Architecture
Modern Design Captures Valuable Rain
Instead of letting a precious natural resource trickle away, these architectural features make the most of it
As I type this, New York City is getting pounded by rain, a welcome bit of moisture during a summer when the Northeast and the rest of the country are dry. But as I watch the rain hit the empty asphalt lot out my back window, I can't help but think that more could be done with the rain rather than it being sent directly to storm sewers. Most flat roofs do the same as the empty lot, funneling the water via gutters and downspouts toward a combined sewer under the street. Unfortunately, on its way to the water treatment plant, that water tends to overflow during rain events like this, leading to the "combined sewer overflow" being ejected into the rivers and bays. It's a disgusting occurrence that can be remedied by green roofs, rainwater harvesting and other means.
Design features that do something with the increasingly valuable resource of water falling from the sky are suitable to just about any context, be it a big city, a suburb or a rural area. Here are some ideas for collecting and using rainwater from roofs.
Design features that do something with the increasingly valuable resource of water falling from the sky are suitable to just about any context, be it a big city, a suburb or a rural area. Here are some ideas for collecting and using rainwater from roofs.
One important consideration in rainwater harvesting is the design of the roof. Here is a house with a large overhang that provides more surface area for rainwater collection. If the rain is heavy enough, that extra area makes a difference. Note the cisterns on the far right side of the photo.
A closer look at the cisterns illustrates that the design and placement of these objects are important. These are substantial metal cisterns (I think there may even be one more hiding behind the pair) that are placed at the far end of the house, down a slight slope. The placement reduces their visual impact.
This house has small cisterns in concrete that actually help define an outdoor space. These sustainable features are prominent, expressing the owner's and the architect's efforts. Note the scupper on the low roof feeding the cisterns.
This house does not show its cistern from the front of the house, but the roof profiles work toward feeding it. The pitched roof on the right sloping toward the flat roof on the left indicates that something might be happening with rainwater collection.
A view at the back of the house reveals that to be the case. The bright red cylinder on the right is fed by pipes from the roof above.
Remember the house's front door? Bright red, just like the cistern, which the owners bring attention to but elevate above its inherent industrial character.
But of course not everybody who wants rainwater harvesting wants above-grade cisterns. These below-grade cisterns will be capped by a lawn. While they're fitting for a suburban or rural site, the major amount of excavation required is a downside. As well, any future maintenance will require ripping up the lawn. One needs to balance these various concerns when considering rainwater collection.
This house near Annapolis, Maryland, boasts of water conservation and harvesting via collection and reuse of rainwater, as well as "a 'living shoreline' for breeding of aquatic life," according to Gardner Mohr Architects' description. Further, the landscape is designed for "the infiltration of 100 percent of the storm water onsite." From this view it's clear how the design has influenced each, from the butterfly roof form to the sloped landscape and the rocky shoreline.
The butterfly roof funnels water to one end, capturing the rain with a custom scupper and a downspout.
I can't help but end this story with at least one green roof, and the Mill Valley Cabins near San Francisco are some of the most exceptional ones on Houzz. The series of green roofs let the cabins merge into the dense forest context.
A close-up shows that the terracing allows for access to the roofs. Sedum roofs don't need gardening help like this, but it's important to consider that green roofs slow rainwater runoff while also insulating interior spaces and adding beauty to the "fifth facade"; they also give the opportunity for gardening and even urban farming.
More:
9 Cooling Rooftop Gardens
High Design for the Downspout
More:
9 Cooling Rooftop Gardens
High Design for the Downspout