Size Up- Not just What it is but What it was

While out running errands I came across the building that is pictured below. From the street it looks like any other Starbucks, Moes, Cold Stone, Remax and dentist office. But a closer look reveals the old smoke stack and a 360 reveals that it used to be some type of plant or factory. This changes our size up completely. It takes the building from being a possible Type II to a Type III or Type IV. Meaning that instead of truss being our main concern, now it's hidden fire spread and the age of the building. Attention to detail and looking for clues can make our size ups much more effective. Keep in mind that what the building is now is important, but it's just as important to look for clues for what the building has been. Below is another picture that shows another common size up sight in my city but may not be so common to everyone. 

Pictures below is a picture of an SRO (single resident occupancy). The window is clearly boarded up from the inside because this house is cut into small 6'10' or smaller plywood rooms that are rented out individually. This is of course illegal but happens all the time. Finding a clue like this during a size up is going to make a huge difference for everyone. SRO's complicate all your operations from searching to advancing hoselines. It can be difficult to maneuver and stay oriented in a house split into SRO's. For a firefighter in an area where SRO's are not common their presence can really catch companies off guard and cause major problems for the operation. Being aware of out of the ordinary things during a size up can greatly help the entire operation.