“In our case, the upper dweller would have to build a ma’akeh, since there is a safek d’oraysa,” added Rabbi Dayan. “Moreover, even if there is not an actual obligation of ma’akeh, the mitzvah is extended to remove any potential danger. [C.M. 426:7-8] However, if not a definitive mitzvah, there is no berachah on building the guardrail.”
“Our case is not exactly a renter,” noted Mr. Adler. “We agreed that Mr. Braun has ownership of the porch.”
“That is correct,” replied Rabbi Dayan. “Some contemporary authorities write that even if the renter is exempt, in our case – where the upper dweller has ownership of the roof porch – he is certainly obligated in ma’akeh, and needs to make a berachah.”
“Who would make a berachah, anyway, considering that the contractor is not Jewish?” asked Mr. Adler.
“That’s a separate issue,” concluded Rabbi Dayan. “Let’s leave that for our next discussion.”