A common misconception is that green/sustainable building costs more. In reality, sustainable building can actually save you thousands of dollars on energy and water bills, as well as cost of labor. For example, if you were to build your house using SIPs (structural insulated panels, prefabricated in a factory), construction time is reduced by 55% when compared to typical stud framing, which therefore reduces the cost of labor. SIPs also have an excellent insulation value, helping to reduce heating costs during the cold months.
There are countless materials and chemicals used in everyday construction that are detrimental to human health. From PVC (polyvinyl chloride) in our pipes to arsenic in our wood treatments, we are constantly inundated with harmful materials. I would highly recommend taking a look at the Living Future Institute's "Red List" materials, as it provides a great insight into what to look out for as well as some case studies: https://living-future.org/declare/declare-about/red-list/
This is obvious, but important none the less! As our population increases, sustainability is becoming a crucial factor in how we design to avoid wrecking the environment we all adore here in the pacific northwest. While many people think this places restrictions on how we build, it actually provides more room for innovation in materials, building techniques, and creativity.