Yo, Data! Now compare roof decks citywide

Yo, Data is an occasional feature by tech whiz and South Philly resident Angela Minster, in which she crunches the numbers and makes ‘em all nice and pretty. Know of any data sets you can customize to South Philly? Let us know at punk@passyunkpost.com.


Last time, we looked at roof deck permits in South Philly for the last seven years. We found that Graduate Hospital had by far the most roof decks added (both in total and as a proportion of buildings in the neighborhood). This week we looked at how South Philly neighborhoods stack up compared to the rest of the city.

Roof Decks Added per 100 Residences by Neighborhood Since 2007

The neighborhood that has added the most roof decks (as a proportion of all residential buildings) over the last seven years is the Francisville neighborhood (east of Fairmont and west of Broad), followed by West Poplar (East of Broad from Francisville) and Graduate Hospital. HALF of the top ten neighborhoods are South Philly neighborhoods.

Are new roof decks an indicator of development? If so, an interesting perspective to take from the data is to look at the how the rate that neighborhoods add new roof decks has been changing. The question is: which neighborboods are adding progessively more roof decks each year and which are adding fewer?

The next map shows that our very own Point Breeze has been ramping up roof decks at the second highest rate of any neighborhood in the entire city at a rate of an additional 89 roof decks added each year. The fourth lowest rate of change is coming from Point Breeze’s neighbor to the north, Graduate Hospital, where we see the total roof decks added slowed by about 33 roof decks each successive year.

Rate of Change in New Roof Decks by Neighborhood

Finally, if you think that roof decks are only being built through new construction (making this more a post about new construction than about roof decks), you’ll be interested to know that only 47 percent of roof deck permits were associated with a new construction or complete renovation permit.

What do you think? Are roof decks a good indicator of development? Do the maps match up with your impressions of local development?

The Fine Print: Roof deck permit data from the L&I API, only decks listed as in progress or complete were included. Residential buildings include multi-use buildings, data from city 2015 tax assessment data. Neighborhood delineation comes from Azavea Commons. Thanks, Azavea!