No nonconforming building which was erected pursuant to and in conformity with the Zoning Ordinance shall be enlarged or altered in a manner which would increase the degree of nonconformity without a variance. Where the owner of a nonconforming building as stated herein seeks a building permit which will enlarge or alter the building but not increase the degree of nonconformity, plans for the proposed enlargement or alteration shall be provided to the Zoning Officer, who shall issue a certificate that the proposed enlargement or alteration will not increase the degree of nonconformity. If the Zoning Officer finds that the enlargement or alteration will increase the degree of nonconformity, he shall issue a certificate so stating, and no building permit shall then be issued without prior approval by the Zoning Board of Adjustment or the Planning Board of the Borough of Barnegat Light, in the appropriate case.