Developer Howard Hughes Corporation asked the Hawaii Community Development Authority if it can satisfy affordable-housing rules by making rental units available to moderate-income households, for twice as long as required, in return for building half as many affordable units. The developer submitted a petition to the HCDA Thursday. It wants to know if it can build less than 20 percent affordable rental units if it keeps the units affordable for 30 years. HCDA is scheduled to discuss and decide on the rule clarification request at a meeting Wednesday.