Our two story colonial has a one story addition wrapping around two sides of the house, with a slanted roof joining the wall of the original house. The roof on the addition has no ventilation, and no insulation above the ceiling.

Question 1: Should it be ventilated and/or insulated?

Question 2: If it should be ventilated, how should it be done? There are no soffits on the addition, so soffit vents are not an option. There's no ridge, so ridge vents are not possible. There is a small gable end at two ends of the addition, so small gable vents might be possible (but one of the ends is on the front of the house, so aesthetically it might not be good).

Question 3: If it should be insulated, how would you do it since there's no access?

The addition was put on the house in the 70's and there are no signs of water damage or other problems. But during the summer, we can feel the heat radiate through the ceiling inside of the house.