The local preservation committee may end up determining the extent of improvements to historic properties in the neighborhood. Living in an historic district can mean homeowners are required to practice extra caution and abide by mandated codes and building requirements. Consider the quality, design, materials, and craftsmanship of the original house as well as the changes that have occurred over time. Compatible interior and exterior changes of the same or better quality than the original house, even if done in different styles or materials, should probably be kept and restored. Be sure to remove any poorly designed or executed changes.

https://www.nps.gov/tps/standards/four-treatments/standguide/index.htm