I have a neighbor across the street who is licensed and does general construction and fine carpentry and another neighbor from a different place who is an architect (not sure if licensed or not).

My loan rate on an investment property is 3.5% and after construction there is a significant equity, which I prefer to use for HELOC.

How difficult would it be to get an invester friendly construction loan to build on a property where I live and have mortgage.

I am new to real estate investing and was looking into taking a heloc on my primary to purchase land and do a construction loan.

With new construction, comes more competition.

I do and I can say it has great potential for new construction and existing properties.

Purchase price: $540,000 Cash invested: $108,000 Investing in South Texas offers additional benefits:•Affordability: The price per square foot for new construction in South Texas is among the lowest in the country, making it an excellent value for investors seeking high-quality properties at a reasonable cost.

This is commonly called a reverse exchange or a construction or improvement exchange. 

Including acquisition and construction ? 

A common issue is supply and demand effected by population changes, construction, economic issues, the job market and location.Personally I haven't seen vacancy issues at this time,  but I have gone through cycles of vacancy issues.