Mayor Bill de Blasio will unveil tomorrow a vision for fulfilling his biggest campaign promise -- creating or maintaining 200,000 affordable homes. It is a critical part of his plan to address inequality, but not all affordable housing is created equal.

Real success means making NYC a great place to live for people in all income levels. To achieve that, the plan will need to address:

What is "affordable"? Many developers declare a building to be "mixed-income" even when rents are too high for most New Yorkers. In many neighborhoods, like the South Bronx, incomes are much lower than the city average often used to define affordability. New housing must also be accessible to the poor and recently homeless families.

How long does affordability last? Too many affordable developments become market-rate 30 years after they are built. Partly because of that, NYC is facing a crisis trying to protect its affordable housing. De Blasio has wisely talked about making affordability permanent, but achieving that will mean new approaches to make it financially sustainable.

A common misconception about affordable housing is that it has to look and feel cheap. But good architecture and sustainable design shouldn't just be for the rich. After all, being green isn't about being chic -- it's about cutting waste and lowering living costs, critical for low-income families. Our Intervale Green building in the Bronx is the largest Energy Star-certified affordable housing development in the country. Along with others, these are models for affordable housing that should be applied citywide.

Finally, the housing plan needs to be about more than just housing -- it needs to be about creating safe, healthy, lasting communities. When residents have pride in their homes and neighborhoods, good things happen. That may start with great buildings, but it also means access to fresh food, diverse shopping, economic opportunity and culture. Instead of waiting for gentrification to bring the first cultural center or coffee shop, we should create them now for the people who need them now.

The mayor has an opportunity tomorrow to do all these things, and build the housing that leads to strong and healthy communities.