(Memo from Charles Prince, City Arborist, to the Planning Staff, Planning Commission)

Citing current zoning regulation for lot coverages for R-C, R-TH, and R-M districts, I recommend reducing building lot coverages for T-Zones to 55% by-right, 60% to 65% Special Use Permit (SUP), and 70% maximum lot coverage. The recommended coverage is greater than R-C (50% gross lot coverage), R-TH (up to 44%), and R-M (up to 50%). Often, tree canopy and stormwater devices cannot occupy the same areas without significant engineering or complex stormwater devices. Reducing the building lot and impervious surface lot maximums for T-Zones will reduce these conflicts from the conceptual stage of the project. Since the stormwater regulations have changed, there have been conflicts between the trees/stormwater facilities on single-family grading lots with a building lot coverage of 25% (35% total lot coverage) and a required tree canopy of 20%.

I support the increased setbacks, maximum heights by-right and SUP, and SUP step-back. The 20 feet setback in front and rear will provide sufficient growing space and allow the 15% tree canopy recommendation to thrive and provide functional tree canopy. I have concerns about the SUP allowance of 10 feet in the rear as this provides minimal growing space for the 15% minimum tree canopy required and will likely cause conflict between the tree canopy and the building may cause excessive pruning that can reduce the functionality of the tree canopy.

I fully support the 15% canopy minimum requirement for by-right and SUP T-Zone developments.

Ideally, residential and commercial uses in the T-Zones will be regulated as if they are zoned per their proposed use. This is likely to prevent unnecessary tree related fines for homeowners in T-Zones since trees are regulated on all zones except R-1A and R-1B.

For commercial uses, tree canopy only applies to the trees inside the subject property lines and not in the City’s right-of-way, this applies to required streetscapes. The Arborist Office and the Urban Forestry Commission (UFC) are working on changing current code and policy on future Special Exception (SE) and commercial projects. All trees will be regulated similar to site plan rules.
Residential properties can include trees in the right-of-way and must include a street tree every 25 feet where reasonable to provide a tree lined aesthetic for City streets. This is a current
requirement in the City’s Urban Forestry Grading Plan Guide, page 5. Trees on private property will not be regulated, trees on HOA or other community owned property will be regulated.

Overall, the recommendations provide space for functional tree canopy for by-right projects. A functional tree canopy provides many benefits for health of the occupants, energy use of the structure, value of the property and surrounding community, slow stormwater, and habitat and food for wildlife. Stronger consideration for the SUP coverages may be warranted to ensure we are not allowing monolithic type structures that do not permit a healthy tree canopy. Thank you to everyone’s work that has gone into T- Zones and I look forward to moving this forward.

(From the city document https://fallschurch-va.granicus.com/MetaViewer.php?view_id=2&clip_id=2267&meta_id=120982 )