One condo at a time. I am consulting on a 2 unit renovation and this is an opportunity to set a mindful standard for sustainability practices in this building. I've always liked this building and hope to make the most of it.
There is a lot that can be done, even with a central plant for heating and cooling. IEQ issues, material and resource choices, universal design, recycling and more can be a significant part of a project such as this.