5 Things to Know About Bethel's Green Roof

Installed in 2009, Bethel’s green roof offers a variety of benefits, and biology professors are hopeful about the research opportunities it provides.

By Anna Bernin '18, contributing writer

July 09, 2021 | 2:30 p.m.

The Bethel Green Roof is made of 15 different species of sedum, a type of succulent.

The Bethel Green Roof is made of 15 different species of sedum, a type of succulent.

Located mostly out of sight above Brushaber Commons is Bethel’s green roof. The space might be unassuming—but it comes with a variety of benefits, including research opportunities, insulation, and environmental support for the surrounding natural area. “Anything we can do to build sustainably is helping to take care of God’s creation,” says Amy Dykstra, professor of biological sciences.

The green roof was created in 2009 during the construction of Brushaber Commons, which was made possible by donor contributions during Bethel’s last capital campaign. Green roofs offer a sustainable alternative to normal roofing, as they absorb moisture that falls rather than allowing it to run off into storm drains. It’s one of Bethel’s many sustainable practices meant to care for creation. Read on to take a closer look at the green roof and its impact on Bethel’s campus.

1. Creating Bethel’s green roof helped protect the natural areas after building Brushaber Commons.

Bethel is located within the Rice Creek Watershed District, which means construction projects must meet certain requirements in order to protect the natural areas. The university opted to meet these requirements in part through the creation of the green roof, which is 3,780 square feet and contains 15 different species of sedum, a variety of succulent. The green roof replaces some of the natural land and soil that was lost during the construction of Brushaber Commons. It was designed by LiveRoof design and installed by Mickman Brothers. Green roofs are a relatively new concept to the United States, but have been used by other countries for many years. Modern green roofs were developed by Germany in the 1960s and spread to other countries from there.

2. Green roofs offer a variety of “green” benefits.

Green roofs provide insulation from heat, UV radiation, and sound. They lower polluting air particles, promote aesthetics, support biodiversity, and extend the life of the roof by protecting it from ultraviolet rays. They also help avoid storm water runoff. When storm water runs off of a building, it is no longer absorbed by the ground and can lead to flooding and pollution. When the water is absorbed into the ground, it is filtered. However, if it runs off into streets, the pollutants can enter nearby bodies of water.

3. The green roof is pretty low maintenance.

There are two types of green roofs: extensive and intensive. Bethel has an extensive green roof, which means it is low cost and low maintenance. Josh Gerth, manager of grounds, says that maintenance includes weeding, seasonal mowing, fertilizing, irrigation (watering), and replanting. Intensive roofs would also include things like trees and bushes and be much heavier.

The Green Roof can be seen from The Garage in the Loft.

The Green Roof can be seen from the Loft on the fourth floor of Brushaber Commons.

4. The soil used on the roof is specially made.

The green roof contains “engineered soil,” which is a specially made mixture that is different than soil in the ground. It is made of soil and inorganic materials like crushed clay and perlite, which keeps the material lightweight and provides good water drainage. Soil is just one of several layers in a green roof. Other layers include roof deck, protection board, waterproof membrane, insulation, drainage/storage layer, filter fabric, a growing medium, and plants on top.

The succulents are a wide range of colors and species.

With spring arriving, the Green Roof has started to bloom.

5. The green roof provides a variety of research opportunities.

One of the original intentions behind the creation of the green roof was to use it for research. Several types of research can be conducted on the roof. Biologists can peform biodiversity surveys, study how weather affects the roof, or do experiments to see what type of photosynthesis the plants are using. They can also conduct genotype experiments to see if there are hybrid species, or test how the green roof affects the life of the roof. “The act of research is a way to explore and honor the creativity of God,” says Professor of Biological Sciences Teresa DeGolier.

Study biology at Bethel.

Bethel prepares biology graduates who make world-shaping discoveries and understand the relationship between their faith and science. Through experiences in the lab, field, and classroom, you’ll explore the grand diversity of living things and embrace our call to care for all of creation.

Learn More