Purchase mixed-use building with a partner in San Francisco

[Filomena Bettencourt]

Hi BP! This is my first first post ;) I'll try to keep this short. Keep in mind I'm a newbie to real estate!

I have a small business (hair salon) that resides in a mixed use building. 1 empty residential on top /1 commercial business on ground level (no garage). The upstairs unit is a 3bdrm/1bth, approx. 1500 sq ft w/ a back yard. 

The landlords acquired the building as an inheritance. As a stipulation to their inheritance their mother had to live in the upstairs until her passing; their mother just passed away. They want to sell and offered me first right of refusal. It's off-market and they have 2 other interested buyers. I'd love to purchase the building; unfortunately I can't do it on my own. I need a partner to help with the down payment.

I've already started a conversation and started the initial process (giving personal financials) with a commercial lending  bank, we'd be securing a 504 SBA loan. My CPA has been a great resource. I also had a 30min consult with a real estate lawyer. 

Do you think it's a good investment in partnering with someone that would like to purchase the building with me; they would reside in the upstairs unit and I would occupy the commercial space? If we partner,  would it be wise to separate the building into 1 condo and 1 commercial space later down the road? As a business owner, I want to secure my lease/rent. However, do you think this could be clouding my desire to purchase the building? What am I not seeing/asking?

Thank you!