HELP. Subdividing my property and building a duplex on it.

[Jacob Ortiz]

Hey BP community I need your Help & Input  please . 

       I want to take advantage of the new Senate Bill 9 (SB9) in California . With SB9 Cities must allow up to two lots (and up to four homes total) within single-family residential zones without any discretionary review as long as your property . Every city in California is handling this new legislation differently and have their own procedures . Here is the city of riversides FAQ for anyone who wants general information about SB9. 

 SB9 Riverside FAQ's

SB9 Lot Configurations 

      I am a fairly new investor . I currently own a 2 unit property in Riverside, California . The lot is .53 acres and 60% of the land is vacant and the other 40% already has 2 units on it so this is perfect for a lot split . I have already talked to the city planning department and they were extremely helpful . My property passes their pre-clearance and looks like I will be able to perform the subdivision under SB9  . I figure I already own the land why not build on it if the numbers make sense . The plan is to perform an "Urban Lot Split" , subdivide the property 60%-40% and build a Duplex on the new parcel since I will be able to get another address and separate utilities. I am currently talking to a residential land surveyor to  work on a site survey and Parcel Map proposal for me ,  up to the Tentative Parcel Map Approval. 

Here is where I need help . I really need to get an estimate on what it would cost to build a duplex on my property. I have the funds to perform the urban lot split and pay an architect for plans . To finance building the project Ive talked to a couple Hard Money lenders and thinking about doing a second mortgage on the property . Thoughts ? The property is worth around $570k right now and I owe $415K . My estimated ARV with adding the duplex should be 1.2million. Is leveraging my original property to fund building a duplex on the new separate parcel a smart idea?

What do you guys think of this plan ? Open to all ideas . Also just curious if you guys want to follow me along my project I will keep posting along the way .