At SK Collaborative, my green building certification and consulting business, we certify projects through LEED, National Green Building Standard, EarthCraft, Green Globes, and Enterprise Green Communities. Our work is primarily multifamily — both affordable housing and market-rate projects — as well as market-rate single-family homes. Most of our projects are standard low- and mid-rise apartment buildings of the type that are popping up everywhere.
Although we are always looking for exciting, ground-breaking projects to work on, financial constraints keep most clients from pushing boundaries too far. I don’t mean to imply that the buildings aren’t well built and high-performance — they certainly are, especially as compared to standard construction. It’s just that our opportunity to work on truly cutting-edge high performance projects are few and far between.
The Low-Income Housing Tax Credit program encourages green features
Interestingly, we find that affordable housing projects incorporate some of the best construction, primarily due to requirements that developers must meet to obtain the Low Income Housing Tax Credits (LIHTC) that help fund their projects. In many states, including Georgia, the LIHTC heavily incentivizes green building certification, so much so that every project funded through this program for the past several years has achieved green certification.
Some of the more interesting projects we have worked on recently include the second LEED home in Mexico, and my personal home, which I have written about extensively (and from which I learned that the best way to work on truly high-performance projects is to develop them yourself).
However, not being professional developers, we rely on our clients to bring us projects to work on, and are dependent on them to make sustainability decisions.
Building in the Caribbean
This all brings me to a recent project in St. Thomas. Magens Junction is a 48-unit affordable housing project using LIHTC funding. To secure the tax credits, this project must be green certified, and we were contacted to assist in the process.
This project was an appealing one to work on for many reasons. Beyond the most obvious one — the opportunity for a couple of trips to the Virgin Islands for site inspections — the construction techniques are all new to me and the project is incorporating several interesting sustainable practices.
The project consists of two poured concrete six-story buildings, connected with open walkways. There is no insulation in the walls, nor is there any heating or cooling in the units — not something we are used to seeing in new construction. Although hotels and stores in St. Thomas are often air-conditioned, many homes on the island rely on passive cooling through cross ventilation and ceiling fans. Expensive and unreliable power makes this a smart decision, particularly for low-income residents.
We are certifying the project under the 2015 NGBS which has a tropical climate exemption for insulation and HVAC, based in part on a similar provision in the 2015 IECC. This option makes sense for projects such as this, which otherwise would not meet standard insulation and HVAC efficiency requirements.
In addition to facing challenges with electric service, the project must address the fact that fresh water is a rare commodity in the area. Many buildings collect rainwater and reclaim greywater for reuse, and this project is no exception. The basement of each building contains two large cisterns, one each for rainwater and greywater. The greywater is treated and used for toilets and irrigation, and the rainwater, combined with well water that is purified through reverse osmosis, is stored for potable use in the units.
The project is off-grid
The most interesting elements of the project concern electricity and hot water. The developer chose to keep this project completely off-grid to avoid problems from frequent power interruptions. This will be accomplished by a combination of propane-powered turbines and photovoltaic (PV) panels. In addition to electricity, the turbines produce hot water (from waste heat) which will be used to provide domestic hot water to the building.
The project is essentially both a building and a water and power utility company. Each unit is separately metered for electricity and both hot and cold water, allowing for each unit to be billed for their actual power and water use.
I have already visited the site for an initial inspection (a tough job, but someone has to do it) and we will be back for a final inspection when the project is complete to complete the certification process. I’m looking forward to seeing the project complete and learning how it works as possibly the first off-grid affordable housing project in the U.S.