WHAT CAN I BUILD?

The answer to this question is divided into two parts; new or enlarged structures and existing structures to remain.

New or enlarged structures are subject to local zoning parameters like size, setbacks and uses.  These requirements are spelled out in each jurisdiction and can be available online or in person.  In urban or high-density building sites the zoning description usually is maximized by these limitations & you’ll have to design inside this “described box”.  Sometimes the “described box” is the design itself.  High land values dictate maximizing the design, but not always, as very high cash return stores or restaurants may justify a significantly under-designed structure to accommodate required onsite parking or landscaping.

Existing structures are usually only subject to local ordinances or zoning regulations regarding “uses”.  This can still affect things like car parking and truck loading requirements which may be likewise mandated.  This could mean that the existing structure be partially demolished to balance things like required parking etc. unless the use is existing and maintained without change.  Most jurisdictions allow for any previously approved use or structure to be maintained unchanged in perpetuity.