Construction Listings

The window installation sector in the United States encompasses licensed contractors, specialty glazing firms, fenestration product suppliers, and code compliance inspectors operating under a layered framework of state licensing boards, municipal permitting offices, and national model codes. This directory page documents the structure of construction listings within the window installation vertical — what each entry represents, how records are classified, and where the index does not yet provide complete coverage. The Window Installation Listings resource is organized to serve service seekers, building professionals, and researchers navigating a fragmented contractor marketplace.

How to read an entry

Each listing in this directory represents a discrete business entity operating in the window installation sector. Entries are not ranked by quality, revenue, or customer rating. Classification within the directory follows functional role, not commercial relationship.

A standard entry contains the following structured fields:

1. Business name — Legal or trade name as registered with the relevant state licensing authority.
2. Primary service category — One of four designations: new construction installation, replacement and retrofit, commercial glazing, or specialty fenestration (including skylights, curtain walls, and egress window compliance work).
3. Geographic service area — State or multi-state coverage, recorded at the county level where data permits.
4. Licensing jurisdiction — The state board or municipal authority under which the contractor holds an active license. Fenestration contractors in Florida, for example, operate under the Florida Department of Business and Professional Regulation, which administers the state's certified contractor classifications (Florida DBPR).
5. Code alignment — Whether the listed entity works under the International Residential Code (IRC), International Building Code (IBC), or a state-modified variant.
6. Verification status flag — One of three states: Verified, Unverified, or Lapsed (see Verification Status below).

Entries within the commercial glazing subcategory are further distinguished from residential replacement contractors. Commercial work involving structural glazing systems, unitized curtain walls, or fire-rated assemblies falls under the IBC Chapter 24 fenestration provisions, which impose different performance and testing standards than the IRC Section R308 glazing requirements that govern most residential installations.

What listings include and exclude

Listings within this directory index entities whose primary or significant secondary business activity involves window installation, replacement, or glazing in the construction vertical.

Included:
- Licensed window installation contractors (residential and commercial)
- Glazing subcontractors operating under general contractor oversight
- Fenestration specialty firms offering egress compliance retrofits
- Manufacturers with direct-install programs verified by a state contractor license

Excluded:
- General contractors who perform window installation only incidentally, without a dedicated licensing classification
- Handyman operations not holding a state-issued specialty contractor license for glazing or fenestration
- Product-only suppliers with no installation service arm
- Inspectors and third-party verifiers (covered under a separate inspector classification, not part of the contractor listing set)

The distinction between a licensed glazing contractor and an unlicensed general handyman matters under safety standards: OSHA 29 CFR 1926 Subpart R governs steel erection and glazing in construction contexts, and ANSI Z97.1 sets the safety glazing performance standard referenced by both the IRC and IBC (ANSI Z97.1 overview via GANA). Listings in this directory do not represent endorsement of compliance with those standards — that determination rests with the licensing authority and inspection record.

Verification status

Listing verification is a point-in-time status, not a continuous audit. Three status designations apply across all entries:

• Verified — The listing has been cross-referenced against a named state licensing database within the past 12 months. License number, expiration date, and business name match the official record.
• Unverified — The entry was submitted or sourced from a secondary data feed and has not yet been confirmed against a primary state licensing authority database.
• Lapsed — A previously verified entry where the referenced license has expired, been suspended, or been revoked per the issuing board's public records.

Licensing requirements vary materially across the 50 states. As of the most recent review cycle, 34 states maintain a distinct specialty contractor license category that covers window or glazing installation separate from a general construction license, based on contractor licensing data aggregated by the National Association of State Contractors Licensing Agencies (NASCLA). The remaining states either fold fenestration work under a broader home improvement contractor classification or impose licensing requirements only at the municipal level.

The how-to-use-this-window-installation-resource page provides additional context on how to interpret verification flags when evaluating a specific contractor listing.

Coverage gaps

The directory does not yet provide complete coverage across all geographies and service categories. Known gaps include:

Geographic gaps: Rural counties in the Mountain West and Great Plains regions are underrepresented. States without a centralized, publicly queryable contractor license database — including Wyoming and South Dakota — have lower listing density because primary verification cannot be performed without manual contact with county-level offices.

Category gaps: Curtain wall and structural glazing contractors operating exclusively in the commercial sector are indexed at lower density than residential replacement contractors. This reflects the greater fragmentation of commercial glazing subcontractor data across general contractor relationships rather than direct licensing records.

Specialty work gaps: Contractors who exclusively perform historic preservation window work — subject to Secretary of the Interior's Standards for Rehabilitation (National Park Service, 36 CFR Part 68) — are not yet classified as a distinct subcategory. These entries currently appear under the replacement and retrofit designation.

Permitting record gaps: Entries do not include permit pull history or inspection pass/fail records. Those records are held by municipal building departments and are not aggregated in any national database accessible at scale. The window-installation-directory-purpose-and-scope page describes the data sourcing methodology that governs what information can and cannot be incorporated into entries at the national level.