I think that you would be able to build bricks to some extent, but they wouldn't compare to regular concrete or HSA biocomposites.

Feces aren't known for their binding properties and their compatibility with Martian dirt wouldn't be the same as with the dirt you see on Earth.

Also, shelters made of human or animal excrement are generally used to repel bugs or withstand heat waves. Colonies on Mars wouldn't have much use for that though!

Interesting question!