Green Building Details
Our goal in constructing our new home was to make it the “greenest church in Iowa” as an expression of our commitment to the earth and as a model for others to follow.
In following green building principles during the design and construction of our new church, we weighed a number of considerations. The following piece, written by one of our partners from Neumann Monson Architects, describes our goals and some of the choices we made along the way.
By Matt Krieger, AIA, LEED AP BDC
Neumann Monson Architects
Unitarian Universalists believe in justice, equity, and a respect for the connections of all existence of which we are all a part. When they said they were looking to build a new facility, they were looking for a way to secure their future and to do so in a way that respected the Earth.
And throughout the planning process they have always emphasized that it shouldn’t just look green, it should actually be green. It’s about true performance.
This new facility has been designed using biophilic principles – connecting the building and its occupants with nature. Natural daylight and views from the spaces within set the congregation directly in the wooded site. Through a life-cycle analysis, materials have been selected for their low environmental and human health impacts, fostering the idea that buildings are made for people and they should be healthy for them. Three bio retention cells around the building and parking lot will control and filter stormwater runoff to prevent flash flooding and erosion onto neighboring properties and the creek beyond.
On top of all this, the congregation had a vision to provide their own power produced from renewable sources right here on this beautiful site. The goal is to be net zero – to produce as much power as they use on an annual basis. The church plans to install a solar PV array to reach this goal, and to make sure they do so, they will be seeking a Net Zero Energy Building Certification under the Living Building Challenge program.
Biophilia is a design concept that connects buildings and occupants with nature – original book by E.O. Wilson. There are lots of ways to do this but at its essence, biophilia has shown through research to have positive physiological impacts to the human body. Less stress, more energy and improved performance by occupants, and increased comfort. Terrapin Bright Green has a really good summary of the strategies and links to resources.
There are about 14 overall biophilic strategies that can be incorporated into the design, and for this project we utilized visual connection with nature (direct views to woodland and sky), dynamic and diffuse light (glass allows lighting from multiple directions, exterior sunshade and light through trees creates dappled patterns), connection with natural systems (direct access to woodland), biomorphic forms and patterns (carpet pattern, use of natural colors), material connection with nature (use of natural materials), complexity and order (rhythm of the structural bays and the curve).
A life-cycle analysis evaluates the complete life cycle of a material (raw material and harvest, production, transportation, construction, use and maintenance, and end of life) against many environmental impacts including global warming potential, ozone depletion, acidification, smog development, human health impacts, eutrophication, resource depletion, and ecotoxicity.
- We evaluated many of the cladding and interior materials with the LCA and against the budget to determine the best options
- Cedar exterior cladding and interior ceiling is made of wood harvested in the U.S. and has stored carbon dioxide within the material – much better than masonry, metals, etc. The natural finishing and weathering will reduce maintenance costs and environmental impact and be durable for long period of time.
- Glass selected for energy efficiency and reduced quantities across the entire building envelope to increase thermal performance.
- Roof insulation better than code required minimums for better thermal performance
- ‘Healthy’ materials selected for interiors – low VOC’s (volatile organic compounds) for carpet, adhesives, sealants, and paint and coatings.
- Recycled glass countertops (two different kinds) were selected for durability over time and for their low impact raw material.
- Polished concrete floor – this is more about reducing the need for multiple layers of materials thus reducing the overall impact. It’s also durable and helps with solar passive and energy efficiency strategies
- Energy efficient design strategies include passive strategies like passive solar in large spaces, high performance glass and framing systems, and increased insulation.
- Geothermal ground-source heat pump system is more energy efficient (uses radiant concepts)
- Use of radiant heating in floor slab is low energy system
- Energy recovery units for ventilation system.
- LED lighting throughout
- Energy Star appliances and energy recovery steam dishwasher unit
- On-site renewable energy production through solar array
- Reduce parking capacity – total parking lot size reduce due to use of shared parking nearby
- Building located to preserve as much existing vegetation as possible
- Three bio retention cells manage stormwater runoff and toxicity
- Native grasses to be planted
- Bicycle trail extended to connect to building, bike racks installed, and shower provided inside Equity
- Accessible design incorporated with increased quantity of handicap parking
- Accessible entries
- Parking drop-off near entry and no curbs throughout
- Floor slab designed to eliminate flooring transitions from carpet and tile to concrete
- No permanent seating at interior spaces for flexibility
- Gender neutral restroom
- Green Building Certification: Multiple certifications evaluated, going with Net Zero Energy Building Certification offered through the Living Building Challenge that will measure a year’s worth of energy performance.