Philadelphia Zoning Guide: CMX Building Overview

Welcome to Permit Philly’s Philadelphia Zoning Guide!

I was recently at a neighborhood meeting where a member of the group casually observed that the Philadelphia Code allows for an 8.5-foot-wide garage, but should really allow only a 9.5-foot-wide garage.  If you are this person, you might not need this blog post.  But for most of us in Philly – and especially for developers and ambitious homeowners – It’s useful to go over the uses and general Philadelphia zoning rules about buildings to get a sense of what the City does and doesn’t want.  So here’s our Philadelphia zoning guide series.

First, we’ll handle the commercial buildings that also allow residential use:  Commercial MiXed-use, or CMX.

There are six categories of CMX buildings in the Philadelphia Zoning Code:  CMX 1-5, with CMX-2.5 thrown in the middle.  CMX-1 is the smallest sort of building; five is the biggest (it’s the opposite for residential uses, where 5 is the smallest category).

If you’re wondering, “What is a CMX-5 building?”, the answer is:

Comcast Center Philadelphia

So, most developers in Philly are not building that.  But there’s a lot of CMX to go around, and developers are after it.  Here are the things you should know about CMX:

CMX Philadelphia Zoning Guide

Mixed-use buildings mean that you can have a “main” use for a business and also a “main” use for residences.  How are two supposedly main uses each the main use?  I don’t know!  Don’t worry about it.  In other zoning classifications, your development project will get rejected for having “multiple main uses.”  (See an example!)  But the CMX designation is there because some buildings in a city – actually, a lot of them – should have more than one thing going on.

CMX buildings are buildings designed for businesses to use usually on the lower floors.  On the upper floors, residences (or more offices) can flourish.  The biggest CMX buildings are very tall or even part of the skyline.  The smallest are very likely on or near your block.

You can use all or most of these buildings for many, many different businesses.  You’d have to check the Philadelphia Code itself for up-to-date and complete reference, but our Philadelphia zoning guide can confidently say that in any CMX building except CMX-1, you can open a hospital or a (medical!) marijuana dispensary.  (We’re just letting you know the rules, people.)

CMX-1: The Neighborhood business

CMX-1 buildings are designated by the Philadelphia Zoning Code for “accommodate low-impact, small-scale, neighborhood-serving retail and service uses in storefront buildings, as well as the types of residential uses allowed in surrounding zoning districts.”

You can probably figure that out on your own, but I called this a Philadelphia zoning guide, so I’ll guide you anyway:  These are buildings that can be either homes or businesses.  However, for whatever reason, you can only have an office on the first floor.

Most household uses – like, condos or single-family homes – are allowed in CMX-1.  But this designation is all about what’s allowed in the neighboring districts:  If there’s a building next door that’s taller than the regular house height, then you’ll be allowed to build your CMX-1 property a little taller.  If the neighbor’s house is a duplex, then you can have a duplex.  CMX-1 depends a lot on the neighborhood, so be careful when buying or building or selling.

(Or just contact Permit Philly.  You know.)

CMX-2 and 2.5: The Neighborhood business, again, but bigger

CMX-2 buildings are like CMX-1 buildings, but they were probably designated with a 2 or 2.5 because they’re a little bigger.  (Listen, not all of the Philadelphia zoning guide will be super complicated.)

The key thing to know about this kind of building is that the Philadelphia Zoning Code demands that you keep the bottom floor as a business.  No full condo buildings here, or houses; unless you get a zoning variance.

CMX-2 has tighter restrictions on the number of housing units that CMX-2.5:  If you’re trying to get a really, really small apartment in a CMX-2 building, you’ll probably have to go through the zoning board.  A CMX-2.5 building can also be a lot taller than a CMX-2 building, which has to stop at 38 feet like a normal house in Philly.  There are other smaller differences in the allowed size of a CMX-2 and CMX-2.5 building.

CMX-3: A Bigger Slice of the Pie

Hey, now we’re getting up there!  CMX-3 buildings aren’t expected to pop up in residential neighborhoods.  Accordingly, you can’t use them for homes for one family, or for duplexes.  But you can build a lot of condos there, or a lot of office spaces.

There are some unusual allowance for a building zoned CMX-3, and they’re often linked to CMX-2 buildings.  For instance, you can use CMX-3 and 2 (but not 2.5!) for surface parking if you get a special exception from the zoning board.  It’s the same deal for nightclubs or private clubs.  So if you want to do something super cool (or a little dirty; we try not to judge here), it helps to be working on a CMX-2 or 3 lot.

(Or, like, if you really really want surface parking.)

Also, fun fact: a “vehicle fueling station” is only allowed on CMX-3 lots, after a review by the zoning board.  So if you want to open a gas station…

CMX-4:  You Can See It From Your House!

Obviously, by this point you are not allowed to use this building as a duplex.  We’re in Center City; building large.

And equally obviously, we’re way past building a cute home for the family.  In fact, the Philadelphia Zoning Code specifically says that CMX-4 is intended to “accommodate a broad range of nonresidential uses.”  So, go nuts!

… okay, don’t go nuts.  At this level, you’re basically certain to have to work with the City Planning Commission (not to mention the streets and water departments) to get a building up.  And there are still some things (like, you know, a gas station) aren’t allowed even on this hallowed commercial ground.  But unlike in residential districts, you don’t have to worry too much about being allowed to open a restaurant.

CMX-5:  The First Building That Shows Up on a Philly Google Search

A CMX-5 building is a building in the “Center City Core Commercial Mixed-Use district.”  So, in English, that’s downtown; or for us in Philly, Center City.  Obviously, you can put some condos in here, but you can’t use the Comcast Center as a single-family home (even though that would be so cool).

When you’re at this level, you’re going to need more than just some permits: you’ll need meetings with the City Planning Commission and probably the City Council.  I’m not telling you how to build your skyscraper; just, you know, don’t try it without doing your homework.  I personally have never tried to apply for a skyscraper permit without telling anyone about it, but I assume it would raise some eyebrows.  Get funding and dig in, is probably the advice here.  But you’re building a skyscraper: you knew that already.

The Philadelphia Zoning Guide Will Return!

If you’re all, “Wait!  I want to read more!” then first, thank you!  Permit Philly loves you too.

But more importantly, there will be more posts covering basic residential uses, and then more posts after that covering the uses of Philly buildings in detail.

Until then, thanks for reading!  And feel free to shoot us a message if you have any more questions.

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