In my research into my San Leandro developer/mayor Earl Derry ( Derry, Weaver & Derry / Derry Bros.)  I have discovered that in several tracts they constructed that they have used architect Irwin Johnson.  It appears that Johnson was the architect who did most of their ranch house designs.

I think that the relationship between Derry and Johnson began with the "Broadmoor Park" tract.  This tract was started off in the late 1920s by developer EB Fields and sold off to the Derrys for completion.

As you may know Irwin Johnson and EB Fields collaborated hugely on Sheffield village.  I have found evidence of Johnson and Derry in the "Lealand Heights", "New Broadmoor" and "Broadmoor Park" all by Derry, Weaver & Derry or Derry Brothers.

• Lealand Heights:  Parker, Sandelin, Norene, Rantoul, Graff, East Juana
• New Broadmoor: Superior Avenue (new), Dutton, Glen, Oakes and Begier.
• Broadmoor Park:  Lee, Arbor, Glen, Oakes, Begier, Pala and Haas.