TreeHouse: Going beyond net-zero

Start-up retailer TreeHouse practices what it preaches. In June 2017, the eco-friendly home improvement retailer broke new ground when it opened a store that will generate more energy than it uses.

Aaron Moulton, the company’s VP of creative and design, and Jenny LaBarge, head of store design and construction, discussed how the nation’s first energy-positive big-box store came together at the SPECS session, “TreeHouse: The Future of Energy is Here.”

Moulton started off the session by giving a brief overview of TreeHouse, which was founded by Jason Ballard in 2011 with a store in Austin, Texas. Specializing in curated products and services that promote healthy and sustainable spaces, the 25,000-sq.-ft. store was designed as a hub for everything tied to smart, thoughtful building. It featured lots of displays, product vignettes and graphics that explain how things work and touted the benefits of non-toxic paint and the like.

But with time, the retailer has shifted to a more experiential, service-oriented model.

“We sell more turnkey projects,” Moulton said. “There is a bigger emphasis on service. We have consultants who will come to your home.”

TreeHouse is focused on smart home upgrades done with eco-responsible products. Its goal is to make the home healthy and sustainable.

In July 2016, TreeHouse broke ground on its second location, at The Hill in Dallas, with the idea of making the building energy-positive. The retailer knew that in order to do so, it would have to, among other things, lower the energy use for the entire building.

“We did a review of the annual energy use of our Austin store, using it to model the expected energy use of the new location,” Moulton said.

The retailer (with Lake|Flato Architects) quantified how much electricity could be saved through the use of daylight, LED lighting and heat load reduction tactics.

The store’s architecture is crucial to its energy efficiency. It boasts saw-tooth roofs that are positioned in such a way to maximize the effectiveness of its giant, ultra high-efficiency solar rooftop array, which comprises 530 panels. (This feature solved the need for extra space for solar panels.)

“The store was designed so well from the beginning,” LaBarge said. “We didn’t need as many solar panels as we initially thought, which resulted in a quicker payback.” (The panels are from SunPower and are expected to last 25-to-30 years.)

Sunlight

North-facing clerestory windows allow for indirect sunlight to effectively illuminate the interior without the impact of direct heat. This allows for a cooler baseline temperature in the store and a minimized use of electricity. The standing-seam metal roof collects rainwater and reflects heat.

High-bay LEDs supply overall light. Focused display light is used when needed. The lighting is sensor operated.

“The temperature on the sales floor ranges from 68 degrees to 70 degrees,” LaBarge said. A big fan array helps keep the store comfortable and minimizes the use of the air conditioning.

A Tesla Powerpack (a rechargeable battery storage system for utility and commercial applications) is located at the center of the store. It stores the power produced by the rooftop solar array, deploying it for evening use and allowing the building to return excess renewable energy to the city’s grid.

On-site solar energy and Tesla battery storage systems were then designed to support the new store’s needs.

The new TreeHouse didn’t perform out of the gate to what was expected. Two months after opening, it was only generating four hours of positive energy a day.

“It took us about six months to get up to speed,” Moulton said.

In other features, the store boasts a living wall on the left past the entrance. It does double duty, reflecting the company’s commitment to sustainable living and also serving as an active air purification system.

As for the lessons learned from the Dallas store, Moulton said there are a few:

• Plan for solar for each location;


• Have abundant daylight; and


• Use fans and LED lighting in every store (“that’s a given,” he added).

“We also learned to have an intense vetting system for electrical systems going forward,” Moulton said.

In early 2018, TreeHouse opened its third location, in Plano, Texas. Going forward, the retailer expects to open four stores in 2019.