Flooring in an investment property is often overlooked by the purchaser, this is even a large cost to replace the flooring when the rental period is up. We always suggest the use of tiles to all main areas and carpet to the bedrooms. Reason being if you install timber flooring the chance of it needing replacement are far greater with timber than tiled floors. 

It's an extra cost at the build stage, but money well spent in my opinion. The extra cost would be around $1800 for an average 18 square home for ceramic tiles and porcelain tiles would be around $2800.