unitowner1 – the tiling work involved would be regarded as a change to the Common Property (floor) of the balcony, and as such and in the absence of an existing Special By-Law covering the conditions under which that type of work may be undertaken by Owners, consent cannot be granted by your Executive Committee (E/C) or unilaterally by its Chairman.
The correct procedure is for the Owners Corporation (O/C) to consider the past works by other Owner/s retrospectively and together with yours at a General Meeting, where a special resolution would needed to grant consent, and to set out the conditions applicable to future works such as but not limited to work times, noise, disposal of residues, waterproofing, and contractors’ licenses and liability insurance.
Then, and only if the O/C wishes with Owners’ consent to make them individually responsible for the on-going maintenance of their tiles, the wording of a Special By-Law (SBL) would need to be decided upon in the same way and be then properly Registered on the Title for the Strata Plan.
It’s entirely appropriate for that SBL to be drafted by the E/C and be then put to a General Meeting as you suggest, and in the circumstances it would be appropriate in my opinion for the O/C to cover the costs of that SBL as it would cover existing works and those which may be proposed in future, and enable those future consents to be granted by the E/C in accordance with its conditions (i.e. no General Meeting necessary).