Like a Phoenix rising from ashes, New Orleans is going through a similar transformation. It is a city that is beginning to rise from the ruins left behind by Hurricane Katrina while fighting off another environmental disaster. The hope is that the new New Orleans will be stronger, greener, and more equitable while still retaining and honoring its rich culture and history.
Historical Context
This home is symbolic of this hope. The front of the home--with its deep, wrap-around porch, narrow facade, large windows, and gable roof--fits in with its Broadmoor neighbors while paying homage to the architectural history of shotgun houses in New Orleans. The back of the house rises up to enclose the small second floor in a modern interpretation of the historic camelback style.
Affordable
The Phoenix house was carefully designed and tweaked with the tight budget in mind. The cost estimate attached shows the construction cost of the house to be estimated at $97,774. While this is only a couple of thousand dollars below the budget, there are a couple of reasons costs were not pushed lower. First, quality and sustainability were maximized for this cost. A couple of examples include wood floors throughout, a large number of windows most of which are operable and very efficient mechanical equipment. Second, the cost estimate produced for this house is more detailed and comprehensive than the cost template provided. Furthermore costs can be verified because sources for all line-item costs are identified.
Sustainable
The house is designed to be as green as the budget will allow. The project is on target to get 108.5 points or 28.5 points above the minimum threshold for Platinum Certification in the LEED for Homes rating system. An additional 6.5 credits listed in the ‘maybe’ column are not included in the 108 points, but are possible. Strategies employed include high-density insulation, high-performing windows and mechanical equipment, Energy Star appliances, and the balanced design of ample fenestration for daylight throughout the house and features that control heat gain and glare including shutters, deep overhangs, and careful orientation of openings despite the north-south axis of the house.
The off-axis angle of the rear and upper portion of the house not only accommodates programmatic requirements, but also allows more windows that face north and south. Where windows are located on the long walls of the house they are mostly concentrated on the east wall since morning solar heat gain is not as detrimental to indoor comfort as afternoon heat gain.
The energy use of the house was modeled with Green Building Studio, a web-based program that calculates a building’s estimated annual energy use and cost through the use of the project’s BIM model plus additional inputs provided by the user (e.g. insulation type, mechanical equipment, etc.). With feedback from earlier energy model runs, improvements were made that ultimately led to a final energy model report (attached) that estimated energy use that is 51.0% below standard (per Energy Star Target Finder) and an average total annual energy cost of $443 (or approximately $37 a month).
“Less is more”
When it comes to both sustainability and affordability often Mies van der Rohe’s adage “less is more” holds true. The Phoenix house is to be framed with advanced framing techniques or Optimum Value Engineering. Through the use of 24” o.c., stacked stud and joist spacing, single plates, single stud corners and metal connections, some studies of shown that these advanced framing techniques can use up to 40% less lumber than conventional construction. Additionally, the smaller amount of lumber reduces thermal bridging and allows more insulation in the building envelope.
While the living floors provide a more dynamic massing, the foundation level was designed with efficiency and resource conservation in mind. The R-22 Insulated Concrete Forms (ICF) block walls are laid out as a simple rectangle in a block module. These ICF walls are supported by concrete grade beams on timber piles below. The thick window-less walls will keep the floor cooler than the ambient temperature in the summer and warmer than the ambient temperature in the winter.
Durable
Another important aspect of sustainability is long-term durability. In New Orleans, durability inherently requires flood, hurricane, and pest resistance. This home is designed with all living spaces at least 7’-0” above grade, with Bahama-style hurricane shutters (which also provide shading) at all windows not accessible from the exterior, and the provision of “hurricane fabric” screens for all windows and doors accessible from the exterior.
That’s why this house was not only elevated 7’-0” above grade, but it was also designed to have rooftop access at the second floor. Floods will hopefully never make the 7’-0” level, but if they do at least the occupants are provided with the peace-of-mind knowing they have a safe place to get out of harm’s way and wait for help.
Empowerment through Education
Education of the occupant was a particular point emphasized in this project. With the broad-scope of the green measures incorporated into the design of the Phoenix house, it is anticipated that the occupants will be educated at a few different levels. Some education/awareness will occur just because the occupants will see and interact with many of the sustainable features employed on a day-to-day basis. As one example a composting bin was incorporated into the landscape design. Additionally the purpose of the sun-shading shutters, the rainwater-harvesting “HOG’s”, and the largely non-turf yard should be apparent to the occupants.
Furthermore, to keep the occupants fully aware of all the equipment and systems in their house, an operations and maintenance guidance manual will be provided to the owner per LEED for Homes credit AE1. Per credit AE3, the occupants will be encouraged to participate in tours that may showcase affordable green homes given at their home. A third level of education should occur when the owners get their first energy bill and realize how green construction can save green. Beyond the manual, a member of the design/construction team will be charged with personally giving the future occupants an educational session on how to use and maintain the systems in the house. Instructions will include how to maximize passive cooling through stack- and cross-ventilation.
