Setbacks, Sideyards and the reason we can’t put a window there


In construction terms, a setback means more than discovering an unexpected concrete beam where you wanted to cut a doorway.  Setbacks refer to the distance between the edge of the property and the edge of a building.  Today we discuss how they vary and what that means for design and construction projects.

What is a setback?

Put simply, setbacks dictate how much space is required at the front, sides and back of a property between the building and the lot line.  While many of the rules that govern building design are set by the local Building Code, this regulation is part of the Zoning Ordinance.  Here’s a great post illustrating the difference between the two.  Zoning divides a city up into types of areas – residential, commercial or industrial – and then regulates the building types, sizes and safety requirements and even the number of parking spaces they need to have.

This link, Second City Zoning, shows the different zoning types (and their rules) here in Chicago.

Downzoning – What happens when the setbacks change

Yet again, this post is brought to you by a recent client conversation.  In this case, we were discussing potential layouts for a two story loft in a 19th century warehouse building in West Loop.  We’d been out to the site to field measure the building a few weeks earlier and hit the drawing board hard to workshop multiple floor plan variations.  When we met, the couple were pleased, citing more possibilities than they’d previously considered.  “But,” noted one client, “it seems like you overlooked the chance to open up any new windows in this East wall.”

In fact, we hadn’t missed it … we just knew it couldn’t be done.  That wall was right on the lot line and very close to an adjacent building.  Even though there had once been a window in that wall, now that its bricked up, we can’t re-open it now.

How, you might well ask, did their building come to be BUILT right up to the lot line when zoning requires setbacks that prevent us from adding or even un-bricking former window openings?  It is probably a result of downzoning.  (We’ll be posting about that pernicious process in greater detail soon.)  The short version is that zoning can be changed after buildings are already constructed.  Adjusting the zoning “down” means allowing less density (zoning is almost NEVER adjusted up) reducing the chance for mixed use development, adding parking requirements, and increasing setbacks.  When the zoning changes, existing buildings are allowed to remain but new construction – or remodels – must take the new regulations into account.

Different Zones, Different Setbacks

Setbacks – and other zoning related requirements – change dramatically from one zone to another and between urban, suburban, and rural areas.  This illustration of setbacks and building heights from shows a typical suburban arrangement.  Very little of the lot (30%) is build-able, and the house must be set back 30 feet in front, 10 feet on either side and allow parking space for a car on the property.

single family setbacks

A stroll around any Chicago residential area will show much greater density.  Even in areas with single family homes, the side setback won’t be more than 5 feet – in multifamily areas it may be as little 2 feet – allowing just enough room for a sidewalk to run between houses.  Buildings will be closer to the street too; a 20 foot setback is normal in Chicago.

In business districts the front setback will often be zero, with buildings nestled right up against the sidewalk.  This is a very pedestrian friendly layout since it encourages window shopping and keeps eyes on the street.  Its also very normal to have no sideyard requirement – with buildings right next to each other or even sharing a party wall.

Do Setbacks have an Upside?

At moss, we spend a lot of time arguing for density.  It’s not that we don’t like open space, we just think that, if you are going to live in a city, you should want to maximize its potential.  Keeping buildings close together maximizes city services, makes transit more efficient and puts everything the city has to offer closer at hand.  We think American already has way too much lawn anyway.

But is there an upside to the setback?

Restricting the amount of lot area that buildings can occupy does (potentially) increase the permeable surface area of the city – which is very important for preventing runoff and literally keeping sewage out of our river.

Setbacks at the front are often used to run public utilities under yard space.  That’s practical.

Regulating space around and between buildings can also ensure that they get sufficient amounts of light and air into each residential unit.

Separating buildings reduces the odds that if one catches fire, the neighboring structures will also be damaged. (Never underestimate Chicago’s paranoia about fire.)

These are all valid “pros” in favor certain setbacks.  Still, we still hate to see a property or area downzoned, and we wish we could put some windows back in that East wall of the property mentioned above.

At the end of the day however, moss projects are all about working with the existing conditions.  Setbacks are just one more design parameter that will help prompt interesting solutions.