I'd suggest to do it now. You'd have all the costs for the kitchen refurb works to give to your accountant and they'd know what to do with it. They'd also be able to scrap any depreciable items that were disposed as well by using the depreciation schedule.
I presume you bought it in May 2014 (not 2015). Yes you can use the Depreciation Schedule in the 2013/2014 FY tax return. You can also amend tax returns already completed for up to 2 years (noted in case you had already submitted your tax return for that FY).
