Kaufman and Broad Home Corp. of Los Angeles posted its fourth consecutive year of record operating performance as net income rose by 20% for the year ended Nov. 30, 1986. Net income for the fourth quarter, typically the strongest for home-building operations, also increased. A spokesman said that the operating performance from home building alone reflected an even stronger trend. "Revenue from on-site housing rose 45% to a record $491.2 million, up from $338.7 million the prior year. Housing pretax income, excluding unconsolidated mortgage-banking operations, which had an unusually large $10.8-million gain from the bulk sale of loan servicing last year, rose by 31% to $48.3 million in fiscal 1986," the spokesman added.