms for Installation

These versatile windows work beautifully in bedrooms, living rooms, and any space needing ventilation. Their easy-to-clean design from inside makes them ideal for upper floors. Single-hung versions suit ground-level rooms where exterior access is easier for maintenance.

Common Sizes

Double-hung windows are always taller than wide, with widths from 24 to 48 inches and heights from 36 to 72 inches:

• 2030 (2′ × 3′)

• 2044 (2′ × 4’4″)

• 2840 (2’8″ × 4′)

• 2852 (2’8″ × 5’2″)

• 4060 (4′ × 6′)

Sliding Windows

Sliding windows open horizontally, with one or both sashes moving side to side. They’re practical, space-efficient, and suit modern home designs.

Best Rooms for Installation

Install sliding windows in kitchens, bathrooms, basements, dining areas, or any room needing horizontal space efficiency. They’re perfect where vertical space is limited.

Common Sizes

Sliding windows are wider than tall or perfectly square, ranging from 36 to 84 inches wide and 24 to 60 inches high:

• 3020 (3′ × 2′)

• 3030 (3′ × 3′)

• 5030 (5′ × 3′)

• 6040 (6′ × 4′)

• 7040 (7′ × 4′)

Picture and Fixed Windows

Picture windows don’t open—they’re designed purely for views and natural light. This fixed design provides excellent insulation and energy efficiency. Aluclad windows are particularly popular for picture window installations, offering superior weather resistance, minimal maintenance, and lasting durability.

Best Rooms for Installation

Living rooms, hallways, stairwells, and any space where you want maximum natural light without needing ventilation. Picture windows create stunning focal points in your home.

Common Sizes

Picture windows offer the widest size range, from 24 to 96 inches in both dimensions:

• 3020 (3′ × 2′)

• 5030 (5′ × 3′)

• 6040 (6′ × 4′)

• 4050 (4′ × 5′)

• 8052 (8′ × 5’2″)

Casement Windows

Casement windows swing open like doors using a simple crank mechanism. They can feature single or multiple sashes and offer excellent ventilation control.

Best Rooms for Installation

Kitchens and bathrooms benefit most from casement windows due to superior airflow. They’re also ideal behind sinks or in hard-to-reach spots since the crank handle eliminates straining. Aluminium windows offer excellent casement options with exceptional durability, thermal performance, and low maintenance requirements.

Common Sizes

Casement windows typically range from 17 to 41 inches wide and 16 to 33 inches high:

• 1714 (1’7″ × 1’4″)

• 1725 (1’7″ × 2’5″)

• 2323 (2’3″ × 2’3″)

• 2929 (2’9″ × 2’9″)

• 3525 (3’5″ × 2’5″)

When You Need Custom Windows

Older homes and unique architectural designs often require custom measurements. While standard windows fit most modern constructions, custom options provide perfect solutions for non-standard openings.

Custom windows offer expanded size ranges—one manufacturer’s standard casement windows max out at 2’9″ high, but their custom versions reach 8 feet. You’ll also get precise measurements down to 1/8-inch increments for perfect fits.

Budget consideration: Custom windows typically cost 50% more than standard sizes, but they’re necessary for achieving proper fit and performance in non-standard openings.

Ready to Upgrade Your Windows?

Choosing the right window size impacts your home’s energy efficiency, comfort, and curb appeal. Whether you need standard or custom solutions, Expert Windows delivers quality products throughout Ireland.

Our team helps you select the perfect windows for your specific needs—from double-hung to casement, sliding to picture windows. We’ll guide you through measurements, styles, and installation to ensure your investment delivers lasting value.

Contact Expert Windows today for a free consultation and discover how the right windows can transform your home.