Yes, whatever you calculate the total construction costs to be, add 15-20% for contingencies, because they happen. And don't forget to research and include in the total costs all of the permits, fees and licenses which your local jurisdiction may charge.
Unfortunately, there are no "lists" that I have ever seen when it comes to the site selection, design and construction of a custom home. There are some generally common sequences:
--Site exploration and selection
--Exploration and selection of house design, fixtures and equipment, and preparation of necessary construction documents
--Bidding and award of construction contract (do your due diligence on the many types of construction contracts and select the one in your best interest)
--Construction (this always takes longer than anyone expects)
--Close out, substantial completion, occupancy and close out actions (touch up and fix up stuff)
One common approach to stipulate in your construction contract is for progress payments to be made upon a release of contractor's liens for the work for each progress payment (meaning all applicable sub contractors have been paid by the general cntractor, and to withhold 10% of each progress payment, to be paid in a final lump sum after all close out actions are completed by the builder.
Will you be using an architect or other design professional?
Q