Site: New York City, Hell's Kitchen. 10th Ave on the corner between 49th and 50th street.
My design comes with some quite interesting challenges. Natural challenges and Design Challenges. After giving my site some serious thought I decided to go with a narrow building or two. Having a tall skyscraper has its ups and downs and trying to beat an ASHRAE standard is pretty difficult. Below are some images of the most important sustainability goals.
The benchmark comparison. I was able to get the kBtu below the 90.1 standards on the single tall tower but not on the two tower concept I tried first. I believe this is because of all of the sun that the single tower gets. This would let me use a variation of different systems to help shade and cool the interior spaces.
Since my site is fairly narrow and there really is not much room, I have landed my conclusions on making the tower(s) rectangular and thin to get the most room. The masses would be a series of interconnected shapes optimized for each program use. I was thinking of having the lower floors entertain the idea of parking, a lobby space, connecting to the subway, and office spaces. As you travel higher into the tower(s), the program would switch to residential spaces and on top a hotel or a restaurant on the highest level.
Above the image is representing one tower, and below for two.
Each floor to floor height will exceed what is usually the desired 10' floor height. This floor height change will allow people to have a sense of openness. I can copy this openness effect to help with sustainability features such as Daylighting and Shading. Depending on how tall the tower(s) will actually be will determine how much shade the surrounding buildings will have. Since the site typically gets New England weather, This design will have to be compatible with snow and very cold temperatures as well as 100 degrees temps in the summer.
The single tower is what I am leading towards after the analysis. It is not represented in the concept model, but I would like to apply a "pixilation" effect to the main core of the tower once I have the height nailed down. This will bring the standards shown above through the roof, helping out with natural ventilation, rainwater collection (due to more cantilevered roofs), Shading, and Daylighting. Have an cantilevered effect already helps with cooling the building down and lets the user awareness become more apparent with balconies to let green features in.
While the energy use will be high (skyscraper), I believe it will be necessary. The 3rd floor terrace below could allow residents to get good fresh air, or share a common community. It also has the potential for solar panels. The façade of the skyscraper will have to accommodate for solar gain, and help shading and cooling as well.
In conclusion, sustainability in a large skyscraper is definitely possible even in the most non-green urban areas such as the heart of New York City. I look forward to try and push the final design of this tower below ASHRAE standards and hopefully give the standard citizen a sense of pride and comfort as they walk through this skyscrapers hallways.