Unless the Committee can produce a soundly based legal opinion to the contrary, you can take their view as incorrect. An owner voting against such a measure would not be liable, that is just nonsense.
There are many buildings out there that do not comply with the current Building Code – that is inevitable because the Building Code has changed in many respects over the years. An obligation to bring an element of a building up to Code usually arises where work is done which involves a change to the specific element of the building where it may not comply with the Code. For example, a few years ago we had to replace the back stairs of our building, and to the extent that it was possible, the replacement stairs had to comply with the current Code.
It may also arise where an expert gives an opinion that that part of the common property is a safety risk, but you could challenge that.
There have been a few cases on this type of issue, have a look at this one which is on point – and it may be worthwhile you reminding the Committee that the work they want to carry out is in all likelihood an upgrade, requiring a special resolution of the OC.
http://lawyerschambers.com.au/balustrades-and-bca-requirements-when-repair-becomes-upgrade/