High-Performance Replacement Windows
Transform Your Home

Serving Brooklyn, Queens, Staten Island & Central New Jersey

Transform Your Home With Window Replacement

TopLine Home Improvement has been a leader in window replacement for homes in Brooklyn, Queens, Staten Island, and Central New Jersey since 1981. As a local, family-owned and operated replacement window company with an A+ Better Business Bureau rating and hundreds of five-star reviews, we understand which windows perform best on local homes. That’s why we offer OKNA replacement windows, which deliver a lifetime of enhanced curb appeal, energy efficiency, and performance.

Expert Window Installation & White-Glove Service

At TopLine Home Improvement, our window installation process ensures your new windows provide lasting performance, energy efficiency, and beauty.

Our OKNA-certified professionals deliver exceptional craftsmanship by carefully measuring, fitting, and sealing each window, guaranteeing optimal performance and longevity. With our exclusive white glove service, we manage every aspect of your installation—from initial consultation through final cleanup—ensuring your home remains spotless and your experience stress-free. Trust our highly trained team to treat your home with utmost care, delivering flawless results every time.

Premium OKNA Windows to Suit Your Needs & Budget

Enviro-Star (800 Series)
The premium Enviro-Star (800 Series) by OKNA represents the pinnacle of window technology, combining ultra-high efficiency HeatSeal glass with insulated frames for unparalleled energy savings. Engineered for maximum durability, security, and style, these windows drastically lower heating and cooling costs, offering the ultimate blend of luxury, performance, and sustainability for discerning homeowners.
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Casement (700 Series)
OKNA Casement (700 Series) windows deliver optimal ventilation and unobstructed views, operated smoothly by an easy-to-use crank mechanism. With superior weather stripping, advanced locking mechanisms, and robust construction, these windows offer unmatched protection against harsh weather, enhancing security while maintaining elegant aesthetics and efficient thermal performance for any home.
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Insul-Tec (500 Series)
OKNA’s Insul-Tec (500 Series) windows offer excellent thermal performance with advanced insulated frames and sashes. Engineered with a multi-chambered vinyl construction and optional foam insulation, these windows significantly improve energy efficiency, reduce noise, and maintain consistent indoor temperatures. Ideal for homeowners looking to balance comfort, energy savings, and affordability.
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OKNA Enviro-Star Windows—Incredible Performance at an Incredible Value

Air Infiltration

Air infiltration measures the volume of outside air passing through window joints or cracks. Measured in cubic feet per minute on a scale of 0 to 1, windows with lower numbers perform best.

OKNA Enviro-Star Windows have air infiltration rating of .01 cfm/ft, which is 2,000% better than the industry average.

U-Factor

U-factor measures how effectively windows prevent heat transfer, expressed. Lower numbers indicate better insulation and improved overall energy efficiency performance.

OKNA Enviro-Star Windows have U-ratings between .26 and .16.

Solar Heat Gain Coefficient

Solar Heat Gain Coefficient (SHGC) indicates how much solar radiation passes through windows, measured from 0 to 1. Lower ratings indicate reduced unwanted heat entry.

OKNA Enviro-Star Windows’s SHGC is .26 to .22

Design Pressure

Design pressure (DP) assesses window strength, resistance to wind pressure, and structural integrity, measured in pounds per square foot (psf); higher DP indicates greater durability.

OKNA Enviro-Star Windows can withstand winds of up to 187 mph.

Keystone Certified Replacement Windows

When you purchase a window or patio door that is advertised as the most energy efficient, you want to be sure the claims are based on facts, certified by a truly independent and objective authority.  

All OKNA windows and doors meet rigorous North American Fenestration Standard (NAFS). Certification is performed by The Keystone Certification Program.

Energy-Saving Features of OKNA Replacement Windows

OKNA replacement windows offer homeowners advanced technology designed specifically to maximize energy efficiency, minimize heating and cooling costs, and ensure year-round comfort. From durable construction to innovative insulation methods, these windows are an investment that significantly reduces energy bills while enhancing your home's overall thermal performance. Key features contributing directly to energy savings include:

  • Insulated uPVC Vinyl Frames and Sashes – Engineered with multiple insulating chambers, these frames and sashes greatly improve thermal performance and prevent energy loss.
  • HeatSeal Insulated Glass Unit (IGU) – This advanced glass unit provides superior insulation, significantly enhancing interior comfort and cutting down on long-term energy expenses.
  • Magnetic Seal – Creates an airtight closure, effectively blocking drafts and further reducing energy consumption.

OKNA Windows Thermal Performance Packages

HeatSeal Deluxe
  • Double-Pane Glass Unit
  • Low-E Glass
  • Argon Glass
  • Foam-Filled Extrusions
  • Locking Screen
  • U Factor: 0.26
  • SHGC: 0.26
  • Air Leakage: 0.01 cfm/ft
HeatSeal Triple Deluxe XR15
  • Double-Pane Glass Unit
  • Low-E Glass
  • Argon Glass
  • Foam-Filled Extrusions
  • Locking Screen
  • U Factor: 0.19
  • SHGC: 0.22
  • Air Leakage: 0.01 cfm/ft

HeatSeal Triple Deluxe XR10
  • Triple-Pane Glass Unit
  • Low-E Glass
  • Krypton Gas
  • Foam-Filled Extrusions
  • Locking Screen
  • U Factor: 0.16  
  • SHGC: 0.22
  • Air Leakage: 0.01 cfm/ft

A Wide Selection of Window Styles

Double-Hung Windows

The most common window style, double-hung windows give a traditional look to any home. These windows have two separate vertically adjustable sashes so they can easily be moved up & down for ventilation. The sashes interlock for great energy efficiency and they can tilt in, allowing you to easily and safely clean the window from inside your home.

Casement Windows

These windows have an adjustable sash that’s hinged from one side and opens outwards. The sash is controlled by an easy to use, fold in crank handle and is versatile, opening to a full 90-degree angle or less for easier cleaning and more ventilation options. A lever lock on the side of the window ensures an airtight seal between the sash & frame for exceptional energy efficiency.

Awning Windows

Awning windows provide a sash that’s hinged from the top and crank out from the bottom via an easy-to-use, fold-in handle. It opens to a 45-degree angle, giving it an awning-like profile and allowing for ventilation even when raining or snowing. Being a smaller size, awning windows are great for tight areas in a home where you want to obtain more sunlight and ventilation.

Bay & Bow Windows

These windows project outwards with an insulated head & seat board that has a furniture grade birch finish. A bay window provides a deeper projection of either 30- or 45-degree angles and comprises a choice of double-hung, casement, or picture windows. Bow windows are arranged with casement or picture windows, have a shallower projection of 10- or 15-degree angles.

Picture Windows

These windows offer a great choice for homeowners looking to make the most of their views and ensure optimal energy efficiency. Picture windows are typically larger and provide large, unobstructed views of the outdoors. They are known for their efficiency and durability, having a fixed sash and being without moving components like rails or mullions.

Hopper Windows

A popular style for basements or other tight areas of a home where you want to add sunlight and ventilation, hopper windows are hinged from the bottom and tilt 45 degrees by way of an easy-to-use, locking handle that gives an air-tight seal when closed. This style prevents dirt or other debris from entering a living area while brightening up a space with light and fresh air.

Horizontal Sliders

A popular style for basements or other tight areas of a home where you want to add sunlight and ventilation, hopper windows are hinged from the bottom and tilt 45 degrees by way of an easy-to-use, locking handle that gives an air-tight seal when closed. This style prevents dirt or other debris from entering a living area while brightening up a space with light and fresh air.

Custom Shaped Windows

These windows provide options for more dissimilar or different types of window openings in a home. Custom shaped windows are typically manufactured with either a stationary window sash, like a picture window, or a crank-out sash, like either a casement or awning window. Such windows lend a home greater distinction while securing more sunlight and possible ventilation.

Outstanding Warranties

Our warranty is simple and straight forward.

TopLine Home Improvement backs our products and workmanship with some of the best warranties in the industry, including true lifetime warranties against any defects in workmanship or material on our windows and doors. You can enjoy decades of guaranteed worry-free performance and style.

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Certified Quality and Energy Performance

Home Transformations