I live on an estate with 9 unit holders bound by a common

Hi - I live on an estate with 9 unit holders bound by a common set of property deeds. One of my neighbours wants to remove a restrictive covenant that would then let him sell part of his garden for house building, which would have a detrimental impact on our estate. He says this can be done by a Deed of Variation which he says requires just a majority vote. I would have thought, as per a Deed of Variation for a Will, that all parties would need to agree, otherwise any majority of 5 unit holders could get together and change an aspect of the Deeds that is not in the interest of the other four. Can you advise?
JA: What steps have you taken so far? Have you prepared or filed any paperwork?
Customer: ? I have not taken any steps. The proponent of the change has called an EGM, where he wants a vote, without working through a lawyer, not has the management company requested any legal advice
JA: Where is the house located?
Customer: republic of Ireland
JA: Is there anything else the Lawyer should know before I connect you? Rest assured that they'll be able to help you.
Customer: This is the bare bones of it. I am trying to establish if a deed of variation to property deeds requires the agreement of all parties. From what I have read, this appears to be the case - in the UK I understand that if there are more than 8 unit holders and no more than 10% disagree, then it may be possible to proceed by applying for the variation through a first-tier tribunal, but I don’t know what the law is in Ireland