NoLa[PH]

 NoLaPH is intended to be a low-cost, low-tech and easily
constructed CO2 reducing Passivhaus. NoLaPH achieves Passivhaus and moves
beyond carbon neutrality without costly triple-pane windows and over insulated
envelopes, ensuring a truly affordable, sustainable and comfortable home.

Design

NoLaPH is a play on the traditional shotgun typology,
with a pivoted gable roof and a pushed-out bay. The rotation of the roof allows
for a clean, modern take on a traditional ‘shotgun’ while also being efficient
for rainwater harvesting, solar harvesting and effective shading of the house. The
pivoted gable allows tall, naturally lit spaces. The hallway is re-purposed as
a semi-public space, with a full-length study area.

The pushed out bay allows for more outdoor living area than a traditional
shotgun. While this creates a higher surface area to floor area ratio, the
optimized envelope and fenestration allows achievement of the Passivhaus
standard with minimum effort. The additional decks effectively double the area of
the house while allowing a multitude of variegated daylight and natural
ventilation. They also make for legendary house parties.

Environment

NoLaPH is a durable structure that has the ability of
being completely deconstructed and recycled. Though intended to be
stick-framed, NoLaPH is pre-fab friendly and could easily be adapted to
prefabrication or panelization systems. Precast concrete piers require minimal
site disturbance. Low/No-VOC finishes are selected for occupant health. The
materials used are low-carbon products with minimal embodied energy and Global
Warming Potential (GWP). The utilization of photovoltaics + Passivhaus allows
for one of the first CO2 reducing homes in North America,
meaning that not only is the house CO2 neutral/plusenergiehaus, but it is actually reducing the carbon footprint
of its non-Passivhaus neighbors.

Energy

Achieving Passivhaus significantly reduces the heating
and cooling demand of NoLaPH. With a peak cooling load of less than 4.26BTU/sf,
a traditional mini-split is actually oversized for the house. Utilization of a
hot water heat pump, which conditions the space as it heats water, further
reduces the energy while assisting in active cooling. Compact fluorescent
lighting, energy efficient appliances, adequate daylighting and reduced
reliance on active heating and cooling push the specific primary energy demand
to 27.4kBTU/ft2a. With the installation of a grid-tied 3kW photovoltaic system,
more energy is produced than needed on an annual basis. Thus, not only is
NoLaPH low-cost to construct, it is also low-cost to operate.

Water

NoLaPH’s monosloped roof allows for harvesting rainwater
to a single or multiple points. A rainwater harvesting system is intended for
nourishing “edible estates” on the lot, while reducing the demand on a decaying
infrastructure. With incorporation of a properly sized tank, biodigester and city
approval, NoLaPH could be net-zero for water as well.

Envelope

The reclaimed cypress and fiber cement rainscreen is
durable and ensures water shedding. The polyisocyanurate insulation manages
inward vapor drive and reduces thermal bridging. All wood is treated with
non-toxic borate. Drywall is paper free to reduce mold buildup. Because the 2x4
wall is uninsulated and an interior air barrier is not utilized, all walls can
serve as MEP chases, keeping the cost of construction low and reducing the likelihood
of air barrier degradation. Utilization of shaded double-pane wood-clad windows
with low-SHGC ensures comfort in a hot/humid climate without sacrificing
aesthetic or environmental impact.

Air
Barrier

The air barrier used is borate-treated plywood taped with
Siga or 3M to ensure airtightness.

Ventilation

Utilization of an UltimateAir
Recouperator Energy Recovery Ventilator (ERV) and MERV13 filters ensures
superior indoor air quality. The inverted roof trusses allow duct runs within
the thermal envelope/air barrier, as well as incorporation of down lights.

Heating/Cooling

Though the house is incredibly diaphanous and can operate
through most of the year without reliance on heating or cooling due to the
optimization of the façade and windows, supplemental heating and cooling for
extreme days is provided by a 1-ton mini-split system. The utilization of
multiple decks allows for adequate passive ventilation during the day and night
cooling in summer.