You're very confused. You need to straighten out your thought processes before going any further.
1. If you want to just buy a house, you need to have savings. So if you want to buy a house for 100K, a Bank appears to be willing to lend you around 90K and therefore you need to have your own money of 10K. You would also need money for legal fees and basic furniture.
2. If you already own a site, then you are asking for a loan to build a property on that site. You have to be more specific with the bank when you ask how much the bank will lend you in these circumstances. You would need to have spoken to a builder or similar who can tell you the likely cost of building a house and then ask the bank if they will lend you that money. You already have the site and the bank will probably lend you a percentage of the cost of building the house, secured by way of a mortgage on the site, so you will still need savings.
mf