In software domain, what is the difference between Building Solution Architecture and Building Software Design? Is one of them replacing the other?

Nie ... Software Architecture is broader and abstract than Software Design...

Software Architecture is developed first and based on those building block and communication protocols, a software design is developed..

But they are close, Design related issues such as performance, conformance, API availability may refer to a bit reiteration of the Architecture...

Solution architecture includes hardware and software designs. 

Solution architecture is the first is derived from systems analysis.Intially system engineers develop the architecture of how the sytem will flow then desighn evolves from the intergrated form structure.