Green Roof retrofit System
The problem: Adding a green roof to an existing historic row house can be difficult and expensive because the roof structure was not designed for the extra weight. In such cases, the roof joists have to be reinforced, which can be expensive and disruptive.
There are many benefits to a green roof:
- Green roofs reduce the internal temperature of the building below
- Green roofs reduce the urban heat island effect
- Green roofs can provide fresh produce
- Green roofs can provide refuge for indigenous birds and wildlife
The Solution: This design solves the problem by using the existing masonry walls to bear the weight of the green roof system. This green roof sits above the existing roof as illustrated below.
Below, Metal attachment rails (red) have been attached to the top masonry walls.
A series of lightweight trusses (red) span the roof. Here they are shown at 2′ intervals.
Planting bins are placed between the trusses. These bins are designed to hang from the top of the truss. The growing medium and vegetation will be placed in these bins.
Bins are added across the roof.
A walking surface is installed. These pavers snap into the trusses just like the bins. They provide easy access to the entire green roof. This is important if the roof is going to be used for produce, however, a roof of only bins can be used if the roof is going to be planted with indigenous vegetation.
Finally, growing and drainage medium are added to the bins and vegetation is planted.
This is, of course, only one possible arrangement of bins and pavers. The system can be organized in any number of ways.
Tags: architecture, city, design, garden, green, green roof, rendering, retrofit, roof
