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Novel rooftop house is attractive. Is it practical?

An unconventional entry in this year's Solar Decathlon brings low-footprint home design to city rooftops. It has pleased the crowds, but not the judges because it has two significant drawbacks: comfort and up-front cost.

Photo by Stephen*Iliffe on Flickr.

This year's Solar Decathlon is being held in West Potomac Park, near the Franklin D. Roosevelt Memorial. The event will wrap up this Sunday, and you can see this home and others if you head down to the event.

Team New York, comprised of students from City College of New York, brings to this year's Decathlon (sponsored by the US Department of Energy) an innovative attempt to embrace an oft-neglected urban surface. Their "Solar Roofpod" is a 746-square-foot home specifically intended to be built on top of the existing flat roofs of the four- to ten-story buildings that cover much of the Big Apple.

"Solar Roofpod" may not be winning in the Solar Decathlon's ratings, but the inventive design has sparked plenty of talk about the feasibility of its premise. At less than 800 square feet, the home resembles in size many Manhattan apartments, but claims to reduce utility expenses by $2,500 annually by generating 11.6 megawatt hours of electricity per year through its solar panel system.

Situated on a rooftop, the home has direct access to light, wind, and water, which the team claims will help reduce overall energy costs in conjunction with the energy-conserving design. The module doesn't neglect to take its "host building" into account either: a steel beam Dunnage Garden built around the home helps protect the building below from absorbing the pod's radiation, and provides space for a rooftop garden.

Photo by Team New York
Despite Team New York's obvious ingenuity, its current standing at number 18 out of 19 participating teams doesn't bode well for the potential feasibility of the project on a larger scale.

Although not all of the ten judging metrics have been scored yet, TNY did not fare well on Affordability, coming in second to last with a rating of 61.4 out of 100 possible points. Affordability is an extremely significant metric in this contest, as the Decathlon touts "cost-effective, energy-efficient, and attractive" home design ideas. Though, perhaps unsurprisingly, the judges' dismal score hasn't hurt the public's impression of the Solar Roofpod. Team New York is currently in second place in the People's Choice Awards, in which the public votes on their favorite house.

From an urban planning perspective, the Solar Roofpod offers a space-conscious solution for building new single-family units in an already fully-developed neighborhood and promotes greater use of solar photovoltaic panels and rooftop gardens. There may not be much room in New York's densely packed streets to build new detached townhouses, but there's certainly open space available on top of its existing buildings to give an individual, or perhaps a couple, room to stretch out.

Solar Roofpod's popularity seems to indicate willingness on the part of Americans to suspend their disbelief and imagine what a city like New York might look like if, on top of large office and apartment buildings, one might be able to look up and see a diminutive home. But because of its shortcomings in practicality and livability—Team New York came in dead last in the Comfort category earlier this week—the idea may fade into the sunset once the Decathlon ends.

Alison Crowley works in real estate development with a focus on drawing educational, health, and recreational resources to neighborhoods east of the Anacostia River. 


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Well, why does it cost so much? And what changes could be made to reduce the cost?

by Tim on Sep 28, 2011 12:33 pm • linkreport

I think this is a cool thing to get conversations started about effective use of space, but wouldn't you get a much greater benefit to more people if you just covered these empty roofs with solar panels?

by Jon on Sep 28, 2011 12:39 pm • linkreport

Interesting concept. It would very limited applicability here in DC though where most buildings are already built up to the building height limits, and for those that aren't, but are in a historic district, there'd be the consideration of it not being visible from the street below. It could be a great idea for new buildings, but then again I think the whole idea of this is 'retrofitting' ... since you can just build a penthouse on a new building ...

by Lance on Sep 28, 2011 12:40 pm • linkreport

I agree with Jon above. This seems like just a very inefficient way to include one more residential unit in a building. I also think it would be quite a pain to have to use the building's roof maintenance access door/hatch to get in and out of my house.

by IsoTopor on Sep 28, 2011 1:52 pm • linkreport

The affordability competition in the Solar Decathlon awards 100 points for any entry under $250K. Above that, there is a sliding scale for increasing expense. Team New York's entry, at $429K, is the second-most expensive home. See

The idea for Solar Roofpod is that the small footprint allows construction of living space on a much larger roof without the necessity of building another floor. On especially large roofs, multiple units may be deployed. See

Unfortunately for TNY, half of the competition has been decided and the team fell into the near-bottom in almost all of them, including dead last in comfort. Too bad, too, because I think it's a great prototype design, but as indicated, too limited for larger deployment.

by Jack Love on Sep 28, 2011 2:50 pm • linkreport

btw, Tidewater Virginia's SD entry (Old Dominion University and Hampton University) also applies an urban fill-in concept by having each unit become part of a larger multifamily building and by sharing infrastructure costs between units.

by Jack Love on Sep 28, 2011 2:56 pm • linkreport

and one more thing (sorry ;-)) ....

The entry from Parsons The New School for Design and Stevens Institute of Technology, called EmpowerHouse, will become a home for a family in the Deanwood section of Washington.

by Jack Love on Sep 28, 2011 3:04 pm • linkreport

It's a very charming idea, but it pretty much can't be affordable by definition -- if you have the zoning allowance, you might as well just build a whole new floor instead of a rooftop house.

by tom veil on Sep 28, 2011 3:50 pm • linkreport

Don't be harsh on the judges. That was my least favorite house. Also, I don't understand why this is different from the zillion of penthouses that dot the skyline.

by beatbox on Sep 28, 2011 4:41 pm • linkreport

I only got through about half the houses last weekend (didn't make it to the NY one), and hope to get through the rest this weekend. Of the ones I saw, the Tidewater, VA, one was my favorite in terms of layout and style. Seemed more comfortable, "homey," and livable than the others, and I liked the look of it aesthetically. I also like the future plans for the unit as part of an urban, multi-unit dwelling.

New Zealand was a close second. Southern Hemisphere, represent!

The Purdue house was probably the largest and most conventional, which would please a lot of people, but I found it suburbia-bland. It might be the first in the decathlon's history to feature a garage, but it looks like a mobile home on the outside. Also, the fact that one of the team members didn't know what "ADA compliant" means was a bit off-putting.

by Banksy on Sep 28, 2011 4:53 pm • linkreport

As a student on the team, the reason why the NY home prototype for Washington DC is expensive is because we are the only home with a PERMANENT FOUNDATION. The steel structural system, designed to hold the weight of the pod and distribute it across rooftops, is what raises the cost. This makes our project FEASIBLE, and not simply a CONCEPTUAL IDEA- not simply a home plotted on a piece of land as every other entry is, but something that takes advantage of the most underutilized space, ROOFTOPS.

by Anonymous on Sep 29, 2011 12:35 am • linkreport

I agree with the student on the team NY. 450 thousand considering what condos go for is inexpensive. If this is practical for the many flat roofed row houses in DC I think it would be a great addition to DC housing stock. On comfort have you seen the Chinese entry or the UMASS "fun house" house.

by Dan Maceda on Sep 29, 2011 10:01 am • linkreport

One consideration I haven't seen brought up by the OP or the comments so far is the issue of relative value of rooftop real estate (in NYC or any major metropolitan city).
Current practice for housing mechanical systems (HVAC, Boilers, etc.) for mid-rise and high-rise buildings is to house equipment on the roof. And even if things like chillers and boilers are in the basement, the cooling towers are inevitably place up on the roof. But by most measures the most valuable real estate for a typical commercial/residential mid-highrise building is at the top.
Take a look at this image comparing two buildings with completely different approaches to rooftop use:

The roofpod goes part way towards addressing the issue, but really, who wants to live on top of a building with a bunch of mechanical equipment - or worse yet, loud fans spinning all the time.

A far better solution - both for property value and efficient energy use is something like the District Heating concept or a Combined Heat and Power plant at the building or nearby.

For local generation, utilizing parking spaces for equipment is a far better use of space: they are are low-value real estate that never pay for themselves anyways (esp. in a place like NYC).

by Bilsko on Sep 29, 2011 10:43 am • linkreport

I wonder how much cheaper it would be if it was built off site and lifted by helicopter into place. They do it with massive (house sized) A/C units all the time.

by Mike on Sep 29, 2011 12:04 pm • linkreport

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