You are welcomed. So now you should know where to look out for to negotiate. Most people would tend to negotiate on reducing the costing of the 13 items, for example, the price of the air-conditioner, by swapping one brand to another. Or by reconfiguring its capacity. But the total cost of the 13 items constitutes only about 25% of the building cost, so these items shouldn't be the focus. Moreover, these items have a great impact on how the building would eventually look. If you were to replace the marble with homogeneous tile for the living and dining area, the look and feel would be different? The $200,000 figure for the wet works for each storey is just a guesstimate, as I don't know the proposed architecture for your house, the build-in space for each storey etc. Just 4 years ago, you could get a pricing range of $90-$110 psf for the wet works, or $90,000-$110,000 for a space of 1000 sqf. Earlier last year, I heard that the pricing has gone to $150-$170 psf. And then it kept going up throughout the year. You could read the headline news today, on the higher labor cost impacting building contractors. Also, you could discover that contractors would price the wet work $psf higher for a terrace than a semi-d, for example, because most of them don't like to do a terrace. It is true that the building process is somewhat less effient for a terrace, being flanked by 2 neighbors. If the neighbors are nice, then they wouldn't mind the workers to step on their roofs occasionally. But some neighbors would mind, to the extent of calling in the police to complain of the infringement. (Be very friendly, and attentive, to your neighbors during the construction, ok?) Cheers!