I am involved in a project in which I have been required(by municipal agency) to employ the trunk formula method to determine the value of trees on the property. The owner wants to develope the property and wishes to remove 2 trees to make way for building sites.If I add up the values for all the trees on the site the sum far exceeds what was paid for the property
It is my understanding the trees can comprise up to 20% of the overall value of a property. There are 18 trees on the property. The appraised value for the two trees to be removed is greater than 20% of the value of the property. The property owner will be required to mitigate the value of the trees that are removed.
When we are told that appraisals should be realistic and fair is there any way to figure the 20% total property value into the appraised value? Is this 20% figure valid? What is fair? What is realistic.

Mark, your situation is not all that unusual. The simple answer is “it depends.”

When developing your opinion of value, you have to consider many things. Your question revolves around reasonableness. You have to look at the use and purpose of the appraisal.

If Trunk Formula method is mandated, then you have the depreciation factors and the replacement tree cost to work with. Have you used a proper cost factor? Many Regional Plant Appraisal Committees (including the (Western Chapter ISA) have published cost guidelines.

Review your depreciation factors again. Are they appropriate for the circumstances. Have you depreciated for the location before or after the proposed construction? In cases like this, I would use the ‘before’ location rating, since that is what the municipality is “losing.”

As to landscape percentages, you’ll have to find and read those studies of landscape surveys. Or you can get in touch with a local real estate appraiser and ask for sales comparables between similar properties, one with good landscaping, one with more or less no landcaping. This will give you the percentage of the property appraised value that landscape contributes.

Be careful of applying a percentage to the landscape, such as the 20% you mentioned. The local percentages could be quite different from that. Most studies that have dealt with this offer ranges.

Now, as to the relationship between the value of 2 trees appraised by Trunk Formula to the value of the property, you have to look back to your assignment, and perhaps ask for clarification from the agency. Some US courts have made awards for trees that have been more than the total appraised property value, but those are often situations involving trespass or wrongful taking. For your purposes, the method is already determined, and it seems like the agency wants it applied regardless of how it compares to property value.


If you wish to contact me for more on this, send to
r carlson AT tree-tech DOT com
in typical email format without the spaces.