On February 16, 1996, at 1740 hours Pacific standard time, a Rockwell 112B, N1233J, sustained substantial damage during a rejected takeoff at Sunset Sky Ranch, Elk Grove, California. The aircraft was owned and operated by the pilot and was on a personal cross-country flight. Visual meteorological conditions prevailed at the time and no flight plan was filed. The private pilot and two passengers were not injured. The flight was originating at the time as a cross-country flight to San Diego, California. The pilot reported that he initiated a takeoff with 20 degrees of flaps and rotated at what he felt was the normal speed. As the aircraft climbed about 20 feet, the stall warning horn went off and the aircraft ceased climbing. Buildings are at the departure end of the runway and the pilot believed he would strike them so he elected to abort the takeoff. Insufficient runway remained to stop the aircraft before hitting the buildings and the pilot intentionally turned the aircraft off the runway and into a muddy area, collapsing the nose gear. The pilot said he believes he encountered a wind shear induced by the buildings which are in close proximity to the runway. The FAA approved flight manual for the aircraft was examined. While the performance section of the manual contains a chart for a flaps 20 obstacle clearance takeoff, all references in the normal procedures and checklist portions of the manual are for flaps 10 takeoffs. Using the estimated temperature and pressure altitude at the time of the accident, the flaps 20 takeoff chart shows that the aircraft would require 1,600 feet to achieve a 50-foot altitude. The landing distance chart from a 50-foot altitude (at full flaps) shows a minimum required distance of 1,200 feet. The runway is 2,700 feet in length.