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    Sunspace Model 300 3-Season Sunroom

    Sunspace Model 300 3-Season Sunrooms in Maryland

    A bright glass 3-season room built from extruded aluminum, with double-roller windows that ventilate from both sides. Authorized Sunspace dealer.

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    4.9 stars on Google•101 Google reviews•MHIC #91686
    Sunspace Model 300 3-Season Sunrooms in Maryland

    About the Model 300

    A bright, low-maintenance glass sunroom

    The Model 300 is a glass 3-season sunroom that brings bright, comfortable space to your home. It is built from two inch extruded insulated aluminum pillars with single-glazed glass, which gives it strength, stability, and a virtually maintenance-free exterior. Aluminum-framed double roller windows ventilate from both sides, since both sashes operate with no fixed pane. Roof systems are flexible, from cathedral ceilings to contemporary studio pitch, over an existing deck or porch, or even a carport. As an authorized Sunspace dealer, we handle design, permitting, and factory-trained installation.

    • Two inch extruded insulated aluminum pillars with single-glazed glass
    • Double roller windows ventilate from both sides
    • Roof options: cathedral, studio pitch, over a deck, porch, or carport
    • Strong, stable, and virtually maintenance-free exterior
    • Colors: White, Black, Driftwood, Bronze, Gray
    • Bright natural light for a true three-season room

    Why Custom Design & Build

    A bright, durable 3-season glass room

    Bright Glass Room

    Single-glazed glass on extruded aluminum pillars for a clear, open feel.

    Two-Way Ventilation

    Both window sashes operate, so you can vent from the top, bottom, or both.

    Flexible Roof Options

    Cathedral, studio pitch, or attach over a deck, porch, or carport.

    Authorized Sunspace Dealer

    Factory-trained installation from design through finish.

    Recent Projects

    A few of our recent sunspace model 300 3-season sunroom builds

    Investment Guide

    What does this typically cost?

    $42,000 to $85,000 typical range

    Final pricing depends on your specific design, materials, and site conditions.

    Standard

    12' x 12' (144 sq ft), typically $42,000 to $55,000. Final price in your written proposal.

    Mid

    12' x 14' to 14' x 16', typically $45,000 to $68,000. Final price in your written proposal.

    Premium

    16' x 20' (320 sq ft), typically $68,000 to $85,000. Final price in your written proposal.

    Integrated railings add $2,500 to $5,000.

    See the full sunroom cost guide

    Get an Instant Estimate

    Frequently Asked Questions

    Common questions, clear answers

    How much does a Model 300 glass sunroom cost?
    A Sunspace Model 300 typically runs $42,000 to $55,000 for a 12' x 12' room up to $68,000 to $85,000 for a 16' x 20' room. Integrated railings add $2,500 to $5,000. You get a price bracket on the first phone call and a final written number after the site visit.
    What is a 3-season sunroom?
    A 3-season room is built for spring, summer, and fall use. It is not fully insulated for winter, but it gives you a bright, weather-protected space most of the year.
    Are the windows glass or vinyl?
    Single-glazed glass in aluminum-framed double roller windows.
    Can I use it in winter?
    The Model 300 is a 3-season room and is not fully insulated. For year-round comfort, see the Sunspace Model 400.
    What roof options are available?
    Cathedral ceiling, contemporary studio pitch, or attach over an existing deck, porch, or carport.
    How much maintenance does it need?
    Very low. The extruded aluminum exterior is virtually maintenance-free, just normal cleaning.
    Should I choose the Model 200 or Model 300?
    Both are three-season rooms, and at the same size they are usually within a few thousand dollars of each other. The Model 300 uses real glass for clarity and a traditional look. The Model 200's vinyl windows open up to 75 percent for more ventilation.
    Where do you install glass three-season sunrooms?
    Throughout Harford, Baltimore, Cecil, Anne Arundel, and Howard County, Maryland, from our Fallston office.
    What is the warranty?
    The Sunspace limited lifetime warranty covers laminations and finishes, glass breakage in windows and doors, vinyl extruded components, and hardware and screen units for as long as you own the room. Our installation is backed by our 2-year workmanship warranty, and we register the manufacturer warranty for you.

    What Homeowners Say

    Real feedback from Maryland homeowners

    "Mark was incredibly patient, walked us through every step of the process, and delivered a dream deck that exceeded our expectations. The deck was completed ahead of schedule. His crew was hard working, meticulous, and respectful."

    Marsha Cole

    Verified Google Review

    "Mark and his team are professional, detail oriented, and most of all, they LISTEN to you. So rare these days. Cannot recommend them highly enough."

    Jeffrey Buck

    Verified Google Review

    "We couldn't be happier with the beautiful deck and porch roof Custom Design and Build completed for us in Forest Hill. Their craftsmanship is top-notch, and they were always clear and consistent with communication."

    Kristen Volz, Forest Hill MD

    Verified Google Review

    Sunrooms near you

    Learning Center

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    Sunroom Windows: Vinyl vs Glass, and Which Is Right for You

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    How Much Does a Sunroom Cost in Maryland? 2026 Prices by Type and Size

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    Orientation, roof choice, Low-E glass, ventilation, ceiling fans, shading, and dedicated cooling: how to keep a glass room comfortable in July.

    Browse the full Learning Center

    Ready to Build?

    Let's talk about your outdoor space.

    Start with a free phone conversation. We'll learn about your project, answer your questions, and help you understand what's possible. No pressure, no high-pressure sales tactics.

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    4.9 stars on Google • 101 Google reviews • MHIC #91686 • Locally owned and operated