I am currently on my last 3 month extension of my one year ed visa and am planning to get a new ed visa at a different school studying something different when my extension is up do I need to go to loas again to apply for a new ed visa or can my new school just extend my current ed visa for another year ? 

If attending a informal school (language studies for example) you have to get a new non-ed visa after the one year of total stay allowed which you are apparently attending since you have been getting 90 day extensions.