Rules Enforcement

I presume you are on the Architectural Committee and thus had the authority to disapprove that request stating the reason for denial was that it did not conform with the original style. I would have approved SUBJECT TO installation of a post light fixture of the original style to provide uniformity.

You need to develop and publish 'architectural guidelines' within the scope of your docs. authority.
If this is vague the HO MAY, MAY, MAY, have an 'opening' to force approval depending on your specifics and his desires.

Also at some point in time the exact style, etc. of lamp may no longer be available and alternate(s) must be defined.

See the statute below...

720.3035 Architectural control covenants; parcel owner improvements; rights and privileges.—
(1) The authority of an association or any architectural, construction improvement, or other such similar committee of an association to review and approve plans and specifications for the location, size, type, or appearance of any structure or other improvement on a parcel, or to enforce standards for the external appearance of any structure or improvement located on a parcel, shall be permitted only to the extent that the authority is specifically stated or reasonably inferred as to such location, size, type, or appearance in the declaration of covenants or other published guidelines and standards authorized by the declaration of covenants.
(2) If the declaration of covenants or other published guidelines and standards authorized by the declaration of covenants provides options for the use of material, the size of the structure or improvement, the design of the structure or improvement, or the location of the structure or improvement on the parcel, neither the association nor any architectural, construction improvement, or other such similar committee of the association shall restrict the right of a parcel owner to select from the options provided in the declaration of covenants or other published guidelines and standards authorized by the declaration of covenants.
(3) Unless otherwise specifically stated in the declaration of covenants or other published guidelines and standards authorized by the declaration of covenants, each parcel shall be deemed to have only one front for purposes of determining the required front setback even if the parcel is bounded by a roadway or other easement on more than one side. When the declaration of covenants or other published guidelines and standards authorized by the declaration of covenants do not provide for specific setback limitations, the applicable county or municipal setback limitations shall apply, and neither the association nor any architectural, construction improvement, or other such similar committee of the association shall enforce or attempt to enforce any setback limitation that is inconsistent with the applicable county or municipal standard or standards.
(4) Each parcel owner shall be entitled to the rights and privileges set forth in the declaration of covenants or other published guidelines and standards authorized by the declaration of covenants concerning the architectural use of the parcel, and the construction of permitted structures and improvements on the parcel and such rights and privileges shall not be unreasonably infringed upon or impaired by the association or any architectural, construction improvement, or other such similar committee of the association. If the association or any architectural, construction improvement, or other such similar committee of the association should unreasonably, knowingly, and willfully infringe upon or impair the rights and privileges set forth in the declaration of covenants or other published guidelines and standards authorized by the declaration of covenants, the adversely affected parcel owner shall be entitled to recover damages caused by such infringement or impairment, including any costs and reasonable attorney’s fees incurred in preserving or restoring the rights and privileges of the parcel owner set forth in the declaration of covenants or other published guidelines and standards authorized by the declaration of covenants.
(5) Neither the association nor any architectural, construction improvement, or other such similar committee of the association shall enforce any policy or restriction that is inconsistent with the rights and privileges of a parcel owner set forth in the declaration of covenants or other published guidelines and standards authorized by the declaration of covenants, whether uniformly applied or not. Neither the association nor any architectural, construction improvement, or other such similar committee of the association may rely upon a policy or restriction that is inconsistent with the declaration of covenants or other published guidelines and standards authorized by the declaration of covenants, whether uniformly applied or not, in defense of any action taken in the name of or on behalf of the association against a parcel owner.
History.—s. 11, ch. 2007-173.

Florida has tried to eliminate arbitrary or capricious behaviors in this area.
Thus the requirement to publish a guidelines document.

If the HOA has neglected to do so via ignorance or contempt then they have less authority to challenge future submissions.
Of course there are many factors to consider but this one is a foundational one.

Thanks everyone.