The answer to this question depends largely on how long you believe you'll be holding onto the properties that you and your development firm are designing and building.
For example, if your plan is to sell commercial buildings as soon as possible, certain property and casualty provisions will likely become your buyers' responsibility before they can be yours. By contrast, you, unlike them, would need comprehensive builders risk coverage to account for potential mishaps during construction.
On the other end of the spectrum, if developing real estate for your own business use, it's in your best interest to protect it with insurance as wide-ranging as the risks your properties will face.