How To Manage A LEED Charrette - A Real Time Example:
We have completed our LEED charrette for our single-family home that we are designing in Michigan. Thanks to Rich Bloem and Alex Goosen from True North Homes (general contractor) for their assistance in putting the charrette together and facilitating the day.
Wikipedia definition of a Charrette: "While the structure of a charrette varies, depending on the design problem and the individuals in the group, charrettes often take place in multiple sessions in which the group divides into sub-groups. Each sub-group then presents its work to the full group as material for further dialogue. Such charrettes serve as a way of quickly generating a design solution while integrating the aptitudes and interests of a diverse group of people. Compare this term with workshop."
Need some other examples of successful charrette results? Check out these LEED projects:
- Sun & Fun Lifestyle Center In South West Florida
- Cancer Support Community On The Florida Sun Coast
- Single Family, Birch Haven Residence
THE NUTS AND BOLTS OF RUNNING A SUCCESSFUL LEED CHARRETTE:
The first thing one needs to do for a successful charrette is manage the logistics. We met at a great venue called the Pinnacle Center in Hudsonville, Michigan and we were treated with a great conference room full of all the necessary AV equipment that we needed, as well as coffee, breakfast, lunch and breaks throughout the day to make the whole thing very enjoyable. Don't overlook the details and making the participants comfortable during the charrette process.
There are various considerations when executing a productive LEED charrette. Here are a few that we addressed and played a significant roll in the overall outcome.
Number 1: The Players
There were about 20 people who participated in the charrette. Most were there all day. Some came and went. The general contractor, the architect, the landscape architect and many of the subcontractors and material suppliers contributed to the successful day. We discussed all the features of the home and all the systems necessary to construct it in an open forum where everyone contributed. Some had experience in doing green homes and for others this is their first exposure to the process. Several of the participants have been working on preliminary LEED for Homes checklists for the project prior to coming to the charrette.
Number 2: Credits & The LEED Rating System
For this particular home, because of its size, we need to achieve 100 credits in the rating system to obtain our goal of platinum certification. Are preliminary checklists were reflecting scores between 88 and 94 credits. The variation was coming mostly from the HERS score which was anticipated to be anywhere between HERS index of 30 and a HERS index of 44. Learn more about the HERS Index process. Alex Goosen is managing the HERS preliminary rating process, and Jamison Lenz is our LEED Provider from the Green Home Institute, Grand Rapids, Michigan.
Number 3: Teams & Strategies
As a team we went through the entire LEED checklist and looked for synergies between various systems and other design and construction strategies to improve the home's design to a point where he could receive platinum certification. The design itself had already taken into account many passive design elements to make the process easier. The home is already set up with south facing roof to accept PV and/or solar thermal systems to improve the homes energy performance.
Step 4: Trouble Shooting
One of the most interesting discussions of the day was about the homes heating and cooling systems. It was determined that there are more heating load than cooling load, but that it was important that both heating and cooling be provided. The initial basis for the design was a forced air system for both heating and cooling using highly efficient equipment. And there was a need to make the home more energy-efficient to get it from the gold to the platinum level of certification. The air-conditioning and heating sub-contractor provided great input, and practical analysis, as well as a specialist in renewable energy systems (such as PV, solar thermal and geothermal systems) provided his perspective as well. After a great deal of discussion and various systems options, we decided to proceed in evaluating a radiant hydronic floor heating system for the first floor, supplemented with a forced air heating system for the second floor that would also serve as the forced air cooling system for the entire house. We will supplement both systems with solar thermal roof mounted water heating to preheat the water needed for the hydronic floor system and PV solar electric panels supplement the entire system including the forced air system cooling and heating. The PV solar system could be in the range of 5 KW to 10 KW. Solar thermal is yet to be sized but it will provide support to a natural gas fired boiler that will help maintain the water temperature under any conditions. Successfully integrating the systems together should improve our HERS score down to the low 30s or maybe better. Also we will integrate the domestic hot water heating with the radiant floor heating by having those two system share their heat energy which will be an important link to save energy.
WHAT WE LEARNED:
A LEED charrette is a living and breathing process and each one may be different. After we completed this charrette we walked away having learned a few things:
- Michigan has true net metering (you may know that Florida does not, shame on the sunshine state)
- There are many options and heating and cooling systems in Northern climates
- Forced air heating and cooling is most likely the least expensive first cost solution
- Hydronic radiant floor systems provide an incredibly comfortable way to heat a home
The return on investment calculations that the subcontractor will provide will help us make a decision between first cost and lifecycle cost for the system that we end up selecting.
Carlson Studio has been committed to design excellence since 1997. We would like to extend a helping hand whether you are in the research stage, consultation stage, team building stage or other decision making stage. Just hit the button below to request a no cost consultation or any other question you might have.
