. >> lawrence cornfield with the department of building inspection. the planning department is often faced with people building without permits. it is a real problem. our building permits typically say what is the legally proposed use so we can clarify that in the permit text itself. we try to address that to legalize some things. it is a problem with this intermediate step. things tend to get lost. similarly, we get plans, both from the planning department for their various review, as well as the building department permit review sets, where we have to rely on the permit applicants and their agents for preparation. we do not go out and verify the height of the building, the lot lines, and the way it is drawn. we take their licensed professional plant at face of you. when we go up to do inspections, which similarly do not verify all of these many dimensions. we look at the construction and has been proposed and approved and make sure it is built the way it was supposed to be built. it is unfortunate when there are errors or omissions. we are not measu

and i'm chief building inspect, lawrence cornfield. we have a bunch of slides we're going to go through today that i hope will give us sort of a basis to ask questions and focus our discussion. most of the decks that we see that we're going to talk about are made of wood. san francisco is a city built primarily of wood, in fact. and for better or for worse, it used to be wood was cheap and readily available and now, wood is expensive and you know, sometimes it's not even appropriate green material anymore. in fact, steel is preferred for a lot of uses because it can be recycled and reused. especially really good redwood and stuff that used to be used for exterior decks is almost unavailable but it's extremely political lynn i correct to use this clear redwood. now there's other materials including metal and other kinds of fabricated lumber that's kind of glued up. and you lee a lot of it. >> it's different types of pressure treated. >> so what used to be used almost exclusively is redwood in our area. and you still see huge amounts of