Case Study
COMMERCIAL WALKABLE SKYLIGHTS
POST HTX — SkyLawn
40 jumbo custom circular walkable and non-walkable SkyFloor® OneXXL System skylights atop a five-acre rooftop public park, plus 62 Series 1000 walkable skylights over the loading dock — engineered to illuminate the spaces below the historic Barbara Jordan Post Office in downtown Houston.
National Excellence in Construction® Eagle
Award — ABC Convention 2022
The POST HTX SkyLawn installation earned installer Griesenbeck Architectural Products a national Excellence in Construction® Eagle Award, presented by Associated Builders and Contractors (ABC) during ABC Convention 2022 in San Antonio, TX on March 16, 2022. The EIC Eagle Award is the construction industry’s leading national recognition, honoring general and specialty contractors for world-class, safe, and innovative construction projects. The award honors every member of the construction team, including the contractor, owner, architect, and engineer.
At a Glance
Client: POST HTX — SkyLawn / Lovett Commercial
Location: Houston, TX
Application: Commercial Jumbo Circular Skylights (Rooftop Park) & Series 1000 Walkable Skylights (Loading Dock)
Completed: 2022
Architect: Powers Brown Architecture · OMA (Partner: Jason Long)
Landscape Architect: Hoerr Schaudt
Installer: Griesenbeck Architectural Products
Glass System: SkyFloor® OneXXL System (Rooftop Park) · SkyFloor® Series 1000 (Loading Dock)
Frame Type: Custom steel perimeter round frame
Anti-Slip Texture: Yorlux
Total Skylights: 102 units — 40 jumbo circular (26 walkable, 14 non-walkable) + 62 Series 1000 walkable loading dock skylights
Skylight Sizes: 3 diameter configurations: 7′, 9′, and 10′ 5¾”
Slope: 18.43° (non-walkable units — design feature)
Installation: Crane installation required for all jumbo circular units
Loading Dock Skylight Frame: SkyFloor® Series 1000 thermally broken framing system
Loading Dock Skylight Glass: Low-iron triple-laminated tempered glass with DG interlayers and an air spacer
Loading Dock Skylight Dimensions: Exposed Frame: 3′ – 11 15/16″ × 3′ – 8 15/16″ · Glass: 3′ – 1 7/8″ × 3′ – 6 7/8″
Loading Dock Skylight Anti-Slip: Yorlux — ANSI A326.3 DCOF Tested (Dry: 0.90 ✔ Pass · Wet: 0.63 ✔ Pass)
Project Highlights
102
Total Skylights
40
Jumbo Circular Units
62
Loading Dock Skylights
5 Acres
Rooftop Park
Executive Summary
Glass Flooring Systems designed and supplied 40 jumbo custom circular SkyFloor® OneXXL System skylights for POST HTX’s SkyLawn — a landmark five-acre rooftop public park built atop the historic Barbara Jordan Post Office in downtown Houston, Texas. Working alongside Powers Brown Architecture, OMA Partner Jason Long, landscape architect Hoerr Schaudt, Griesenbeck Architectural Products, and developer Lovett Commercial, GFS manufactured 26 walkable and 14 non-walkable skylights across three custom circular sizes — ranging from 7 to over 10 feet in diameter — each crane-lifted into position across the rooftop. The skylights bring natural light into the commercial spaces below, while their glowing circular forms become a defining visual feature of the SkyLawn at night, creating a dramatic connection between the park above and the building below. In addition, GFS supplied 62 SkyFloor® Series 1000 walkable skylights installed over the loading dock — bringing natural light into the operational space below while maintaining a consistent skylight language across the full project.
The Challenge
Project Overview
POST HTX is one of the most ambitious adaptive reuse projects in the United States — a 550,000 sq ft mixed-use development transforming the historic Barbara Jordan Post Office into a landmark cultural, hospitality, and event destination. At its crown is the SkyLawn: a five-acre rooftop public park conceived by Powers Brown Architecture and OMA Partner Jason Long as an urban green space offering panoramic views of the Houston skyline.
Key Constraints
- Deliver natural light from the rooftop park into the commercial and event spaces below — across a large, complex roof deck
- Design a skylight system that integrated visually and structurally into the SkyLawn’s curved, organic landscape design — requiring custom circular frames rather than standard rectangular units
- Supply both walkable skylights (for pedestrian traffic zones within the park) and non-walkable skylights (for areas not subject to foot traffic), each engineered to the appropriate performance specification
- Manufacture 40 individual units across three distinct circular diameters — 7′, 9′, and 10′ 5¾” — each made to order for precise fit within the rooftop layout
- Incorporate the non-walkable units’ 18.43° slope as a deliberate design feature — adding visual depth and architectural interest to the skylight forms within the SkyLawn landscape
Why This Mattered
The SkyLawn at POST HTX demanded a skylight solution at a scale and level of customization that no off-the-shelf product could address. Circular skylights of this diameter — in both walkable and non-walkable configurations, across multiple sizes, with custom steel frames — required the full manufacturing capability of Glass Flooring Systems. The project represents one of the largest and most architecturally distinctive commercial skylight commissions in GFS’s portfolio.
Our Solution
System: SkyFloor® OneXXL—Custom Circular
Glass Flooring Systems designed and supplied the SkyFloor® OneXXL System in a fully custom circular configuration—purpose-engineered custom steel perimeter round frames manufactured for each of the three diameter sizes. Both walkable and non-walkable variants were produced to meet the project’s performance requirements.
Frame & Structure
- Custom steel perimeter round frame — purpose-engineered for circular format across three distinct diameters (7′, 9′, 10′ 5¾”)
- Walkable units: flat profile, engineered for pedestrian live loads within the park
- Non-walkable units: 18.43° slope — a purposeful design feature that adds visual depth and dimension to the circular skylight forms as experienced from the park above
- All 40 units manufactured to order with project-specific engineering and fabrication
- Crane installation required and executed for all 40 units across the rooftop construction site
Glass Specification — Walkable Skylights
- Low-iron tempered quad-laminated structural glass panels with SentryGlas® interlayers with an air spacer for thermal performance — meeting ASTM E2751 standard for walkable glazing systems
- Ceramic back-painted perimeter for a crisp, clean appearance — conceals the frame edge and delivers a refined finish from above
Anti-Slip Surface: Yorlux
All walkable glass panels are finished with the Yorlux anti-slip texture — selected for its ANSI A326.3 DCOF slip-resistance performance in a high-traffic public park environment. Yorlux provides the slip resistance required for pedestrian safety in both wet and dry conditions across the open rooftop.
- ANSI A326.3 Dynamic Coefficient of Friction (DCOF) tested — the only nationally recognized anti-slip standard in the U.S.
- Tested using BOT-3000E tribometer — wet and dry conditions
| Texture | Condition | DCOF Result | ANSI A326.3 Status |
|---|---|---|---|
| Yorlux | Dry | 0.90 | ✔ PASS |
| Yorlux | Wet | 0.63 | ✔ PASS |
| Texture | Yorlux |
| Condition | Dry |
| DCOF Result | 0.90 |
| ANSI A326.3 Status | ✔ PASS |
| Texture | Yorlux |
| Condition | Wet |
| DCOF Result | 0.63 |
| ANSI A326.3 Status | ✔ PASS |
Skylight Configuration & Dimensions
40 custom circular skylights across 6 panel configurations — 3 walkable sizes and 3 non-walkable sizes:
| Panel | Qty | Type | Frame Ø | Glass Ø | Walkable | Slope |
|---|---|---|---|---|---|---|
| 1 | 14 | Walkable | 7′ – 0″ | 6′ – 10¾” | ✔ | — |
| 2 | 9 | Walkable | 9′ – 0″ | 8′ – 10¾” | ✔ | — |
| 3 | 3 | Walkable | 10′ – 5¾” | 10′ – 4½” | ✔ | — |
| 4 | 4 | Non-Walk | 7′ – 0″ | 6′ – 10¾” | — | 18.43° |
| 5 | 9 | Non-Walk | 9′ – 0″ | 8′ – 10¾” | — | 18.43° |
| 6 | 1 | Non-Walk | 10′ – 5¾” | 10′ – 4½” | — | 18.43° |
| Total | 40 | 26 Walkable 14 Non-Walkable |
| Panel | 1 |
| Qty | 14 |
| Type | Walkable |
| Frame Ø | 7′ – 0″ |
| Glass Ø | 6′ – 10¾” |
| Walkable | ✔ |
| Slope | — |
| Panel | 2 |
| Qty | 9 |
| Type | Walkable |
| Frame Ø | 9′ – 0″ |
| Glass Ø | 8′ – 10¾” |
| Walkable | ✔ |
| Slope | — |
| Panel | 3 |
| Qty | 3 |
| Type | Walkable |
| Frame Ø | 10′ – 5¾” |
| Glass Ø | 10′ – 4½” |
| Walkable | ✔ |
| Slope | — |
| Panel | 4 |
| Qty | 4 |
| Type | Non-Walk |
| Frame Ø | 7′ – 0″ |
| Glass Ø | 6′ – 10¾” |
| Walkable | — |
| Slope | 18.43° |
| Panel | 5 |
| Qty | 9 |
| Type | Non-Walk |
| Frame Ø | 9′ – 0″ |
| Glass Ø | 8′ – 10¾” |
| Walkable | — |
| Slope | 18.43° |
| Panel | 6 |
| Qty | 1 |
| Type | Non-Walk |
| Frame Ø | 10′ – 5¾” |
| Glass Ø | 10′ – 4½” |
| Walkable | — |
| Slope | 18.43° |
| Total | 40 |
| Walkable | 26 |
| Non-Walkable | 14 |
System 2: SkyFloor® Series 1000 — Loading Dock Skylights
In addition to the 40 jumbo circular skylights atop the SkyLawn, Glass Flooring Systems designed and supplied 62 SkyFloor® Series 1000 walkable skylights installed over the loading dock — bringing natural light into the operational space below while maintaining a consistent skylight language across the full project. Each unit uses our Series 1000 thermally broken framing system, delivering daylight into the garage levels while meeting the project’s energy performance requirements.
- SkyFloor® Series 1000 thermally broken framing system — minimizes cold bridging and condensation while sitting flush with the surrounding roof deck
- 62 units manufactured to identical dimensional specifications for consistent installation across the loading dock roof structure
Glass Specification — Loading Dock Skylights
- Low-iron triple-laminated tempered glass with DG interlayers and an air spacer — engineered for thermal performance and durability in a walkable loading dock application
- Finished with Yorlux anti-slip texture — ANSI A326.3 DCOF tested (Dry: 0.90 ✔ Pass · Wet: 0.63 ✔ Pass)
| System | Qty | Exposed Frame | Glass |
|---|---|---|---|
| Series 1000 | 62 | 3′ – 11 15/16″ × 3′ – 8 15/16″ | 3′ – 1 7/8″ × 3′ – 6 7/8″ |
| System | Series 1000 |
| Qty | 62 |
| Exposed Frame | 3′ – 11 15/16″ × 3′ – 8 15/16″ |
| Glass | 3′ – 1 7/8″ × 3′ – 6 7/8″ |
Construction — crane placement of a jumbo circular SkyFloor® OneXXL skylight unit on the POST HTX rooftop, with the Houston skyline in the background
In-House Engineering, Drafting & Design
Every stage of this installation — from initial structural engineering through final shop drawings — was developed entirely in-house at Glass Flooring Systems. Our engineering team calculated load requirements, glass thicknesses, and frame specifications across all 102 skylights — the 40 jumbo circular units atop the SkyLawn and the 62 Series 1000 units over the garage — while our drafting team produced the detailed fabrication drawings that guided manufacturing for every custom size and configuration. Keeping engineering, drafting, and design under one roof allowed GFS to move quickly between design iterations, resolve coordination issues directly with the project team, and maintain tight tolerances across a project of this scale and complexity — without the delays or miscommunication that come from outsourcing critical technical work to third parties. This integrated approach is part of what allows GFS to take on projects as architecturally ambitious as POST HTX and deliver them with precision from concept to installation.
“It was great to work with you guys on such a monumental project. The installation of the massive skylights helped us earn the National Eagle Excellence in Construction Award from Associated Builders and Contractors for POST HTX.“
— Tanner Spears, President & Co-Owner, Griesenbeck Architectural Products
Results & Impact
What Was Achieved
- 40 jumbo custom circular SkyFloor® OneXXL skylights successfully manufactured and supplied across three diameters — 7′, 9′, and 10′ 5¾” — all installed by crane on the POST HTX rooftop
- Natural daylight delivered through 26 walkable and 14 non-walkable skylights into the commercial and event spaces below the SkyLawn
- At night, the illuminated circular glass panels transform into glowing features within the park landscape — a dramatic visual element that has become one of the defining characteristics of the SkyLawn
- Custom steel round frames engineered to integrate with the SkyLawn’s organic, curved landscape design — a solution no standard rectangular skylight system could achieve
- Yorlux anti-slip texture ensures pedestrian safety across the walkable units in a high-traffic public park environment, in all weather conditions
- All units crane-installed successfully across an active downtown Houston construction site
- 62 SkyFloor® Series 1000 walkable skylights successfully manufactured and supplied for the loading dock, delivering natural light into the operational space below via our Series 1000 thermally broken framing system
- The POST HTX SkyLawn installation earned installer Griesenbeck Architectural Products the national Excellence in Construction® Eagle Award at ABC Convention 2022 — the construction industry’s leading national recognition, honoring every member of the project team including the installer, owner, architect, and engineer
Long-Term Value
POST HTX SkyLawn stands as one of the most significant commercial skylight projects in Glass Flooring Systems’ history — in scale, complexity, and public visibility. The 40-unit circular skylight installation demonstrates GFS’s capability to design, engineer, and manufacture fully custom skylight systems for large-scale commercial and public realm projects, where standard products simply cannot meet the design intent.
Project Team
- Glass System Design & Manufacturer: Glass Flooring Systems
- Architect: Powers Brown Architecture
- Architect: OMA — Partner: Jason Long
- Landscape Architect: Hoerr Schaudt
- Installer: Griesenbeck Architectural Products
About Glass Flooring Systems
Glass Flooring Systems is the world’s leading expert in walkable glass — specializing in structural glass floors, walkable skylights, glass stairs, bridges, decks, and custom architectural glass for luxury residential and commercial projects. Our SkyFloor® OneXXL System, Series 1000 and Series 2000 are available in custom shapes, sizes, and configurations for any and all applications. We set the benchmark for design, quality, safety, and performance in the walkable glass industry.