SI Windows
SI Windows is a privately held Tucson, Arizona-based manufacturer of aluminum and vinyl windows and patio doors, serving residential homeowners and multi-family contractors across the Southwest United States through regional dealer distributors.
- Company typePrivate
- Founded1976
- HeadquartersTucson, United States
- Headcount11–50
- GTM typeB2B and B2C
- OfferingHardware or Manufacturing
What SI Windows does
SI Windows is a privately held, vertically integrated manufacturer of residential windows and patio doors, founded in 1976 and headquartered in Tucson, Arizona. The company fabricates products in two material platforms — aluminum and vinyl — organized into multiple series including the MF2 Aluminum Window and Patio Door, the 4000 Series and 5000 Series Vinyl Windows, the 5400 Series Vinyl Patio Door, and a 2000 Series Vinyl Window. All products incorporate double-paned glass with Warm Edge Spacer technology and High Performance Low-E Glass; the 5000 Series additionally uses a Duraseal spacer. Frames are offered in multiple installation configurations (Nail On, NuWall, Masonry, and Flush Fin retrofit), and the company manufactures both standard sizes and made-to-order custom shapes, arches, and grid patterns. Selected lines carry a Limited Lifetime Warranty.
The company serves two end-customer segments: residential homeowners needing replacement windows, and contractors/builders executing single-family and multi-family construction projects. Revenue is generated through one-time product sales via a two-tier regional dealer network anchored by The Window Depot (6 locations across Tucson AZ, Phoenix AZ, Albuquerque NM, El Paso TX, and National City CA) and Contractors Warehouse (14 locations across California). SI Windows also accepts direct inquiries for multi-family project bidding, indicating an explicit bid to capture larger B2B project work alongside its homeowner-replacement base. Pricing is not publicly disclosed; quotes are obtained through sales contact.
SI Windows operates with a headcount of 11-50 employees from a single Tucson manufacturing and office facility at 4940 South Alvernon, and shows no disclosed funding history, M&A activity, institutional investors, or parent/subsidiary relationships. Marketing presence is limited to a product-information website with a dealer locator; there is no app, no public API, and no disclosed AI/ML or digital-product capabilities. The business model is therefore a conventional regional building-products manufacturer: fabricate standardized and custom residential fenestration in Tucson, distribute through authorized dealers across the Southwest, and capture incremental volume through direct multi-family contractor sales.
SI Windows firmographics
Firmographics- Name
- SI Windows
- Legal name
- SI Windows
- Website
- https://siwindows.com
- Company type
- Private
- Founded year
- 1976
- Operating status
- Operating
- Headcount range
- 11–50 employees
- Short description
- SI Windows is a privately held Tucson, Arizona-based manufacturer of aluminum and vinyl windows and patio doors, serving residential homeowners and multi-family contractors across the Southwest United States through regional dealer distributors.
- Ownership category
- akta.pro rank
SI Windows industry classification
Industry- Product category
- Window and Door Manufacturing
- NAICS
- Metal Window and Door Manufacturing (332321)
- SIC
- Metal Doors, Sash, Frames, Moldings & Trim (3442)
- akta.pro primary industry
- Windows (IMADAIAC)
- akta.pro secondary industries
- Custom Window & Door Fabrication & Replacement (HSAPAJAI), Window Replacement (Residential) (HSAPAJAA), Doors, Windows & Millwork Retail (Interior/Exterior Doors, Windows, Moulding) (CRAIAEAI)
Keywords
Where SI Windows is headquartered
LocationHeadquarters
- HQ city
- Tucson
- HQ country
- United States
- HQ region
- North America
Offices2 records
Markets served
SI Windows business model
Business model- GTM type
- B2B and B2C
- Offering type
- Hardware or Manufacturing
- Cost components
- Personnel, Supply Chain, Operations, Infrastructure, Marketing or Sales
Revenue model
- Windows and Patio Doors Sales: One-time product sales of aluminum and vinyl windows and patio doors to residential customers, contractors, and multi-family project builders. Revenue generated through direct sales to dealers and distributors.
Go-to-market motion1 record
Distribution channels2 records
Marketing channels1 record
SI Windows product offering
Product offeringCore offering
SI Windows manufactures and supplies premium aluminum and vinyl windows and patio doors for residential and multi-family construction projects. The company produces a full product line including the MF2 Aluminum Window and Patio Door, 4000 and 5000 Series Vinyl Windows, and 5400 Series Vinyl Patio Door, with standard sizes and custom shapes available. Products are sold through authorized dealers across the Southwest United States and directly to multi-family project contractors.
Product overview
SI Windows is a premium quality window and patio door manufacturer serving the residential market across the United States, specializing in both Aluminum and Vinyl product lines. The company operates a unified product portfolio organized into two main material categories: Aluminum products (MF2 Aluminum Window and MF2 Aluminum Patio Door) and Vinyl products (4000 Series Vinyl Window, 5000 Series Vinyl Window, and 5400 Series Vinyl Patio Door). All products are available in standard sizes with customization options including grids, arches, and special shapes. The company positions itself as serving both individual homeowners and multi-family project contractors, with products designed for residential applications including single-family homes and multi-family developments throughout the Southwest and broader U.S. market.
Differentiator
Problem solved
Functional benefit
Products and services
- MF2 Aluminum Patio Door Aluminum patio door featuring double paned tempered glass with Warm Edge Spacer, available in single and tandem rollers, horizontal slider configurations (XO, OX), and key lock option. Designed for residential applications.
- MF2 Aluminum Window Aluminum window with 2 5/16" aluminum frame available in NuWall 1 3/8" set back and Masonry applications. Features double paned glass with Warm Edge Spacer, high performance Low-E Glass, brass rollers, block and tackle balancer system, and positive action cam lock. Available in horizontal sliders (XO, OX, XOX), single hung, picture windows, and special shapes in Bronze and White with Limited Lifetime Warranty.
- 4000 Series Vinyl Window Vinyl window with 2 3/4" frame available in Nail On 1" set back, NuWall 1 3/8" set back, and Masonry configurations. Features acetal rollers, drop in wet glazed design, available in white and almond. Offers horizontal sliders (XO, OX, XOX), single hung, picture window, and special shapes with flat and sculptured grid options. Backed by Limited Lifetime Warranty.
- 5000 Series Vinyl Window Premium vinyl window with 3" frame offering multiple installation options including Nail On, NuWall, Masonry, and Flush Fin for retrofit applications. Features double paned glass with Duraseal spacer and Warm Edge Spacer technology. Available in horizontal sliders (XO, OX, XOX), single hung, picture window, and special shapes.
- 5400 Series Vinyl Patio Door Vinyl patio door featuring tandem brass rollers for smooth operation and mortise lock for enhanced security. Available in multiple horizontal slider configurations (XO, OOX, XOO) to accommodate various opening requirements.
- 2000 Series Vinyl Window Vinyl window series referenced in the SI Windows product portfolio, included in the company's full line of vinyl windows for residential applications.
Companies that use SI Windows
Customer profileSegments2 records
Ideal customer profiles2 records
SI Windows technology and API
TechnologyTechnology focussed No
API detail
- Has API
- No
- API docs
- API detail
Core technology
AI maturity
App detail
Feature7 records
SI Windows partnerships and signals
Strategic signalScale indicators2 records
Recent moves5 records
Expansion highlights4 records
SI Windows competitors and assessment
Company assessmentEmerging players
- Window World: Window World is a national franchise-based window replacement retailer that sources from manufacturers and competes with SI Windows' dealers (e.g., The Window Depot) for Southwest replacement customers.
- Quaker Windows & Doors: Quaker manufactures windows and doors with strong multi-family and light commercial exposure, directly comparable to SI Windows' emphasis on contractor and multi-family project work.
Broad incumbents
- Ply Gem Windows: Ply Gem is a large national building products manufacturer with a broad vinyl and aluminum window portfolio, serving builders and dealers in the same markets as SI Windows.
- Atrium Windows and Doors: Atrium is a national vinyl window manufacturer focused on replacement and new construction, overlapping with SI Windows' vinyl product lines and dealer-driven GTM.
- Jeld-Wen Windows & Doors: Jeld-Wen is a large national manufacturer of windows and doors (including vinyl and aluminum lines) that competes with SI Windows in residential and multi-family markets across the Southwest.
- Pella Windows & Doors: Pella is a national, multi-material window and door manufacturer with deep builder relationships and broad dealer coverage, representing the larger incumbent competition that regional players like SI Windows face.
- Andersen Windows & Doors: Andersen is the largest U.S. window and door manufacturer with a broad product portfolio (wood, vinyl, composite, aluminum-clad), competing against SI Windows in both residential replacement and multi-family builder segments.
Direct peers
- Simonton Windows: Simonton manufactures vinyl windows and patio doors for replacement and new construction, serving a similar residential customer base and competing in the same dealer-distribution channel as SI Windows.
- Milgard Windows & Doors (MI Windows): Milgard is a major Western U.S. window and patio door manufacturer with overlapping vinyl and aluminum lines; it competes with SI Windows for the same Southwest builder and dealer channels, particularly in California and Arizona.
- Anlin Windows & Doors: Anlin is a regional vinyl and aluminum window manufacturer based in California, directly comparable to SI Windows in product mix, regional dealer focus, and customer base (homeowners + multi-family contractors in the Southwest U.S.).
Market position
Strengths5 records
Weaknesses5 records
Competitive moat3 records
Key risks5 records
Key highlights6 records
Customer concentration
SI Windows social profiles
Digital presenceSI Windows financial estimates
Financial estimateRevenue estimate
Valuation estimate
SI Windows leadership team
Management profileNumber of profiles
SI Windows funding detail
Funding detailFunding overview
Funding rounds
Investors
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
SI Windows M&A and investment
M&A and investmentM&A
Investments
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about SI Windows
What does SI Windows do?
SI Windows manufactures and supplies premium aluminum and vinyl windows and patio doors for residential and multi-family construction projects. The company produces a full product line including the MF2 Aluminum Window and Patio Door, 4000 and 5000 Series Vinyl Windows, and 5400 Series Vinyl Patio Door, with standard sizes and custom shapes available. Products are sold through authorized dealers across the Southwest United States and directly to multi-family project contractors.
Is SI Windows a public or private company?
SI Windows is a private company. It is classified as founder individual operated bootstrapped and is currently operating.
When was SI Windows founded?
SI Windows was founded in 1976. It employs 11 to 50 people.
Where is SI Windows based?
SI Windows is headquartered in Tucson, United States, in the North America region.
How does SI Windows make money?
One revenue line is on record: windows and Patio Doors Sales.
Who are SI Windows's main competitors?
Emerging players on record are Window World and Quaker Windows & Doors. Broad incumbents are Ply Gem Windows, Atrium Windows and Doors, Jeld-Wen Windows & Doors, Pella Windows & Doors and Andersen Windows & Doors. Direct peers are Simonton Windows, Milgard Windows & Doors (MI Windows) and Anlin Windows & Doors.
Does SI Windows have an API?
No public API is recorded for SI Windows.
What industry is SI Windows in?
SI Windows's product category is Window and Door Manufacturing. Its primary akta.pro industry code is IMADAIAC, Windows, with a secondary code of HSAPAJAI, Custom Window & Door Fabrication & Replacement. Its NAICS code is 332321 and its SIC code is 3442.