Software Design versus Software Architecture. What is the difference?

For the longest time I thought I understood the difference between Software Design and Software Architecture. 

I was always referencing the field of Architecture, in which you can design a home and you can architect a home. 
In this case, architecture is the larger of the two.  Design is usually just part of Architecture. 

But recently I got totally confused when I had a chat with my (very smart) project manager. 
Can anyone shed light on this in the context of Software?