Oyinade Akanbi, architect from Lagos, Nigeria.I have interest in real estate investment and development. 

Do you plan to work as an architect and invest part time to start?

@Lekan King yes @Eric Greenberg gave you the correct info. 3+ units is considered commercial in Philly and you need commercial permits, which generally requires architect drawings and building plans, even for cosmetic work.

This hands on experience is invaluable when it comes to hiring people and writing and understanding a scope of work.As for college it's up to you, the best architect I know worked his way through college in the trades.

Im sure I can organise this through an architect office, but was hoping to find a cheaper deal.

Without any issues, it could theoretically go through the building and planning departments in 6-8 months with a good architect, but with issues (like difficult neighbors), it could be delayed over and over somewhat indefinitely.

Can you folks share your designer/architects, contractors ?

Do you want to own an architect firm?

as an architect who works primarily with homeowners, i will echo some of the others - that construction is not for the faint of heart, but if you make up your mind to do it, you can. 

A good architect can help you out a lot here.