Ah yes, this is not the most common meaning of "depuis". Generally, it is about time, but here it can be about space.
You can have "je marche de ma maison..." only if you add the destination: "je marche de ma maison jusqu'à (or "vers") la gare". "Depuis" works with or without the destination.
"I walk from my house to the station". I walk starting from my house, not I walk in the direction away from my house.
Would a french speaking person not understand me if i said "Je marche de ma maison"?
Hi Colette, so just to clarify, are you responding along with Sitesurf to the question from CarlErb, above?
Would it be correct to say "Je vais depuis ma maison" if I wanted to say that I was going TO somewhere from my house?
No it is not correct because "aller" needs a destination: "je vais depuis ma maison jusqu'à..." with the destination would be correct.
I thought depuis puts the english sentence into progressive tense.. I have been walking from my house?
You are right, but only when "depuis" is temporal. In this case "depuis ma maison" is spatial.
I'm guessing in English we have adopted 'depuis' and retranslated it when we say, for example, - "I have been walking since I left my house." Not relevant, but interesting.