By: Kevin Duffy
Most people consider their roof to be just another part of the building assembly that needs to be maintained and replaced approximately every 20 years. While this may be true, roofs can be transformed from ugly barren stretches of black tar into beautiful, recreational, leisurely, entertaining, and eco-friendly spaces. New York building owners have been at the forefront of this transformation. Just consider the ever-growing popularity of rooftop bars around the Big Apple. While building owners and occupants dream about and aspire to create these unique expanses with bird’s eye views, so much is involved in their creation and many buildings are not suited for them.
The first step is for building owners to decide what they would like to do with their roofs. Some of the most popular options are installing solar panels, creating a green roof, and converting rooftops into sun decks or other recreational spaces. Each choice has its own set of pros and cons, but all are wonderful transformations of the unused space of the common roof.
The next step when contemplating a roof conversion or adding a rooftop structure is to retain a structural engineer to review the building and ensure it can handle both the dead and live loads associated with the roof improvement being considered. The dead load is simply the weight of any structures, or permanent objects to be placed on the roof. Examples might include: pavers, gazebos, planters, etc. The live load is anything that is movable, including people. The structural engineer will determine if the building can safely support the load weights as prescribed by the NYC Building Code. If the current structural system can’t support the roof improvement plan, other options can be considered. Loads affecting the new roof space could be lessened or limited. More costly solutions might involve adding new steel, wood, or concrete beams, or reinforcing existing beams with carbon fiber. If the structural engineer determines that the building can support the proposed loads without having to spend a lot of money on reinforcing the existing building structure, building owners are a big step closer to enjoying their new roof space.
A qualified building envelope professional can now be retained to design the project, and oversee the bidding process, DOB filing, and construction administration. During all phases, the code requirements laid out in Section 1509 of the NYC Building Code must be strictly adhered to. Even before construction begins, finalization of design, bidding and contractor selection, and DOB filing can take anywhere from 18 to 36 weeks, and even longer for more complicated designs.
As building envelope consultants, “Can we revamp our roof to make use of that space?” is a popular question we often hear. While we wish we could immediately answer that question just by looking at the structure, there are unknown factors to be investigated and determined. And even when the answer turns out to be yes, it’s definitely not as simple as throwing some lawn chairs and coolers on the roof and having a party. The planning, processes, phases, inspections, decisions, meetings, oversight, and regulations that are involved can make the road to the finished product a long and complex one. But as in all highly desirable things in life, enjoying great open-air views and leisure time with neighbors, family, friends, or coworkers from your beautiful renovated rooftop space might be well worth it!