Chart of the rain fall records in Philadelphia from 1973 to 2009
From the chart above, it is be concluded that the amount of precipitation in Philadelphia varies greatly by year. It is also believed that the building can be design in such a way that no storm water hits the ground and goes into sewers. With this mindset, the group has decided to go for a LEED certification and making the building green while designing for a 100 year storm since green innovative buildings tend to last more.
Figure showing single line diagram of building and site
Green Roof
Above is a simple line diagram showing just two things: the green roof on top of the building and a permeable pavement on the whole site. The size of our building is 100ft by 180ft. Therefore its area is 100'x180'= 18,000 square foot which is also the impervious surface before construction. The permeable area after construction due to the green roof will therefore be the same as the area before construction: 18,000 square foot.
By definition, a green roof is a roof that is partially or completely covered with vegetation and a growing medium, planted over a waterproofing membrane. In this case, the roof will be completely covered to avoid any water from running off and causing the need for a drainage system. Green roofs may also include in some cases additional layers such as a root barrier and and irrigation systems.
The reasons behind choosing a green roof are as follow:
By definition, a green roof is a roof that is partially or completely covered with vegetation and a growing medium, planted over a waterproofing membrane. In this case, the roof will be completely covered to avoid any water from running off and causing the need for a drainage system. Green roofs may also include in some cases additional layers such as a root barrier and and irrigation systems.
The reasons behind choosing a green roof are as follow:
- Interaction with other systems (HVAC in this case): a 2005 study by the University of Toronto showed that green roofs can reduce heat loss and energy consumption in winter conditions;
- Reduce cooling loads of a building by 50 to 90%;
- Interaction with the plumbing system: reduces storm water run off (up to about 75%);
- Can extend the lifespan of a roof by over 200%;
- Could increase the real estate value of an average house by about 7%.
Permeable Pavement
Students have decided to make the site 100% permeable. The pervious area is therefor 200'x380' = 76,000 square feet. Although this may seem unreasonable, it has a lot of benefits.
- Managing runoff: permeable paving surfaces have been demonstrated as effective in managing runoff;
- Controlling pollutants: keep the pollutants in place in the soil or other material underlying the roadway;
- Trees: permeable pavements give urban trees the rooting space they need to grow to full size.