chesswood – unless your Plan has a properly registered special by-law that requires all Owners to maintain plantings within the cubic air space of their Lots, then its Executive Committee (E/C) has no authority to require you or any other Owner to remove their plants.
It’s impractical for an Owner to ensure that below-ground parts of any plantings remain withing the cubic air space of their Lot, but the established principle that applies to any necessary trimming of above-ground parts is that the Owners Corporation (O/C) arranges for the work and pays a proportionate share of the cost involved, as calculated from the plant’s overall height and that part that’s above the cubic air space of the Lot concerned.
As an example, the costs trimming of a tree within your Lot with a 4.4m high canopy would be split 50:50 between you and your O/C.
That said, it would be ill-advised in my opinion for any Owner to plant anything that could at some future time contribute to or cause damage to their property or to that for which the Owners Corporation is responsible, so perhaps make your E/C an offer whereby you’ll trim plantings to below the upper limit of your Lot’s cubic air space where that won’t adversely affect their appearance or stability, and that you’ll accept a negotiated application when necessary of the established principle that I’ve mentioned to any that remain.
Regarding the N.C.A.T., I’m not sure that Adjudicators favour either party, but rather their decisions seem to depend upon at which one their spinning chocolate-wheel stops
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