Our builder uses the std HIA contract. The are certain allowances associated with building an extra level under the house that are additioinal to the Base Price. I'm thinking brick, concrete and associated labour.
My problem is...I don't know what costs will be in the Base Price and which extra costs they can charge us for (and add their lovely 20% margin plus GST). The builder could potentially get a single invoice form a brickie and say "it's all for the underneath area" and make us pay for it. They may not be so underhand but they could allocate a percentagew which is not fair...it could all be quite opaque and up to the builder's opinion and I don't like that.
Any experiences and ideas?