Our Nevins & Pacific Street homes are pushing towards the finish line. The old brick façade of the building has been fully restored as planned, using a combination of the old and new bricks. Seeing the finished façade reminds me of our original goals; we simply wanted to build the best homes possible using what the site and nature provided as a starting point, while developing a new model for building practice. Every choice made along the way was towards building homes designed to bring comfort and pleasure to those who would live there, in balance with the need to show consideration for the world’s resources. These homes will be healthy, efficient and comfortable for the people that live there and for the community and world they live in.

Reducing the Carbon Footprint:
“A typical American Single family home is responsible for more than 11 metric tons of carbon dioxide emissions every year through its energy use.” -The New York Times, 4/20/08

The homes at 93 Nevins Street and 453 Pacific Street mitigate the carbon footprint in ways big and small. Following are typical problems found in homes today, along with ways in which ours are different:

Home Heating and Air conditioning:
- Typical heating and air conditioning systems produce well over half of the carbon emissions of a home, or 6.7 metric tons. The typical home is free-standing.

Our homes – as many in the urban environment – present an efficiency advantage in that they are generously-sized 2,800sf residences with three bedrooms, but are situated side by side. Thus, they share common walls with each other and with neighboring buildings, thereby exposing less of the building to the elements.

- According to AHRAE 90.1, a national energy standard developed by the American Society of Heating, Refrigerating and Air-Conditioning Engineers, the exterior walls of a typical building in our climate zone must achieve an insulation rating of R13. Existing buildings often are far less insulated.

Our exterior walls will achieve an average rating of R27. We paid careful attention to the building envelope, making sure to insulate the existing shared walls and create a high performance shell for the new walls. The new wall system starts with limestone masonry blocks, then a cavity airspace, then a hard insulation, then Densglass sheathing, and finally Nu-Wool blown-in insulation on the inside.

In our climate zone, typical building windows under ASHRAE 90.1 have a U-factor of 0.67 (U-factor measure the rate of heat loss). For our homes, we installed windows with thermal breaks and insulated double panes, with a U-factor of 0.32 – or more than double that required by code.

The above measures ensure that our systems do not need to operate at full capacity to heat and cool. We also used zones to further control usage.

- A typical home uses three different pieces of equipment to create heat, air conditioning, and domestic hot water.

We use one machine – a gas-fired heat pump, in combination with a solar hot water system, to meet all needs for heating, cooling and domestic hot water.

- A typical heating system heats water to 120 degrees, then delivers it through radiator systems which distribute heat unevenly, and use valuable floor and wall space.

We designed our system around the efficient delivery of the Warmboard radiant subfloor system. This system evenly distributes heat using only 88 degree water to heat the space quickly and efficiently.

On the cooling side, a typical home’s air conditioning unit uses ozone-depleting chemicals to create cool air; it also uses electric power. Our homes are outfitted with Robur gas-fired absorption heat pump units which use ammonia, a non-ozone-depleting chemical. In the urban environment, electricity is costly and is susceptible to great transmission loss – especially in the summer months, when heavy loads lead to blackouts and higher pricing, and when the oldest and dirtiest electrical power plants are brought on line. In contrast, the Robur units burn a small amount of gas on site, which is far more efficient and will cost the owner far less.

For more than seven months of the year, solar heating will meet most of the domestic hot water needs, and will contribute a portion of both the heat and domestic hot water for the rest of the year.

Other Live Loads
- Typically, the balance of a home’s electric usage adds up to another 4.3 metric tons, used for things such as appliances, televisions, computers, and microwaves.

The Nevins and Pacific Street homes use only Energy Star appliances, chosen for their efficiency in terms of overall electric and water usage, and cleaning efficiency. We also will install 2.2 kilowatt per home of solar PV panels, which will reduce the draw on the grid, as well as the overall carbon footprint of these homes.

Materials: Building Practice and Reducing, Reusing & Durability
- In a typical home, the building practice is wasteful.

With our homes, we were determined to develop and follow a path of less waste.
That began with saving the façade, the existing two-story structure. Had we torn it down, it would have all had to be sent to landfill, and then replaced with loads of new material. We carefully removed the bricks and rebuilt what was necessary. We used as many of the old bricks we could, and mixed in both new and other recycled material.

Supplied by Green Depot, our construction materials were chosen for their recycled content, local manufacture, and overall durability.

Our design elements were all chosen for their low carbon footprint, efficiency in manufacture, beauty, and local manufacture –to reduce shipping as much as possible. Our plumbing fixtures were chosen to reduce water usage, without compromising on quality or performance.

Green Depot used their biodiesel fleet to deliver materials to the site.

We separated and recycled all of our material waste and packaging, and carefully tracked it to ensure that we reduced waste and material sent to landfill.

Durability
- Green building is better building.

Durability is the most important sustainability issue, as it brings the most value to a home over time. Because of the level of attention to performance over time, our homes will maintain their value for generations. They will also cost less to maintain. The insulation has a lifetime warranty. The roofing has a twenty year guarantee. Because our heating and cooling plant needs to work less, these systems will last longer.

Health and Wellbeing
Our buildings will be the first to be certified by the American Lung Association Health House program.

- A typical home is constructed using many building products that affect the overall indoor air quality.

Our homes filter the air from the outside, and allow for fresh air intake to all rooms. The building serves as a lung - the filtration cleans the incoming air, and exhausted air is actually cleaner than incoming air.

We use materials with no- or low-VOC (volatile organic compounds) content, thereby reducing off-gassing and toxins within the home. We use mold-resistant drywall, sheathing and insulation. We allow for the escape of vapors to control moisture build up. By having such a high performance building shell and dense insulation, as well as interior sound insulation between neighbors, we are able to create a more peaceful and healthful interior environment.

The urban environment is more efficient, but it is also more stressful. We have done everything possible to make our homes sanctuaries amidst the urban bustle. We designed the living spaces around the green views of Boerum Hill Brooklyn. We added grapevines which shade the windows in the summer, yet allow the sun through in the winter. We will plant trees with water-conserving tree pits around the perimeter.

Green is Beautiful
Working with our designers and Green Depot, we have achieved a extremely high level of design, while taking into consideration how these homes fit into the world at large.

Architect Tony Daniels is currently working to estimate the carbon footprint for the Nevins and Pacific Street homes, and we will publish his results here when they are available. Though we do not yet have an exact number, we recognize that all efforts to reduce carbon are important to the sustainability of the planet, and we know that if our projections are correct, these home will be economically sustainable well into the next generations.