The fact about land equity is that once you buy the land (let's say it cost $400,000), after that it could cost more and the difference between the second value (if it's bigger, of course) and the first value is the equity - if you have the first value taken using a bank loan for land. In this case, meaning that the land price has improved, you could get a land equity loan, get the money and make some other stuff with them - basicaly, you could use those money to pay your debts or any other problems and to lower your interest rate. The fact is that if you're starting a construction on it, to be sure if you have the money to pay whole construction and also to have to give the money back - there are desperate time when you have an urge need to pay your debts and you don't have the money to do it because you're building the house. The only option is to sell the house, unfinished and to get the money to pay. 

   The appraised land value is the second land price that is given after a period, most likely a couple of years, basicaly in this period the land prices could go low and you may not have the deal to get a land equity loan, but this does not mean you have to try your chances. You also have to know that a home equity loan is going to come to you with a fixed interest price, so don't worry to much about it. In the case of home equity line of credit, you may have variable interest, but initial interest is going to be bigger.

   In the case you get online to apply to home/land equity loans, then you have to be sure you compare them all and research in order to get the cheapest online land equity loan available down there - there is an cyber competition between sub prime lenders and personal loans, so you may have a chance to get new comers that are reliable and have smaller interest rate for marketing.

   In the case your land gains money over time, you could cash out the equity loan in order to have the money to buy a house - an equity is just another type of loan, money that you're going to have to give back monthly. If you don't just have the money it's better to get another job and get money from family and/or friends and not get the money with variable interest rates, because you could pay a lot and loose your land, in the end, thing that you don't really want. In the case you have a very bad credit, you could get a land equity loan, but you have to be careful what you do in order not to get any scams - be careful and play it right.