Seattle Horizontal Sliding Windows
If you’re struggling with inefficient sliding windows that stick or slide slowly, Lake Washington Windows and Doors has the perfect solution. Call us today for window installation services in the Greater Seattle area. Our customers love the high-quality replacement windows we provide from the top industry-leading manufacturers.
Sliding Windows Defined
Sliding windows, sometimes called gliding or horizontal slider windows, are a type of sash window similar to single or double-hung windows. Rather than opening vertically, sliding windows open horizontally by sliding the sash from left to right or vice versa. Single sliding windows have one stationary sash and one operable sash, while double sliding windows have one and two operable sash.

We’ve Carefully Chosen The Best Manufacturers For Your Seattle Sliding Windows
We use our experience and industry knowledge to your benefit. With over 30 years in the window industry, time has allowed us to determine the replacement sliding window manufacturers who deliver the best blend of quality, price, and VALUE for you. Our chosen manufacturing partners create value in four essential areas:
- Consistency of quality and service over the years
- Level of warranty support to you
- Industry longevity
- Product innovation
Our valued manufacturer partners for sliding windows are:
Best Applications
- Excellent choice for rooms facing walkways, porches, and patios
- Great for bedroom windows and spaces with egress requirements.
- For those who find hand-crank windows more difficult to access than sliding windows
- Great source of natural light and ventilation
- Excellent low maintenance and easy-to-clean window style
- For those looking for a low-cost, operable window style
- Provide excellent security with lever and track locking systems
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LW Series Premium Vinyl Sliding Windows
LW Series sliding windows offer smooth, effortless operation with a sleek, symmetrical design that enhances your home’s curb appeal. Featuring advanced noise reduction, secure ventilation latches, and a durable Aluma-Force screen frame, these windows provide lasting comfort, peace, and style. With energy-efficient technology and thoughtful details, they blend elegance and performance for modern living.
Features and Benefits:
- High-quality rollers with precision bearings and stainless steel axles ensure effortless gliding for a lifetime.
- Even sightline frames provide a symmetrical appearance, enhancing your home’s curb appeal.
- Standard sound suppression technology reduces outside noise by up to 50% compared to typical dual-pane windows.
- Built-in ventilation latches allow for a semi-secure opening, letting in fresh air while maintaining safety.
- Aluma-Force heavy-duty insect screens, made with thick extruded aluminum walls, ensure longevity and easy removal.
Window Types | Energy Efficiency | Glass Packages | Noise Reduction | Design | Quality | Security | Warranty |
Single Slider | Comfort•Core™ | SunMatrix | Sound Package | Even Sightlines | Weather-Tight Seal | First Guard | Limited Double Lifetime |
Single Hung | Inner•Core™ | Infinit-e | Maximum View | Smooth Operation | Sash Dead Bolt | ||
Picture | SunShield | Ventilation Latch | Heavy-Duty Screen | Continuous Interlock | |||
Geometric | CoolShield | XTRU | |||||
Luminance | Armor | ||||||
QuadraTherm |
LW Series Double Sliding Vinyl Windows
LW Series double sliding windows are designed with two operable sashes that glide horizontally, providing enhanced ventilation and ease of use. Their even sightline frames offer a balanced, symmetrical appearance that complements your home architecture. Constructed with durable vinyl and advanced energy-efficient technology, LW Series double sliding windows provide long-lasting performance, comfort, and reduced energy costs.
Features and Benefits:
- Both sashes slide horizontally, providing enhanced ventilation and flexibility in airflow control.
- High-quality rollers and a constant-force stainless steel balance system ensure effortless and reliable window movement.
- Advanced glass packages exceed Energy Star® requirements, helping to reduce energy costs year-round.
- Proprietary titanium dioxide-infused vinyl extrusions are engineered for superior strength and longevity.
- Optional laminated security glass and solid stainless steel sash deadbolts offer increased protection against forced entry.
Window Types | Energy Efficiency | Glass Packages | Noise Reduction | Design | Quality | Security | Warranty |
Double Slider | Energy Star Certified | SunMatrix | Sound Package | Even Sightlines | XTRU | First Guard | Limited Double Lifetime |
Double Hung | Infinit-e | Tilt-In Feature | Smooth Operation | Sash Dead Bolt | |||
Casement | SunShield | Ventilation Latch | Easy Clean Glass | Continuous Interlock | |||
Awning | CoolShield | Armor | |||||
Bay & Bow | Luminance | ||||||
Garden | QuadraTherm |
Milgard Ultra Series fiberglass horizontal sliding windows are designed for exceptional energy efficiency, durability, and sustainability. These top-of-the-line windows feature eco-friendly fiberglass frames made primarily from silica sand, a naturally abundant resource. Unlike other materials, fiberglass expands and contracts at the same rate as the glass, reducing stress on the frame and ensuring long-term performance. Resistant to swelling, rotting, and warping, Milgard Ultra Series windows offer superior longevity while keeping your home comfortable year-round.
Features and Benefits:
- Extremely durable with an expected lifespan of nearly 80 years.
- Strong frame material allows for large custom sizes.
- Paintable frames that homeowners can update to match current home color trends.
- Low expansion/contraction rate through 100-degree temperature changes means less glass and caulking failure over time.
- An Energy Star package tailored to the Seattle region for optimal energy efficiency.
- Custom colors, hardware, and glass options to match any home design.
Configurations | Hardware Features | Color Options | Grid Options | Glass Textures | Tint Options | Screen Options |
Half-vent | Positive Action® Lock | Interior Colors | Interior Grids | Obscure Aquatex | Cardinal Low-E | Standard Mesh |
Half-vent above | Cam Lock (optional) | White (any exterior color) | Flat GBG Grid | Obscure Clear 42 | Solar Bronze | PureView Mesh |
Half-vent below | Sash Pull | Harmony (harmony exterior only | Sculptured GBG Grid | Obscure Delta Frost | Solar Gray | |
Single-vent | Bark (bark exterior only) | 3/4″ Vintage SDL | Obscure Frosted Glue Chip | |||
Double-vent | Black bean (black bean exterior only) | 1-1/8″ Vintage SDL | Obscure Glue Chip | |||
Half-vent below with gable above | Exterior Colors | 1-1/8″ Craftsman SDL | Obscure Matelux | |||
Half-vent below with 2-lites above | Frost | 1-1/8″ Legacy SDL | Obscure Narrow Reed | |||
Half-vent above with 2-lites below | Harmony | Exterior Grids | Obscure P516 | |||
Double-vent below | Bark | Flat GBG Grid | Obscure Rain | |||
Double-vent above with 3-lites below | Black bean | Sculptured GBG Grid | ||||
Double-vent below with 3-lites above | 3/4″ Vintage SDL | |||||
1-1/8″ Vintage SDL | ||||||
1-1/8″ Craftsman SDL | ||||||
1-1/8″ Legacy SDL |
COMMERCIAL-GRADE Installation
Leak Armor Lifetime Installation Guarantee
When it comes to preserving the lifespan of your new windows and doors, installation matters. Thousands of window and door installations have honed our replacement process to perfection. For each project, our team follows a streamlined 3-step process to ensure you experience minimal delays and inconvenience before enjoying the benefits of your new window or door.
Top-Rated Window & Door Replacement Services
At Lake Washington Windows and Doors, we offer the highest quality windows and unparalleled customer service, with over 800 5-star reviews. With each installation, our exclusive Leak Armor Installation provides superior protection around your window openings. When you choose us for your window installation project, you can be sure that you’re getting the best.
Financing Options with Convenient 10 Minute Approvals
In addition to special offers and promotions, ask our sales representative about our quick, digital financing application process. From low-interest traditional loans to no down-no payment-no interest deferred financing plans, we can help you fund your replacement window project so you can mobilize your cash for other investments. We are a proud partner of GreenSky, one of the largest lenders for the home improvement industry. See how much you can be pre-approved for.
Every Window & Door Includes a Limited Lifetime Warranty
The beauty of working with the top window manufacturers in the industry is the support you can expect before, during, and after installation. Milfard offers a limited lifetime warranty. However, the likelihood that you’ll need to take advantage of the warranties is low.
Milgard Lifetime Warranty Guarantee
Milgard’s award-winning windows and doors are built to last. However, if you ever encounter an unexpected problem, you can rest assured that their lifetime warranties cover your purchase.
Every Installation Includes Leak Armor Commercial-Grade Protection
Our exclusive Leak Armor protection is included with every window we install. Developed through thousands of customer installations and years of experience, we utilize multiple layers of flashing, pans, and sealants in a specific manner to provide commercial-grade sealing to residential homes.
FAQs: Replacement Sliding Windows
What’s the difference between vinyl and fiberglass sliding windows?
Vinyl windows are affordable, low-maintenance, and energy-efficient. They resist moisture and won’t peel or rot, making them a great budget-friendly option. However, they can expand and contract more with temperature changes.
Fiberglass windows offer superior durability, strength, and energy efficiency. They expand and contract at the same rate as glass, reducing stress on the frame and extending their lifespan. Fiberglass is also more resistant to warping and weather damage over time.
If you’re looking for long-term performance and strength, fiberglass is the better investment, while vinyl is a cost-effective, reliable choice. If you’re unsure which is right for you, our experts can help you compare options based on your home’s needs.
Do sliding windows require additional framing?
Horizontal sliding windows do not require additional framing as they can fit within the existing window frames. If you’re unsure about the size of your frame, don’t worry about it! Our team can assess the space and help you find the right size window to fit your needs.
Are sliding windows safe?
When it comes to home security, sliding windows are very secure. They often have multiple locking points and can be reinforced with the classic piece of wood in the sliding track. Depending on their placement, they can also be a safe choice for homeowners with small children if they cannot be easily reached.
How do I determine the size of the replacement window I need?
Don’t worry about the measurements! The first step in our replacement process is scheduling a convenient time for a window specialist to visit your home and complete a complimentary, no-sales-pressure consultation. During this time, we’ll inspect your old windows or doors and take measurements so you don’t have to.
How long does it take to install horizontal sliding windows?
The amount of time it takes to install new windows varies depending on the complexity and size of the project. However, we generally take 2-5 days to complete the installation.
How do sliding windows compare to other window designs regarding energy efficiency?
Sliding windows are highly energy efficient windows, especially when designed with insulated frames, low-E glass, and durable weather seals. While picture and casement windows offer a tighter seal, modern sliding windows minimize air leaks better than other designs.
How do sliding windows compare to single-hung and double-hung windows?
Sliding, single-hung, and double-hung windows each have their advantages depending on your needs. Sliding windows are a great choice for wider openings and easy operation. Single-hung and double-hung windows, which open vertically, are ideal for taller, narrower spaces and offer classic styling. While sliding windows have fewer moving parts, double-hung windows provide versatile ventilation options since both the top and bottom sashes can open.
Can sliding windows be used in a bay or bow window design?
Sliding windows aren’t typically used in bay or bow window designs, which usually feature fixed, casement, or double-hung windows for better ventilation and aesthetics. However, in some custom configurations, sliding windows can be incorporated into larger bay or bow window structures to provide a modern look and easy operation. Our team can help determine the best window styles for your space if you’re considering a bay or bow window.
Do you offer new construction windows?
Yes, please visit our Contractor Division for information and to get an estimate for New Construction windows.