Where is it located? If you are also doing an addition you most likely need site plan approval that includes a civil engineer as well, which can run you several thousand dollars. I paid $10k for drawings to get through the permitting stage on a brand new home including the site/civil design and that was by far cheaper than others I talked with and I have been very pleased with who I used.

It depends on the property and situation, but I would say tear down once you are over $200k in costs. I would be careful on the pricing you see from the links above and some of the tract builders to build on your lot. I talked to them about building a home for me and the cost they quote you is like a car dealer. They hit you up for everything. For example, depending on jurisdiction they have to use a different strength concrete and charge extra etc. Just looking at the price you need to really see an apples to apples comparison. Plus you have to use their lender. Where is the property located?

I am in the construction business and also in the process of building a house for myself. I can share lots of advice related to the architect. I would make sure the contract has stipulations that they are responsible for all costs related to re-designs required by the county in order to obtain the permit. Also which permits are they helping you get? Depending on jurisdiction, you may need site development permit, HVAC permit etc. that all require drawings as well. Some architects do and some do not do this. I also had a clause the architect will respond to all contractor requests for information (ie. drawing clarifications/discrepencies) for no cost. Also, strongly recommend not hiring the architect for construction administration (overseeing construction). Send me a private message if you wish and I can send you more info and a draft of the contract (which was the contract I generated not one from the architect which is completely one sided in their favor)