Supply is low in SoCal for entry-level homes.

We have the knowledge, resources, and time to do most light remodeling ourselves, but we also seem to be buying at a pretty bad time (low home supply in our general area). 

Is a HELOC a good choice in today's market with such few supply and greater demand. the buyers with cash offers are usually the winning bidsWould probably give you a quicker transaction and more leverage when negotiating The money is available only when you need it.It has great flexibility and light fees but can only do 20 year which makes payments higher and your cash flow per unit way lower. 

The basic theory of economics is supply and demand.

As long as supply doesn’t flood the market, expect prices to continue to maintain and increase.

The new NEC 2020 is out and it states (note that it is for "locations that are supplied by single-phase branch circuits rated 150 volts or less to ground are required to have GFCI protection for personnelYou have to check and see if your city/state require NEC 2017 or NEC 2020 or neither (like Phoenix AZ)  but it's good to follow the code anyway.2020 Edition: Section 210.8Dwelling Units 210.8(A)All 125- through 250-volt receptacles in the following locations that are supplied by single-phase branch circuits rated 150 volts or less to ground are required to have GFCI protection for personnel.Bathrooms210.8(A)(1)Garages and accessory buildings210.8(A)(2)Outdoors210.8(A)(3)Crawl Spaces210.8(A)(4)Basements (finished and unfinished)210.8(A)(5)Kitchens210.8(A)(6)Sinks210.8(A)(7)Boathouses210.8(A)(8)Bathtubs or shower stalls210.8(A)(9)Laundry Areas210.8(A)(10)Indoor damp and wet locations210.8(A)(11)Boat Hoist555.9Other Than Dwelling Units 210.8(B)All 125-volt through 250-volt receptacles supplied by single-phase branch circuits rated 150 volts or less to ground, 50 amperes or less, and all receptacles supplied by three-phase branch circuits rated 150 volts or less to ground, 100 amperes or less, installed in the following locations are required to have GFCI protection for personnel.Bathrooms210.8(B)(1)Kitchens or areas with sink and permanent provisions forfood preparation or cooking210.8(B)(2)Rooftops210.8(B)(3)Outdoors210.8(B)(4)Sinks210.8(B)(5)Indoor damp and wet locations210.8(B)(6)Locker rooms w/shower facilities210.8(B)(7)Garages and accessory buildings210.8(B)(8)Crawl spaces — at or below grade210.8(B)(9)Unfinished areas of basements210.8(B)(10)Laundry areas210.8(B)(11)Bathtubs and shower stalls210.8(B)(12)Both Dwelling and Other Than Dwelling UnitsCrawl Space Lighting Outlets210.8(C)Specific Appliances210.8(D)Equipment Requiring Servicing210.8(E) [210.63)Outdoor Outlets210.8(F)Sump Pumps422.5(A)(6)Dishwashers422.5(A)(7)Swimming Pools and Similar Inst.See Article 680* Other GFCI requirements scattered throughout the NEC.

As a busy agent, this was one of the major hurdles I had to overcome as real estate is a 24/7/365 sport, and sometimes I need help for those times when I am not available!

- Best construction loans, or lines of credit for materials/supplies (i.e.: Home Depot Credit Card) available? 

It really depends on the market and the supply and demand in the market.

Can you supply the form you send if you get that for?