Sacramento architecture can and should be designed for the city's climate, architect and green builder Matthew Piner said Wednesday. With its temperate Mediterranean climate, Sacramento usually experiences hot, dry summers and mild, wet winters. Its location on two rivers in a valley between the Sierra Nevada mountains and the Pacific Ocean contributes delta breezes to cool off most summer nights, he said at a monthly architectural design forum, Design Dialogue, sponsored by the Urban Design Alliance of Sacramento. Builders here — the same as builders throughout the world — once worked with Sacramento's natural climate to keep people comfortable when they sought shelter inside houses and