Doug, the draw latches seem a good idea but I can't find any decent sized ones here but still looking. Maybe I could make something similar out of wood but bigger?
Charley, there's not too much I can change about the door, which is already up and running, so I can't implement any of the garage door ideas mate. But again its the holding firmly closed that's the problem.
Dan, the door probably weighs about 150lbs or 70kg so lifting from outside is not too bad even on my own. I did originally plan on using 2 linear actuator rams to open it but they take up too much valuable wall space so I ditched the idea and went for the low tech lifting method, me, and a leg to place under it when open, though I know this may not be so safe in windy conditions so I will have to rethink the support. I will never need to open the window more than about 45 degrees. PS the windows are large but made from twin wall polycarb so only weigh about as much as a pack of smokes! They do have wire mesh behind them though to deter the numerous thieves that are about nowadays.
Keep the ideas coming please Guys, Al