Nature Meets Resilience: Boston's Pier 4 Green Wall

How does my living wall survive near the ocean with salty, cold, and strong winds?
This was a valid question and challenge of the architect who wished to incorporate a living green wall at Pier 4, in Boston. Therefore, the biggest challenge on this project was how to sustain plant health in the rather harsh environment? Sempergreen managed this challenge with grace, the installation of this beautiful outdoor living wall with approximately 12,000 healthy and happy plants!

Cleaner Air

1 sq ft of living wall filters fine dust, absorbs 2.3 kg CO₂, and produces 1.7 kg oxygen per year.

Cradle to Cradle Certified

SemperGreenwall systems meet the highest standards for quality and sustainability, holding a Bronze-level Cradle to Cradle certification.

Extends facade lifespan

A living wall shields your facade from the sun, rain, wind, and temperature changes, extending its lifespan.

Project design objectives

The objective for the living wall at Pier 4 was multifaceted. With the living wall installed, there was a clear enhancement of the rooftop terrace’s beauty. Introducing the element of nature to the private rooftop terrace not only elevates its aesthetics but also provides the tenants with an exceptionally pleasant space for gathering, relaxation, and socialization. A pronounced goal from the ownership was to enhance biodiversity; the living wall, with its lush plantings and seasonal flowers, significantly boosts the potential for natural habitats on the roof. For reasons of both sustainability and cost efficiency, the owner opted for the Sempergreen system due to its ability to sustain plant life throughout the harsh Boston winter months, thereby reducing the need for extensive plant replacement. The living wall was a pivotal element in achieving the LEED GOLD certification. Living Wall near the ocean.

Living Wall near the ocean

The living wall is located on the rooftop terrace of a 12-story building on one of the seaport piers in Boston, MA. The walls are facing the water and are partly Northeast and partly Northwest facing with limited direct sunlight, especially in the winter months. Obviously, a challenging application especially considering Boston’s winter climate. Appropriate irrigation equipment, site-specific plant species, and careful plant management make it possible to sustain plant health year-round. The wall is approximately 60’ wide and 20’ tall and wraps around an opening towards the building entrance.

The system will be calibrated to a point where it’s wasting none of the irrigation water

Green Wall near the Ocean

The Sempergreen living walls are irrigated with a Sempergreen Plant Care System consisting of a wide variety of sensors to ensure all plants are appropriately and consistently provided with water and nutrients. The plant care system monitors the moisture content in the wall, adjusts irrigation schedules accordingly, and provides plants with microbursts of nutrients through the irrigation water. The system will be calibrated to a point where it’s wasting none of the irrigation water, and the gutter will be there just for emergencies. The proprietary fully automated winter watering system continuously monitors the outdoor temperatures and responds to freezing temperatures with a customized watering schedule every day of the winter, as plants need water throughout winter as well. All sensor data is being communicated with service technicians, and alarm messages will warn the technicians of any inconsistencies, giving them the opportunity to resolve an issue before plants are affected by it.

Obstacles and Challenges

The most significant challenge in this project was maintaining plant health in the rather harsh rooftop environment in Boston, MA. It is fair to state that our first winter was not a success. A frozen pipe led to a cascade of problems. Moreover, the wall faces towards the bay and the ocean, and so during the already cold winter months, a strong and harsh wind, which was underestimated, battered a specific portion of the wall, leaving several plant species struggling.
To prevent the same issue in the future, Sempergreen Services adjusted several elements of the system, updated the plant palette, and improved the maintenance protocols both before and after winter. Additionally, the air-tunnel effect was mitigated by installing a ‘windbreaker’ on the ocean-side patio opening to reduce the harsh winds that would otherwise impact the wall throughout the winter.

The second and all subsequent years were much more successful; in 2021, we barely had to replace any plants, proving to our client and partners that indeed the system could handle such challenging conditions.

Start your green project today

Ready to make a difference? At Sempergreen, we believe in building a greener future, one step at a time. Our innovative solutions are designed to help you decrease your footprint and contribute to a more sustainable world. Join us in replanting the planet!