Title: Haw River Net Zero House
Location of Proejct: Pittsboro, NC
Project Completion Date: January 2020
Firm Name: Arielle Condoret Schechter, Architect, PLLC

Short Description: “The Site is your Building” was the guiding philosophy behind the design of this modern, net-zero, riverfront house.

The site is harsh; power outages are frequent and the well produces only 1/2 gallon per minute. But the design solves these problems with a graceful butterfly roof that channels rainwater to two giant cisterns, solar panels, a geothermal heat pump, and a PV backup battery system.

Trees bending over the river inspired the cantilevered forms. The open interior is graced with natural light and cross ventilation. Generous porches and decks extend the living spaces toward the river, providing sweeping views.

Architect's Statement: A client couple with profound love and respect for their riverfront site inspired the architect’s graceful and sustainable design solution.

The site, a 21-acre thin strip of river frontage, had many restrictions due to flood plain and riparian buffer zones. There was a natural place to perch the house however: a small knoll overlooking the rapids on the north end of the site.

The site challenges were many: the location is rocky; the weather harsh; the location is remote and suffers frequent power outages. The existing well provides only 1/2 gallon of water per minute.

Form givers:

The architect found inspiration from the riverbank trees, many of which were deeply bent over the river, almost horizontally. These tree forms were echoed in the design with cantilevered decks and porches that reach toward the river.

An enormous boulder on the site has a central cleft forged by water over millennia. This natural water channel inspired the butterfly roof with its central gutter.

The plan is linear, reflecting the horizontality of the river and allowing each main room to have a view of the water.


Sustainable Solutions:

The architect specializes in net zero and sustainable residential architecture. But this site’s limitations mandated even more proactive solutions, among them a rooftop water collection system; rooftop photovoltaic array; geothermal heating and cooling; and passive house rated windows and doors among other strategies, which bring the house to net-zero.

The PV system has a battery backup. The geothermal system is fed by 3 deep vertical wells. The rooftop water collection system channels rainwater into two 5000 gallon above ground cisterns. The cisterns are massive out of necessity, but the butterfly roof is delicate and floats above the house, sheltering the main living spaces inside.

The butterfly roof has a carefully designed central gutter leading to downspouts on each end of the house, funneling 100 percent of the rainwater reaching it into the cisterns, which in turn carry the water to a triple filtration system designed to kill 99.9% of bacteria that may appear in rainwater. In the final step a UV light system kills any bacteria that may have hidden or “shadowed” behind others.

This North Carolina county has never approved a residential potable water system, and will require 12 months of data showing the bacterial content of the collected water to be submitted before the system can be graduated from a gray water to a potable system. Early numbers indicate the triple filtration system will purify water to exceed the county’s requirements. In that sense, this project will be a valuable test case for the future of potable residential water collection in the area.

Livability:

This project is designed to a high degree of sustainability, but there’s an equally luxurious side to the Haw River House. The architect believes strongly that only the most livable and pleasant spaces are sustainable in the long run because good spaces stand the test of time and are more immune to tear downs and alterations, and therefore minimize waste.

The interior footprint is a relatively small 3 bedroom house, at 2600 heated square feet. But there are multiple exterior spaces, such as screened and open porches, decks and terraces on the river side that extend the living space into nature. The architect encourages clients to build smaller houses, but of better quality, and always including outdoor spaces.

The interior is very well day lit and open, requiring no electrical lights during the day. The wide expanses of glazing include a 20’ wide custom passive house sliding door facing the river.

This sustainable house is also sybaritic. Each of the full bathrooms has a passive house corner window. The master bath features a soaking tub with a fireplace. The outside terrace on the lower level has a hot tub and soaking pool with an infinity edge overlooking the rapids. A space is allocated on the lower level for a future home sauna.

The natural and unobstructed flow from inside to outside encourages interaction with the outdoors from almost every interior space, making this a year round house with the feeling of a vacation house, with the owners’ happy knowledge that they have built a project that fits their site and tries to be respectful of the planet’s limited resources.