More case-study research for Net-Zero development, offering some modest examples to augment some previous developments. For starters, via Jetson Green is the High Street Philadelphia project is being developed by home(scale) in a former brownfield zone in downtown Philly. The most urbanized version, this was originally shown as a very vegetated facade in early renderings from mid-2007:
:: images via Jetson Green
These images are from a more recent post, showing building refinement but less overall greening (or a different facade? I can't tell. Either way, this project is very cool, and is similar to the previous net-zero case studies using green roofs and vegetated walls to provide energy mitigation as well as amenity and stormwater management.
"...22 townhouse units incorporate sustainable features rarely attempted in smaller residential projects, including heat recovery ventilators in each suite and stormwater recycling for flushing water and irrigation. These somewhat unusual approaches, combined with more traditional green initiatives—including dual-flush toilets, radiant flooring, double-glazed low-e argon-filled windows, occupancy sensors, and abundant daylight."
:: images via BDCnetwork
Definitely a case-study in green being a market advantage, part of the reason. From BC+D, the developers, "...decided to best the competition by going all out on advanced green features and high design. While other developers were building condos with a few 'light green' features..." This all led to better sales, even though comparably priced to single-family homes and similar condos, or just a slight percentage more in cost.
Another example from the US, is the Cromley Lofts, according to Treehugger, the first LEED-certified Condos in Virginia (Gold rating). The major component with this project, and similar to many net-zero is the modesty of size and scope, while being packed with green features. A few, via their website:
:: images via Cromley Lofts
A major component is the ecoroof, which is typically more effective for energy-efficiency in single-story or smaller scale multi-story buildings, because of a high ratio of roof to skin surface, compared to a high rise. The following shows seasonal variation of the vegetation as well.
:: image via Cromley Lofts
:: image via Treehugger
The final net-zero entry is from the UK, and is non-vegetated, but does delve into spatial re-arrangement plus high-tech solutions by creating a curved facade that provides maximum daylighting with minimal energy loss. Via G-Living, the BRE Lighthouse uses form, as well as a 'high-performance Structural Insulated Panel (SIP)" which provides a large amount of thermal insulation which reduces heat-loss by two-thirds from a standard design. Check out all of the projects at the BRE innovation park.
:: images via GLiving
The modest scale of some of these projects is starting to show that there are many technologies and opportunities that work on residential scale buildings. One aspect of acheiving net-zero is having less volume to condition, making it easier to use less and conserve more. While some are not-necessarily designed as officially net-zero, which is kind of a moving target anyway, the writing is on the wall that more models will being built around the world, making it a sure net-gain in net-zero.