Inspired by the Broadmoor neighborhood context and architecturally driven by the project design requirements, the RAMPed UP house is a clear vision of sustainable and affordable housing for the future of New Orleans. The RAMPed UP house adapts the traditional shotgun typology, modifying it for a modern lifestyle and the needs of the homeowners. The home has been designed to respond to the Broadmoor neighborhood context, the local climate, withstand any future flooding and hurricanes, and provide a comfortable and vibrant environment for the occupants.
Confronted with the challenge of designing a handicapped accessible building elevated seven feet above grade, our house exploits the potential of the ramp as an architectural device to engage the site, direct vision, and mediate the boundaries between inside and out. The RAMPed UP house reconsiders the typical relationship between private and public space. Lifted high above the ground plane, and compliant with ADA guidelines, the ramp serves as a driving organizational force, dividing the lot longitudinally. The diagonal generates two distinct but mutually dependant spaces – the garden/side lot that releases to the street, and the interior of the house, which opens to the back and side. The ramp’s clarity and precise form narrate an elegant sequence of views to the garden.
With the addition of the garden, the house can perform actively in several ways. Spacious windows that connect the interior to an expansive green space along its eastern façade allow for refreshing cross ventilation in both guest and master bedrooms. Building shades and overhangs keep these windows from causing energy and glare problems. RAMPed UP house’s generous length together with the specificity of its shape cushion the relationship from one house to the next in order to maximize privacy while enhancing the conditions for other residents in the area, serving not only the house, but providing much needed visible green space for the public as well.
The seven feet high area below the house will be provided with storage cages for bicycles, yard equipment and extra patio furniture. A rainwater storage system designed to eliminate potable water use for plantings and reduce the impact of heavy rains on the city’s overburdened storm drainage and pumping systems.
ACCESSIBILITY + UNIVERSAL DESIGN
Accessibility was a key driver of the design concept. The ramp leading from the sidewalk to the front door creates a connection between the inside spaces and the outside. Attention has been paid to the architectural details in every room of the house to comply with universal design principles. These details include: an electric range with front controls as opposed to a standard electric range with rear controls; a kitchen sink that accommodates wheelchair access; rotating shelves in kitchen cabinets for easy access; a hand shower with a single lever shower control which enables shower control by those with limited hand dexterity; electrical switches and thermostats mounted at a height of 42” above the finished floor to allow seated and standing access to them; electrical and communications outlets no lower than 18” above the finished floor to allow easy access to them from a wheel chair. These details have been taken into account in the cost estimate, wherever possible.
STRUCTURE + STABILITY
Designing a home seven feet above the ground presents unique structural challenges and opportunities. The structural system has been engineered to resist both gravity and lateral loads (wind and flood) and incorporates the concept of Optimum Value Engineering (O.V.E.) or Advanced Wall Framing in order to couple structural resistance with efficiency and sustainable design. The house is based on a 2-ft module concept with all framing elements spaced at 24” o.c. with windows aligned with stud spacing.
The lateral resisting system composed of shear walls and diaphragms (to be constructed with framing elements and OSB sheathing suitably nailed) has been designed to withstand 150mph wind and incorporates a series of hurricane resistance strategies. The continuity of the load path is assured through a proper layout of all structural framing members, with roof rafters, vertical studs and floor joists all aligned and uniformly spaced. A series of light gauge steel straps (“hurricane straps”) are located at critical points to ensure the load transfer from the elevated framing to the timber pile foundation, 30 feet deep in the ground.
ENVELOPE + SHELTER
Overhangs over the bedroom windows limit direct sun to the bedrooms allowing the homeowners the option of rising with the morning sun without restricting views. Building integrated shades over or adjacent to windows double as hurricane shutters eliminating the need for the homeowner to purchase and install hurricane protection before a storm.
North-South winds predominate in New Orleans. The windows at the front and back of the house operate as they would in the traditional shotgun house. Transoms over interior doors allow physical privacy while permitting breezes to move through the house. The space created by the ramps also allows the predominant winds to blow freely through the outdoor living areas. While North-South winds dominate, East-West winds are not uncommon. The windows and transoms allow effective East-West cross ventilation as well.
In a subtropical and humid climate such as in New Orleans, the building envelope plays a significant role in the performance and sustainability of the home. Humidity, heat, moisture and mold growth are the primary design drivers in the New Orleans climate. The rain screened façade system on the exterior of the house addresses these issues and offers the best performance for hot-humid climates. We have detailed the wall with a generous pressure equalized drainage plane that significantly reduces water infiltration from wind driven rain and allows quick drying after rains cease. The air gap also insulates the house from radiant gains during hot, sunny days. Unfaced insulation and paper free wall boards eliminate common materials for mold growth in the wall build up.
HEATING + COOLING
While ceiling fans and sensibly placed windows reduce by at least 600, the number of hours air conditioning is needed for comfort, both air conditioning and heating will be required for extreme days. A multi-split heat pump system requires no ductwork, is the most energy efficient source of heat in the winter, and allows unoccupied rooms to be left unconditioned. The Daikin multi split system we have selected includes occupancy sensors mounted to the wall mounted units which set back heating and cooling set points on a zone by zone basis; when zones are unoccupied, the heating or cooling load is reduced to save energy even if the homeowners forget to turn off the air conditioning when leaving a room in a hurry. Energy recovery bathroom ventilators bring fresh air into the house while exhausting stale or polluted air when the windows are not open.
ENERGY METERING + PERFORMANCE
Instant feedback is an excellent learning tool. Given the increasingly wide availability of real time electrical usage monitors and analyzers, for example Google Powermeter, we have included in our cost estimate a $2000 line item for equipping the house with a netbook such as Asus Eee PC or Dell Mini 9, electrical service monitoring hardware, and a year of high speed Internet connection for a cloud based real-time power metering and analyzing service. It’s one thing to conserve a few percent with incremental improvements in equipment efficiencies, it’s another to reduce the number of hours that equipment runs by 20-30% by providing users real-time feedback on how they are using energy. Such a system will allow for future integration of real time water usage information as the local utility develops the capability in its water meters.
While real time energy use information is known to change usage profiles, the effects, while very large, are too variable for the rigorous energy model we performed. Electricity use figures for our house have been developed using IES Virtual Environment software Apache tool. While this software is not approved to conduct LEED for Homes building performance analysis, it has been used to both inform the house’s design, as well as estimate the effects of the various energy saving measures included in our home and the energy costs which a resident might see. To quantify the energy savings, as design case and a base case model were created.
Both models were based on the Energy Star Qualified Homes HERS Index Target Predictor Requirements. The baseline building was designed to the Requirements for a single family residence in Climate Zone 2. Where available, actual performance values for selected equipment and materials/construction were used. In the case of the domestic water heating, because the home is being designed to be “solar hot water ready” we have included an estimate of the utility cost reductions possible from upgrading to a solar hot water heater. In a typical month a homeowner for our home can expect to pay approximately $60.00 in utility bills.
The requirements within the LEED for Homes rating system were given considerable weight during the design process. Based on the current design, the house is projected to earn 87.5 points total, comfortably placing it in the LEED Platinum category (minimum 80 points required).
The budget constraint for the home was at driving factor in every design decision. The building was designed and engineered with material efficiency in mind at every step. An Advanced Wall Framing structure was used to reduce the number of structural members while maintaining the hurricane and flood resistant integrity of the house. All plumbing fixtures are aligned on a single axis to minimize the complexity of the plumbing system and reduce the amount of piping that must be installed. The single wall design also enables significant prefabrication of the plumbing system reducing on site time for plumbing work. Windows were dimensioned at nominal four foot and two foot widths so they could be installed between studs with minimal modification to the advanced framing structure. Usual cost savings measures of reducing the cost of fixtures, finishes, and materials were also undertaken, with an effort to retain quality. Our cost estimating strategy relied upon both the competition cost template and industry data sources such as RS Means, vendor information, and publicly available information from retailers such as Home Depot and Lowes. Taking all cost saving measures into account, the final construction cost of the RAMPed UP house is estimated to be $99,185.