Quick answer
Window installation services in Maryland fall into three groups: full replacement contractors, broader exterior remodelers, and glass-repair specialists. This guide compares ten existing Maryland-area companies by project type and location, then explains how to verify licensing, product labels, installation scope, lead-safe practices and written warranty terms before requesting quotes.
Reviewed and substantially updated: September 3, 2026
Editorial disclosure: Companies remain in the original published order. Inclusion is not an endorsement, and advertisers cannot purchase editorial rank. Sponsored placements and paid links are labeled.
Editorial disclosure: Companies remain in the original published order. Inclusion is not an endorsement, and advertisers cannot purchase editorial rank. Sponsored placements and paid links are labeled.
Quick comparison: 10 Maryland window companies
| Company | Maryland base / area | Primary project fit | Phone |
|---|---|---|---|
| Capitol Improvements | Gaithersburg; MD, DC and Northern Virginia | Replacement windows and exterior remodeling | 301-769-6991 |
| Roland Slate Service Co. | Baltimore and nearby counties | Roofing and historic exterior work; verify window scope | 410-532-9037 |
| Window Nation | Maryland-founded, multi-market provider | Residential replacement windows and doors | 410-766-8488 |
| Thompson Creek Window Company | Lanham / Mid-Atlantic | Replacement windows, doors and exterior products | 240-660-3336 |
| Kelemer Brothers | Maryland, DC and Northern Virginia | Replacement windows plus doors and siding | 410-299-0038 |
| Premier Windows & Glass | Rockville and DC metro | Glass repair, window repair and full replacement | 301-244-8406 |
| Obrebski Brothers | Nottingham / Baltimore metro | Replacement windows, doors and siding | 410-497-9267 |
| Hodges Window & Glass | Middle River and Forest Hill | Window glass, screens and custom glass repair | 410-686-1389 |
| Top Value Glass & Window Repair | Germantown and DC metro | Glass/window repair plus replacement projects | 301-605-0955 |
| Liberty Roofing Window & Siding | Columbia; MD, DC and Virginia | Window installation and broader exterior remodeling | 410-715-1232 |
Contact details and service descriptions were checked against company websites for this September 3, 2026 update. Availability, service areas and phone routing can change, so confirm details directly.
The list distinguishes full replacement from repair. A company that replaces insulated glass or hardware may fit a failed pane, while a deteriorated frame, leaking opening or major remodel may require a full-frame installer.
How we reviewed these window installation services
1. Kept the original ten companies. We corrected names and clarified category fit instead of silently replacing the list.
2. Checked current official sources. Service descriptions, locations and contact details were reviewed against company websites available during this update.
3. Matched each company to project type. Replacement installers, exterior remodelers and glass-repair specialists are labeled so readers can build a sensible quote list.
4. Added a homeowner verification framework. Maryland licensing, written scope, product labels, lead-safe rules and warranty terms matter more than marketing claims.
5. Preserved editorial independence. We do not claim first-hand testing and do not treat paid relationships as evidence of quality.
2. Checked current official sources. Service descriptions, locations and contact details were reviewed against company websites available during this update.
3. Matched each company to project type. Replacement installers, exterior remodelers and glass-repair specialists are labeled so readers can build a sensible quote list.
4. Added a homeowner verification framework. Maryland licensing, written scope, product labels, lead-safe rules and warranty terms matter more than marketing claims.
5. Preserved editorial independence. We do not claim first-hand testing and do not treat paid relationships as evidence of quality.
This is a comparison starting point, not a certification of workmanship. Verify the contracting entity through the Maryland Home Improvement Commission license search, review the state’s consumer advice for home-improvement contracts, and obtain multiple written proposals.
The 10 window installation and repair companies
1. Capitol Improvements
Best fit: Full replacement windows with a local exterior-remodeling contractor.
Verified company snapshot: Its official site presents window replacement alongside doors, roofing and siding, with a Gaithersburg base and service across Maryland, Washington, DC and Northern Virginia.
Why it may fit: Useful when a window project may overlap with other exterior work or when comparing several window materials and styles.
Confirm before hiring: Ask whether the quote is insert or full-frame installation, which opening repairs are included, and who provides the labor warranty.
Location: Gaithersburg, Maryland
Phone: 301-769-6991
Visit the official company website
Verified company snapshot: Its official site presents window replacement alongside doors, roofing and siding, with a Gaithersburg base and service across Maryland, Washington, DC and Northern Virginia.
Why it may fit: Useful when a window project may overlap with other exterior work or when comparing several window materials and styles.
Confirm before hiring: Ask whether the quote is insert or full-frame installation, which opening repairs are included, and who provides the labor warranty.
Location: Gaithersburg, Maryland
Phone: 301-769-6991
Visit the official company website
2. Roland Slate Service Co.
Best fit: Historic exterior, roof, gutter, masonry or chimney projects where the company can confirm a relevant window scope.
Verified company snapshot: The current official site focuses on roofing, slate, copper, gutters, masonry, chimneys and historic exterior work. It does not clearly present standard replacement-window installation as a core service.
Why it may fit: It may be relevant for complex exterior-envelope or historic-home work where openings interact with flashing or masonry.
Confirm before hiring: This is a category-fit caution. Ask the company to confirm in writing that it performs the exact window work needed. If not, compare a window specialist.
Location: Baltimore, Maryland
Phone: 410-532-9037
Visit the official company website
Verified company snapshot: The current official site focuses on roofing, slate, copper, gutters, masonry, chimneys and historic exterior work. It does not clearly present standard replacement-window installation as a core service.
Why it may fit: It may be relevant for complex exterior-envelope or historic-home work where openings interact with flashing or masonry.
Confirm before hiring: This is a category-fit caution. Ask the company to confirm in writing that it performs the exact window work needed. If not, compare a window specialist.
Location: Baltimore, Maryland
Phone: 410-532-9037
Visit the official company website
3. Window Nation
Best fit: Homeowners seeking a replacement-window company with a broad product range and multi-market operations.
Verified company snapshot: Window Nation describes itself as a replacement-window and door company. Its official materials say it opened its first Maryland showroom in 2006 and later expanded to multiple markets.
Why it may fit: Useful for whole-home replacement comparisons where product configuration, financing and scheduling matter.
Confirm before hiring: Confirm the local branch serving your ZIP code, exact product line and NFRC label, crew arrangement, installation method and written labor coverage.
Location: Maryland service area; confirm nearest branch
Phone: 410-766-8488
Visit the official company website
Verified company snapshot: Window Nation describes itself as a replacement-window and door company. Its official materials say it opened its first Maryland showroom in 2006 and later expanded to multiple markets.
Why it may fit: Useful for whole-home replacement comparisons where product configuration, financing and scheduling matter.
Confirm before hiring: Confirm the local branch serving your ZIP code, exact product line and NFRC label, crew arrangement, installation method and written labor coverage.
Location: Maryland service area; confirm nearest branch
Phone: 410-766-8488
Visit the official company website
4. Thompson Creek Window Company
Best fit: Mid-Atlantic homeowners comparing a company that sells and installs replacement windows and other exterior products.
Verified company snapshot: Thompson Creek’s official site markets replacement windows, doors, siding and roofing for the Mid-Atlantic and identifies Maryland operations.
Why it may fit: The single-company sales and installation process may appeal to homeowners who want one point of contact.
Confirm before hiring: Request product specifications, NFRC label values, installation method, exclusions, cancellation terms and separate product and labor warranty documents.
Location: Lanham, Maryland / Mid-Atlantic
Phone: 240-660-3336
Visit the official company website
Verified company snapshot: Thompson Creek’s official site markets replacement windows, doors, siding and roofing for the Mid-Atlantic and identifies Maryland operations.
Why it may fit: The single-company sales and installation process may appeal to homeowners who want one point of contact.
Confirm before hiring: Request product specifications, NFRC label values, installation method, exclusions, cancellation terms and separate product and labor warranty documents.
Location: Lanham, Maryland / Mid-Atlantic
Phone: 240-660-3336
Visit the official company website
5. Kelemer Brothers
Best fit: Replacement windows for homeowners who also may need doors or siding in Maryland, DC or Northern Virginia.
Verified company snapshot: The correct company name is Kelemer Brothers. Its current site lists window replacement, doors and siding, says the family business began in 1999 and identifies its regional service area.
Why it may fit: A locally focused option for comparing window configurations and related exterior upgrades.
Confirm before hiring: Confirm the proposed manufacturer and series, whether full-frame work is needed, and what trim, caulk, insulation and disposal are included.
Location: Maryland, DC and Northern Virginia
Phone: 410-299-0038
Visit the official company website
Verified company snapshot: The correct company name is Kelemer Brothers. Its current site lists window replacement, doors and siding, says the family business began in 1999 and identifies its regional service area.
Why it may fit: A locally focused option for comparing window configurations and related exterior upgrades.
Confirm before hiring: Confirm the proposed manufacturer and series, whether full-frame work is needed, and what trim, caulk, insulation and disposal are included.
Location: Maryland, DC and Northern Virginia
Phone: 410-299-0038
Visit the official company website
6. Premier Windows & Glass
Best fit: Projects that may be solved by glass or window repair instead of automatic whole-window replacement.
Verified company snapshot: Premier’s official site lists insulated-glass replacement, window and door repair, and full replacement. It identifies a Rockville location and a Springfield, Virginia warehouse.
Why it may fit: Its repair menu can help homeowners compare the least invasive reasonable scope before replacing an entire unit.
Confirm before hiring: Ask whether the problem is limited to glass, hardware, sash or seal failure, or whether the frame and opening require replacement. Get both options itemized when practical.
Location: Rockville, Maryland
Phone: 301-244-8406
Visit the official company website
Verified company snapshot: Premier’s official site lists insulated-glass replacement, window and door repair, and full replacement. It identifies a Rockville location and a Springfield, Virginia warehouse.
Why it may fit: Its repair menu can help homeowners compare the least invasive reasonable scope before replacing an entire unit.
Confirm before hiring: Ask whether the problem is limited to glass, hardware, sash or seal failure, or whether the frame and opening require replacement. Get both options itemized when practical.
Location: Rockville, Maryland
Phone: 301-244-8406
Visit the official company website
7. Obrebski Brothers Windows and Doors
Best fit: Baltimore-area replacement windows, doors or siding with a local showroom option.
Verified company snapshot: The official site presents the family company as a window, door and siding contractor serving the Baltimore metro area and lists an appointment showroom in Nottingham.
Why it may fit: A practical local comparison for homeowners who want to see samples and discuss window and door work together.
Confirm before hiring: Verify the MHIC license under the exact contracting entity, proposed window series, crew arrangement, opening repairs and warranty-service process.
Location: Nottingham, Maryland
Phone: 410-497-9267
Visit the official company website
Verified company snapshot: The official site presents the family company as a window, door and siding contractor serving the Baltimore metro area and lists an appointment showroom in Nottingham.
Why it may fit: A practical local comparison for homeowners who want to see samples and discuss window and door work together.
Confirm before hiring: Verify the MHIC license under the exact contracting entity, proposed window series, crew arrangement, opening repairs and warranty-service process.
Location: Nottingham, Maryland
Phone: 410-497-9267
Visit the official company website
8. Hodges Window & Glass
Best fit: Broken panes, fogged insulated glass, screens, storefronts and custom-glass work.
Verified company snapshot: Hodges’ current website emphasizes residential and commercial glass services, including window glass repair, panes, screens, storefront and custom glass, with locations in Middle River and Forest Hill.
Why it may fit: A useful comparison when the frame may be serviceable and the immediate need is repair rather than whole-window replacement.
Confirm before hiring: Ask whether the quote is glass-only or a complete replacement unit. Confirm energy-performance labels if a new window is proposed.
Location: Middle River and Forest Hill, Maryland
Phone: 410-686-1389
Visit the official company website
Verified company snapshot: Hodges’ current website emphasizes residential and commercial glass services, including window glass repair, panes, screens, storefront and custom glass, with locations in Middle River and Forest Hill.
Why it may fit: A useful comparison when the frame may be serviceable and the immediate need is repair rather than whole-window replacement.
Confirm before hiring: Ask whether the quote is glass-only or a complete replacement unit. Confirm energy-performance labels if a new window is proposed.
Location: Middle River and Forest Hill, Maryland
Phone: 410-686-1389
Visit the official company website
9. Top Value Glass & Window Repair
Best fit: Residential or commercial glass repair, fogged-window service, storefront work and selected replacement projects.
Verified company snapshot: The official site lists broken and fogged window repair, glass replacement, new window and door replacement, storefront service and emergency work across Montgomery County, Washington, DC and Northern Virginia.
Why it may fit: Useful for diagnosing whether a repair can address the problem and for projects involving residential glass or commercial openings.
Confirm before hiring: Confirm emergency pricing, whether the quote covers glass only or the full window, permit responsibility and the exact repair warranty.
Location: Germantown, Maryland
Phone: 301-605-0955
Visit the official company website
Verified company snapshot: The official site lists broken and fogged window repair, glass replacement, new window and door replacement, storefront service and emergency work across Montgomery County, Washington, DC and Northern Virginia.
Why it may fit: Useful for diagnosing whether a repair can address the problem and for projects involving residential glass or commercial openings.
Confirm before hiring: Confirm emergency pricing, whether the quote covers glass only or the full window, permit responsibility and the exact repair warranty.
Location: Germantown, Maryland
Phone: 301-605-0955
Visit the official company website
10. Liberty Roofing Window & Siding Inc.
Best fit: Residential or commercial window installation that may be bundled with siding, roofing or doors.
Verified company snapshot: Liberty’s official site lists window replacement and installation, identifies a Columbia address, and says it serves Maryland, Washington, DC and Virginia.
Why it may fit: A broad exterior-remodeling comparison where window detailing must coordinate with siding or other envelope work.
Confirm before hiring: Confirm the legal entity and MHIC record, product model, insert versus full-frame method, flashing and sealing details, schedule and warranty exclusions.
Location: Columbia, Maryland
Phone: 410-715-1232
Visit the official company website
Verified company snapshot: Liberty’s official site lists window replacement and installation, identifies a Columbia address, and says it serves Maryland, Washington, DC and Virginia.
Why it may fit: A broad exterior-remodeling comparison where window detailing must coordinate with siding or other envelope work.
Confirm before hiring: Confirm the legal entity and MHIC record, product model, insert versus full-frame method, flashing and sealing details, schedule and warranty exclusions.
Location: Columbia, Maryland
Phone: 410-715-1232
Visit the official company website
How to compare window installation quotes in Maryland
1. Diagnose repair versus replacement. Fogged insulated glass, broken hardware or a damaged screen may not require a whole new frame. Rot, chronic leakage, poor opening geometry or a major remodel can point toward full-frame work.
2. Ask for the installation method. An insert or pocket unit generally fits within an existing frame. Full-frame replacement removes more of the existing assembly and exposes the rough opening. Have each bidder explain why its method fits the condition.
3. Verify the contractor. Search the exact business name and make sure the written contract identifies permits, subcontractors and cleanup.
4. Compare products with labels, not adjectives. Ask for the manufacturer, series, frame material, glass package and NFRC label values.
5. Itemize the opening work. The proposal should cover removal, hidden-damage repairs, flashing, air and water sealing, insulation, trim, disposal and touch-up work.
6. Separate warranty documents. Product and installation-labor coverage are different. Request both in writing, including exclusions, transfer rules, service fees and claim steps.
7. Plan for older homes. For paid work that disturbs painted surfaces in many pre-1978 homes, ask how the firm complies with EPA lead-safe rules.
2. Ask for the installation method. An insert or pocket unit generally fits within an existing frame. Full-frame replacement removes more of the existing assembly and exposes the rough opening. Have each bidder explain why its method fits the condition.
3. Verify the contractor. Search the exact business name and make sure the written contract identifies permits, subcontractors and cleanup.
4. Compare products with labels, not adjectives. Ask for the manufacturer, series, frame material, glass package and NFRC label values.
5. Itemize the opening work. The proposal should cover removal, hidden-damage repairs, flashing, air and water sealing, insulation, trim, disposal and touch-up work.
6. Separate warranty documents. Product and installation-labor coverage are different. Request both in writing, including exclusions, transfer rules, service fees and claim steps.
7. Plan for older homes. For paid work that disturbs painted surfaces in many pre-1978 homes, ask how the firm complies with EPA lead-safe rules.
Use the official ENERGY STAR windows guidance and its explanation of independent energy-performance labels. For older painted homes, review the EPA Renovation, Repair and Painting Program. These sources explain requirements and product performance; they do not rate the installers here.
Window replacement terms worth knowing
Insert or pocket replacement: A new unit is installed within a serviceable existing frame. It can preserve surrounding trim but cannot correct every frame or opening problem.
Full-frame replacement: The existing assembly is removed to expose more of the opening. This can make sense when frames, sills, flashing or opening conditions need correction.
U-factor: A measure related to heat transfer. Lower values generally indicate better insulating performance, but use the applicable label and climate criteria.
Solar heat gain coefficient: A measure of solar heat admitted through the product. The suitable balance depends on climate, orientation and design goals.
Product versus labor warranty: The manufacturer may cover components while the installer separately covers workmanship. Do not assume one document covers both.
Full-frame replacement: The existing assembly is removed to expose more of the opening. This can make sense when frames, sills, flashing or opening conditions need correction.
U-factor: A measure related to heat transfer. Lower values generally indicate better insulating performance, but use the applicable label and climate criteria.
Solar heat gain coefficient: A measure of solar heat admitted through the product. The suitable balance depends on climate, orientation and design goals.
Product versus labor warranty: The manufacturer may cover components while the installer separately covers workmanship. Do not assume one document covers both.
Frequently asked questions
Should I repair the glass or replace the whole window?
Start with the failed component. A cracked pane, failed insulated-glass unit, screen or hardware issue can sometimes be repaired while keeping the frame. Rot, water intrusion, a damaged frame, poor operation throughout the unit or a planned efficiency upgrade may support replacement. Ask a repair specialist and a replacement installer to itemize the alternatives.
What is the difference between insert and full-frame installation?
An insert usually fits inside an existing frame that remains in place. Full-frame work removes the old assembly and exposes more of the opening, allowing inspection and correction of surrounding conditions. The right method depends on the frame, sill, flashing, water history, trim and design goals.
Does an ENERGY STAR label rate the installer?
No. ENERGY STAR and NFRC information describe and verify product performance. They do not score the contractor’s workmanship. Homeowners still need to verify licensing, compare the written installation scope, review references and understand labor-warranty terms.
What should I ask about a pre-1978 Maryland home?
Ask whether the work will disturb painted surfaces and how the firm handles federal lead-safe requirements. The EPA RRP program generally applies to paid renovation work that disturbs paint in many pre-1978 homes and child-occupied facilities. Confirm firm certification and the planned containment and cleanup process.
Can a company pay to move higher on this list?
No. Advertising, sponsored links and guest contributions do not purchase editorial position. Commercial relationships are disclosed, and paid links are marked as sponsored. Businesses may propose a clearly labeled campaign, but publication and claims review remain separate from the editorial list.
Related Maryland home-improvement guides
Continue with our broader Maryland door and window company comparison, the statewide Maryland contractor guide, and the Top 10 Maryland recommendations hub. These pages cover adjacent providers and help you compare the right category before requesting quotes.
For more owner-supplied profiles and contact details, browse Home and Garden businesses in Maryland. Confirm that each business handles the type of window or glass work you need.
For more owner-supplied profiles and contact details, browse Home and Garden businesses in Maryland. Confirm that each business handles the type of window or glass work you need.
Reach Maryland homeowners researching window projects
Window, glass and home-improvement businesses can explore display advertising, clearly labeled sponsored features and editorially reviewed guest-post opportunities. Paid relationships do not guarantee inclusion, claims approval or ranking position, and sponsored links are identified for readers and search engines.
