WHY WE NEED TREE ORDINANCES

Residential Development Prior to the 1980s in Atlanta.

As Atlanta developed in the early 1900s beyond the core downtown area the city expanded into densely forested land. Some of this forest was old growth and some had been logged with native species regrowth. Frequently home footprints were relatively small, and lots were cleared only to the extent needed to build the house and provide paving for driveways and walks. This preserved trees for shade as this was prior to air conditioning.

Residential Development after the 1980s

Redevelopment and renovation began to surge in the 1980s in metro Atlanta’s core areas as more residents sought intown housing. Property values rose to a ‘tipping point’ that made single family lot redevelopment feasible. Today, developers see maximizing house size as their path to maximum profits.

The city of Atlanta’s zoning allows lot coverage up to 50% of the lot (on R-4 lots, the predominant single family zoning) and builders have been prone to build to this 50% limit wherever feasible. In order facilitate construction (and quick sales) of larger new homes, developers have shifted toward removing most or all trees whose root systems would require more care and planning to build around them. On many lots this means the entire lot is cleared and ‘mass graded’. Compared to the earlier period, where homes were often built to fit the lot, lots today are increasingly reshaped to fit the house. As a result, trees in side and rear yards that had been preserved in the first wave of building are now being removed to accommodate larger homes with garages and swimming pools.

Creation of Tree Ordinances

The broad sweeping uptick in the amount of tree cutting and grading done for homebuilding caused many to become concerned about tree loss with no required replacement and led to the first tree ordinances in our region in the early 2000s. The first ordinances typically required a builder to plant a tree to replace a tree that was cut down. But people soon recognized that the loss of a large oak could not be replaced by one small sapling, so the next phase of tree ordinances required replanting the same number of diameter inches of trees as the amount of inches of trees cut. So rather than replace one 30" tree with one sapling, it would be replaced with 15 two -inch caliper trees. This was still not an equivalent because 15 little trees still do not offset the loss of one larger tree. For example it takes many decades for newly planted trees to create comparable shade, and planted trees in urban graded soils often don’t survive long term. 

The value of mature canopy trees cannot be matched by younger trees in any service, from cooling to carbon sequestration to stormwater runoff. For example, a 100-year overstory tree takes more carbon dioxide (greenhouse gas ) out of the atmosphere than a 50 year tree, even if all of its 50 years of carbon absorption are added together.  

Because of current building trends, and because metro is a hot spot for selling real estate, we are losing more trees than ever - nearly 1/2 acre per day. Replanting cannot keep up with the increasing loss, and even with replanting, we consistently lose higher value urban forest and hardwoods, replacing them with smaller, shorter lived street trees. Today we must work to preserve more existing trees, even as we build new homes, and find the balance between building and preserving enough of our natural landscape to build safe, healthy sustainable livable communities.  

The tree replanting requirements in TPOs like in Atlanta and DeKalb County must be amended to require preserving more trees. Every tree cannot be saved, but a more creative and flexible approach to siting and designing homes on lots will allow more of the highest value trees to be preserved. Some builders and architects have known and practiced this approach for years and have been willing to take the extra care needed. Most builders resist because it is easier and more convenient for them to apply mass grading techniques used in large suburban developments to intown lots.

Help us create tree ordinances that accomplish a better balance between building and preserving or best trees.    Contact us.

For information on the health benefits of living with trees click here.