Friday, Jul 12th

Neighbors Ask the BAR to Save a 300 Year-Old Tree

OakTreeAutenreithThe following comments were submitted to the BAR by Bill Roberts of 15 Autenreith Road:

Re: Application to Board of Architectural Review for 21 Autenrieth Road, July 8, 2024 Meeting

Good Evening. My name is William Roberts. I live at 15 Autenrieth Road and have done so for the past 25 years. This is the fourth time this house at 21 Autenrieth has come before this Board. Each time, those of you who were reviewing it for the first time all had the same initial reaction: The garage does not belong in the front yard. It is out of character both for the neighborhood and for this house. And, the changes in grading and insertion of a retaining wall needed to put the garage there is like putting a square peg in a round hole. Moreover, these perturbations to the front yard will put an historic, beautiful oak tree at grave risk. I think that in your own hearts and minds, you agree that using one of the two existing two-car garages or siting a new one in back of the house or on the other side of the property away from the oak tree is the right thing to do. There are several reasons why I say this:

1. This house is a remarkable example of a brick Georgian-revival home. Moving the garage to a prominent place extending in front of the rest of the home will substan+ally detract from its curb appeal and meaningfully alter the character of the neighborhood in a detrimental way.

a. I realize that you have previously asked the architect and builder to look at other less intrusive options, but there really are several options that could provide adequate or better sited parking.

  1. The clearest course would simply be to use either of the existing two-car garages. I realize that the proposed design would use these structures for other purposes. However, since the current investment group owners plan to spruce the house up and sell it without ever living in it, there is no way of knowing what features the people who will eventually live in the house would prefer.

  2. Another alternative would be for the exiting brick Georgian revival, detached garage to be disassembled, moved, and attached on the same side of the house as it currently resides.

  3. Finally, the architect said that building a new garage in back of the house, which also makes good sense, would be viable. He identified as a drawback to this plan that it would place the garage somewhat close to the pool. The architect also noted that the garage could reasonably be placed farther from the pool in the back. He noted that this could block the light from some windows. However, since that portion of the house is elevated from grade, using a flat roof garage rather than a gabled one would again be a viable, reasonable alterntive.

  4. There truly are alternatives available to help you fulfill your codified objectives as members of the BAR, which are to “preserve and promote the character and appearance of buildings within the Village of Scarsdale,” and “to ensure that buildings are designed in harmony with the neighboring community.” The character of the Autenrieth Road neighborhood is overwhelmingly defined by the gracious facades of historic homes whose garages are inconspicuously sited. Several of these homes have been purchased in recent years by new families with young children.

  1. A second key consideration, fervently expressed by neighbors, is that the siting of the garage and driveway, as proposed, will unambiguously cause tremendous stress on the centuries old, healthy, black oak tree in the front yard. The tons of fill required to change the grade to accommodate the proposed garage will prevent the needed oxygen from diffusing down to the roots. Even with the best of precations during construction, it very well may result in the oak’s death perhaps over the next 8 to 10 years rather than the hundred or more years it might otherwise live happily. Bill Logan, an expert arborist and professor who has written a book on oak trees, estimates that the tree is 275-325 years old. It certainly was growing robustly before the American Revolution. If it is as much 325 years old, it is remarkable to ponder that the tree was already growing on the land that Caleb Heathcote purchased in 1701, marking the Founding of Scarsdale. I have appended Mr. Logan’s consultative report, which outlines the specific measures necessary to make a good faith attempt to help the tree survive during and after construction. At a minimum, these measures should be made a condtion of approval of the application by the BAR and for permitting of any construction.

  2. Finally, as mentioned, the current investment group owners of 21 Autenrieth, who I understand do not live in Scarsdale, have no plans to live in this house. While I have respect for the rights of ownership, the reality is that they are simply looking to profit from a transaction. To me, it seems like they are looking at homes in Scarsdale as simply an asset class like a stock, a bond, or Bitcoin for that matter. To those of us who actually live on Autenrieth Road or all of you who live elsewhere in Scarsdale, our homes are not just a commodity. They are where we spend our lives, raise our kids, and grow old. They are an expression of who we are—and we are much more than Bitcoin!

  3. In closing, I will add that none of the neighbors have objected to the building of the substantial additional living area proposed for the side of the house. The house will likely sell for more than the investor group paid, and perhaps it will even command a better price if the garage is not occupying a portion of the front yard. While the investors have made a speculative investment and may or may not make a profit aaer expenses are factored in, this is true for any investment. Others involved with the applicant—builders, landscapers, realtors, architects, and others—are all likely to profit wherever the garage is sited. I also realize that this is the fourth time this project has been brought before you. That’s a lot, but several of those times was because the applicant had failed to provide adequate elevations or renderings to allow you, the BAR, to make a decision with the needed information. You, the members of the Board of Architectural Review know in your hearts and minds that the right thing to do is to site the garage elsewhere on the property. You have the power to do so, and I hope you will.

Thank you.

William G. Roberts 15 Autenrieth Road Scarsdale, NY 10583

Here are the comments of the arborist:
Dear Ms Roberts:

This letter comes to present my conclusions about tree protection for an upcoming construction project that is proposed in the vicinity of a very large mature black oak that measures approximately 57.5” diameter at breast height (DBH). I have reviewed the documents submitted to the Town of Scarsdale and posted on the town website under the 26th February architectural review tab. I also visited the site on 8 Janaury 2024 to examine the tree.

1. This oak is an extraordinary specimen, among the largest oaks in Westchester County. It is almost 5 feet in diameter at breast height (DBH). Such a tree represents an incalculable benefit, not only to the people who can see and interact with it daily, but also to the thousands of mammals, birds, insects, spiders, and other macroinvertibrates that live and/or feed on and in it, as well as to the billions of bacteria and fungi that inhabit it. It is part of the intact ecosystem that characterizes Scarsdale yards and gardens. Its loss would be very serious, not only aesthetically but also ecologically.

2. The tree is in very good condition for a tree of its age. Mr. Nestler suggests that it is roughly 85 years old. It is likely much older than that. Old-growth trees of comparable stature in the New York Botanical Garden have been cored and measured at 275-325 years old.

3. The tree shows little or no branch dieback, and past pruning wounds are closing very well. The tree’s form and its broad-reaching, open-grown branches suggest that with proper care, the tree can easily live for many more years or even centuries. Pre-construction pruning should be limited to the removal of dead, damaged, diseased or broken branches. No “compensatory pruning” should be done. (Mr. Nestler believes the tree to be a red oak. Regardless, there is no difference in treatment for either species, as both are common members of the red-oak group of oaks, both species preferring to grow in upland areas.)

4. Ideally, the construction should be kept back a radius equivalent to the Critical Root Zone (CRZ) of the tree. For a 57.5” DBH tree, the CRZ has a radius of roughly 58 feet. The CRZ represents an area within which the tree’s important roots are located, both roots that keep it standing and roots that absorb the water and nutrients that the tree needs for its life. No disturbance should occur around the entire circumference of the tree within a radius of 58 feet. In that case, the driveway could not be located as shown in the plans that I examined on the website.

5. Because this is an important and irreplaceable tree – by that I mean that a tree of this stature could not be replaced on the site with less than an eight-decade lag time – it is best if its entire Critical Root Zone is preserved, not truncated or buried under feet of fill soil. The Critical Root Zone is roughly comparable to the suggestion in the Storm Water and Erosion Control Plan that disturbance be kept back beyond the edge of any tree’s drip line. The drip line is the edge of the tree’s canopy around its entire circumference. In this case, the drip line is equal to or greater than the 58-foot radius suggested by the method I have used, which employes DBH to calculate the Critical Root Zone. It may be objected that the tree is located only 15 feet from the road on one side, but the fact that it did not have the ability to extend its roots in that direction is all the more reason that the root system will have thickly colonized the available soil on the other sides, where no obstruction exists.

6. When a tree is healthy and stable, and when the disturbance does not occur around 360 degrees of circumference, however, it is sometimes possible to come closer along a part of the circumference, perhaps as close as 5X DBH. Since the DBH of this tree is 57.5 inches, a limit of disturbance that kept at least 25 feet from the base of the tree might allow the tree to survive and thrive. Such an intrusion would place the tree under tremendous stress and should only be undertaken if a complete list of protection and remediation measures are instituted. Not one but all of the measures should be instituted.

7. These are the measures that should be used:

a. Prior to the beginning of any disturbance in the area, the arborist should meet with the construction and management team to review all
protection measures.

b. Because this is an important and irreplaceable tree, any penetration within the Critical Root Zone of the tree should be preceded by an Air Spade investigation. The Air Spade allows a trench to be dug using a supersonic air jet. This investigation will allow us to excavate along the line of proposed disturbance in a way that does no serious harm to the root system. Wherever significant roots are encountered, they can be properly pruned, before construction begins. This work must be performed by a certified arborist familiar with the use of the Air Spade.

c. The Tree Protection Zone – delineated by a chain-link fence – must encompass the entire portion of the Critical Root Zone that will not be impacted by the retaining wall and fill. Within this area, no storage or spillage of materials can occur. No waste or construction material may be placed. No machinery or vehicle may pass. No individuals may pass except as specified by the arborist. The entire Tree Protection Zone should be covered with a 3-inch layer of clean mulch, though a space of 6” radius at the tree’s root flare should be left free of mulch.

d. No construction, grade raising or retaining-wall building can occur within the Tree Protection Zone. . All the construction must be done from the area outside the protection fence. No debris or runoff from that process can be allowed within the protection fence.

e. Plans appear to indicate that the new driveway will require a retaining wall whose base is dug more than 2 feet below grade. Furthermore, the fill area to create the new driveway’s path appears to require between 3 and 6 feet of fill. The combination of the cutting needed for the retaining wall base and the deep fill will effectively mean that no existing roots beneath the wall or beneath the fill will survive. Even if the original soils are not compacted prior to placing the fill, the depth of the fill will prevent the existing roots from getting the oxygen that they need to respire.

f. It is therefore very important to institute a program to help with root zone remediation. A combination of root stimulants and Induced Systemic Resistance (ISR) materials should be applied over the entire preserved root zone three times during the next two growing seasons. In our work, we use Adam’s Earth as a root stimulant, and a combination of Green T Impulse, Polyphosphite 50 and Alpha/Omega as ISR materials. All are manufactured by The Plant Food Company (38 Hightstown-Cranbury Station Rd, Cranbury, NJ 08512).

g. No “compensatory pruning” of the tree should be performed, though dead, damaged, diseased and broken branches should be properly pruned.

h. It is important that no roots greater than 1” diameter be cut during installation of the irrigation system. It will be important for an arborist to be on site during that installation. Should larger roots be encountered, the system will need to be placed beneath the existing root zone in that area.

i. I understand that it has been argued that this tree can tolerate a great deal of fill soil near its base because an oak in an adjoining property has tolerated fill in the past. Please keep in mind, however, that the adjoining tree is a swamp white oak, which is tolerant of flood-plain conditions, which include inundation and the periodic transport of soil materials. A red or a black oak is an upland tree, much less tolerant of those conditions, so it should be given the maximum preserved root zone possible. Furthermore, the tree in question here is much older than adjoining swamp white oak.

j. The Storm Water and Erosion Control Plan indicates that the proposed location of the Construction Entrance lies in the front year within the Critical Root Zone of the tree. This entrance should be shifted so that it does not cover the Critical Root Zone.
Let me reiterate that this is a historic oak that is very important both aesthetically and ecologically to the town of Scarsdale. It is in my estimation well worth the effort needed to preserve it.

I am the founder of Urban Arborists, a New York City-based tree care firm that has been caring for many of the city’s great trees for more than three decades. I have been on the faculty of the New York Botanical Garden for most of that time and continue in that role. I am a Visiting Professor of Landscape Architecture at Pratt Institute. My books include Oak: The Frame of Civilization (New York: Norton), an examination of the relationship between people and oak trees.

Please feel free to call with questions and comments. My cell is 917-567-7215.

Urban Arborists, Inc.