Depends on what you are building, this is a house for the rest of our lives, its an expensive thing and most people try to get that number down, but if you think over the lifetime of the house it works out. A lot goes into a house and you need someone who is confident at doing it. It is stressful and it’s better to invest in the bones of the house. We still don’t have curtains, wardrobes, garage, landscaping, but all of that can be done later. We humans are visual creatures it’s hard to imagine what it’s like to live in a Passive House until you experience it.