Historic buildings are important to conserve for several reasons. They provide evidence of how past societies lived and allow us to understand architectural styles and construction methods over time. When built, builders considered factors like the durability, appearance, and purpose of materials like stone and timber. However, buildings decay over time due to issues like poor construction, inappropriate repairs, environmental exposure, and neglect. Proper conservation philosophies focus on preventative maintenance, understanding the building fully before intervening minimally, preserving historic evidence, and using responsible repair methods and appropriate materials.