A tax deduction applies to expenses necessarily incurred in earning your income.
My guess would be that you demolished your PPOR.
It is no longer your IP therefore the demolition had no connection with earning money from it as an IP.
Even as an offset against the proportion of capital gains tax payable when you sell,
I'd say it would be considered after the period of when it was used as an IP.
There are tax experts here who hopefully have the answer you'd prefer, but I wouldn't have considered it as a deductible expense.
Were there no salvaged items to offset the demo costs?
I asked for some demo quotes once and found a company willing to do it for no cash and full rights to all salvaged items.
Although it was in the late 80's (the Federation Green/Cream Years) and archi-antiques seemed much more sought out back then.
Cheers,
Beef.