Did you buy the property as a completed premises or did you organise the renovations/refurb yourself?
If you bought the property as a finished property, then the selling agent should have organised a tax certificate giving the tax allowance on that site. The developers accountant will have produced this and normally, once the sale is closed the developers accountant will register this with the revenue. The developer will already have submitted the renovation/construction costs through his accountant.
What you get should just be a percentage figure which is the amount of the purchase price that you can offset against tax.