Hi all, I'm about to kick off design of my two lot development on the Gold Coast. This is my first time building and I sort of jumped in the deep end, the site is on a ~25% slope. I have a local mate that's going through his first development so I'm chatting with him, one thing he mentioned was to use an independent building designer, so you own the plans and can put them out to tender, this way you don't get locked into any one builder, and have them take you for a ride to screw town. The flip side of this is the independent designer you choose needs to be very good at pricing, other wise you can end up in a situation where you have been told you can build for $300k, spent 6k on plans, and all the tenders are coming back at $400k. You then need to go back and spend $100 p/h on amendments to get back within your original budget. How do experienced developers insure their designers are staying within budget on a custom build and avoid the above happening? One designer I've met with suggested he will go back and fourth to the builder and keep getting ballpark figures, for example in the concept stage, get it to within 50k of budget, then move forward again. This same designer I've now learned has blown out by over 30% on one of his slope designs last year. What sort of discrepancies should I be expecting from the budget my designer and I have agreed to, and the contract prices for the tender?