$($a$)$ Assuming that the basement in Question $18\mathrm{.}4($a$)$ is a simple rectangle in plan with few

openings and pipe penetrations, which waterproofing system would you recommend for the

walls? Give reasons for your choice.

$($b$)$ If the basement consists of a complex geometry with several corners, protrusions, and

penetrations, would your recommendation change? Explain.