From the Field: Backlit Onyx Feature Wall Installation in Ottawa

Last winter, the GPI Design team was commissioned to engineer one very unique feature wall in the lobby of 150 Elgin Street in Ottawa, Ontario. Within the main lobby of this 21-story office complex, the designers at NEUF Architect(e)s and ownership at Morguard Investments imagined a glowing onyx wall to dazzle visitors and tenants. Intended to bring an organic texture to the crisp white gallery-like space, the surface possibilities for the onyx wall were left open to the imagination.

Taken by the concept and encouraged with the general contractor’s (PCL Constructors) foresight to plan the feature into the schedule well in advance, GPI Design began working to deliver the backlit onyx wall. Working with an intense obsession for detail and a critical eye on constant refinement, we crept towards the November 2013 completion date.

Now, after much coordination and anticipation, November 2013 is finally here, and we are on site! Here is a condensed look at our development of the feature wall over the last 11 months.

Phase 1: Concept

The designers’ rendering is shared with GPI, establishing the aesthetic vision for the feature wall and its connection to the surrounding space.

150 Elgin Lobby Backlit Onyx Rendering

Phase 2: Engineering

The GPI team begins structural engineering. Prior to final submission, the architect and contractor visit the GPI studio for shop drawing and mock-up reviews where slight adjustments are made. Shops drawings are revised per the review and submitted to the client for approval.

Engineering Section Detail Backlit Onyx Wall

Phase 3: Stone Selection

GPI’s director, Thomas Lawrence, accompanies our geologists on a sourcing trip where they discover the rare Petri Onyx. Meeting all the design criteria for color and patterning, this rare stone variety is procured.

Petri Brown Honey Onyx Pattern Slab

Phase 4: Pre-Production

The GPI Design team performs extensive studies on the layout possibilities of the onyx, and receives feedback from the client on the visual intent; the client selects concept B. Based on this selection, GPI compiles complex production diagrams precisely indicating how the stone will be mapped and cut to execute the desired patterning.

Onyx Bookmatch Pattern Movement Diagrams GPI

Phase 5: Production

After tweaking the lighting cavity and finessing the attachment details, all components of the feature wall are sent to production. This includes: the substructure (custom metal rails, custom powder coat for joints, all fasteners), the onyx itself, LED panels with custom color temperature, wiring, and hand built lighting controllers.

Backlit Honey Onyx Color Swatches

Phase 6: Site Prep + Shipping

All existing site conditions are coordinated to reflect GPI shop drawings and adjusted to fit the feature wall system. Components are shipped to converge on site just prior to our crew’s arrival.

Substructure Wall Construction Backlit Onyx

Phase 7: Installation

This is our current stage in the process – the rewarding phase where all the months of hard work finally come together. Our installation team members have been involved in every aspect of the engineering process, giving them an intimate understanding of the nuances of this system. And with tight 1/32” tolerances, there are many long working days for this dedicated crew.

Backlit Onyx Feature Wall Installation Art

Phase 8: Lighting Adjustments + Programming (to come in the near future)

After all onyx panels are installed, GPI’s lighting technician will analyze each panel individually, then as it relates to the composition as a whole. Based on panel size and stone translucency, our tech will address and adjust the brightness of each individual panel to harmonize illumination along entire wall.

For ease of control, the client opted to have GPI create a central theatrical lighting controller system, synchronizing the behavior of each of our 4 Infuse™ Power Supply/Dimming Units powering the wall. Once programmed, this will offer predetermined scene selections which can be accessed and implemented directly from an iPhone or iPad app.


THANK YOU to the project teams at NEUF Architect(e)s, Morguard Investments, PCL Constructors, and J2 Construction Management for your upbeat spirits and continual willingness to embrace the natural (and beautiful!) potential of onyx.

Stay tuned to our Facebook page as we post more photographs of the installation wrapping up and completing the final touches.