The 280-hour flight instructor was providing a 137-hour private pilot instruction in a weight-shift experimental light sport aircraft so he could obtain a sport pilot rating. The instructor said that they were both at the control bar as the pilot was practicing a normal approach to land. However, when the airplane was about 50 feet above the ground, the wind started to push the airplane to the left of the centerline. The pilot was unable to get the airplane back on course with the runway and the instructor attempted to take over the controls. There was not a positive exchange of controls and the airplane drifted further to the left and rapidly approached power lines, buildings, and trees. The instructor realized that they would be unable to out climb these obstacles and elected to fly the airplane onto the ground under the power lines. The airplane subsequently collided with a mailbox and a hangar resulting in substantial damage to the airplane's wing. The buggy, a landing gear strut, the propeller, and windshield were also damaged. The pilot reported there were no mechanical deficiencies with the airplane or the engine. The instructor stated that once the airplane started drifting off centerline, the landing should have been aborted and a go-around executed.