.....However, going by a rate by area seems very unfair to people with large spaces. Most costs other than the electric(with AC) are fixed and you aren't getting electric.
Yes, but this is not unusual. Article 4 of the Condominium Law says:
"Article 4.- Unless otherwise provided, each unit owner, for the enjoyment of his/her exclusive property, may use freely the common areas and facilities in accordance with their intended purpose, without hindering or encroaching upon the lawful rights of the other unit owners. He or she shall be obligated to contribute proportionately to the expenses of conservation, maintenance, repair and administration of the common areas and facilities.
"Except if otherwise agreed, such contribution shall be proportionate to the value of the divisible fractions of the building, taking into account their extension and situation. The percentage fixed in the bylaws, which should be registered upon submitting the property to the provisions of this law, may be modified only by unanimous agreement of all those concerned."
Because this language is in the law, similar language is very often used by the condo developer in writing the first bylaws that must be submitted, along with other documents, to get the property declared a condominium. The only way this can e changed is to have a unanimous agreement of the owners.
In the condo where I live, we had no difficulty getting this changed because the difference in size between apartments was only 15 sq mts. But in condos where, for example, you have pent houses at the top and efficiency apartments on the ground floor, it is impossible for me to believe that the bottom floor owners would agree to subsidize the rich folks on the top floor.
If there is a formula in the bylaws that bases maintenance fees on square meters, I think the OP is stuck with whatever figure has been agreed for apartments the size of his.
But my layman's opinion is that they cannot now punish him for a mistake they made by charging him more than what he is required to pay by the wording of the bylaws. I'll be very surprised if the lawyer doesn't say the same in the letter he will write on behalf of the OP to the Condo powers to be.
Also, if any part of whatever formula that is in the bylaws is different today than it was when the bylaws were registered, then the OP should have a check of the minutes to be sure the change was approved unanimously and not just by a majority of those present and voting.
What he needs is a lawyer experienced in condo law, not just a lawyer. You wouldn't go to a general practitioner if you needed
a hip replacement and you shouldn't go to a general lawyer if you have a problem that requires help of someone who knows the condo law and has experience taking matters to the Land Court (the court that deals with violations of the Condo Law) in matters related to the interpretation and administration of the condo law.
Now that this is in play, he may also want to raise the issue of apartments that increased in size and may not have had their fees raised. But if he does this, I think it would be best to do it in discussion with the administration of the condo so as to put some pressure on them to be reasonable in his case (assuming maintenance fees wee not raised in every case where they should have been) rather than in a public statement within the condo. I would not want to read on this board that the OP was found dead outside the condo, apparently having been thrown off the roof or out of the window of one of the enlarged apartments.