my name is erin carson and i'm the construction representative for the mayor's office of housing and community development. and i appreciate you taking the time to talk about this. i think you all basically talked about the same things i was going to bring up. including the density bonus, the cost of doing housing in san francisco. the importance of affordable housing. the crisis that we are facing right now. and yes, it all comes together in one sort of confluence of challenges. we have green roof requirements. we have open space requirements. we have housing requirements. we have the cost of building. and of course, yes, we can't afford to do high-rise construction, it never pencils out in the types of projects that we do. we have very constrained sites. our sites are usually challenging in ways others aren't even challenged by, we are on top of b.a.r.t. stations, on top of muni stations, all sorts of crazy things. so to add cost or remove units is a very serious issue for us. so you all understand these issues very well. i'm not telling you anything you don't already know. i appre