This is all just hubris. There are many hundreds of large buildings like this, including most town halls, museums etc. which are about the same age. Are we going to gut all of these and have years of "refurbishment and modernisation"? I don't think so.....MP's are going to do this because they can.
Lesser mortals have something called "maintenance" and those having to plan and work around it have Hobsons Choice - rightly.
When you reckon up the few days per year in which the place actually works it could be reconditioned piecemeal without too much problem,
but these folk are far too important for that, they want to deal in big numbers!