The National Park Service's official advice on preserving and restoring historic buildings.

Provides guidance to owners, architects, and developers of historic buildings with information on: cleaning and waterproof coating for historic masonry; repointing mortar joints; conserving energy; roofing for historic buildings; historic adobe buildings; dangers of abrasive cleaning; historic glazed architectural terra-cotta; aluminum and vinyl siding on wood frame buildings; repairing historic wooden windows; exterior paint problems on historic woodwork; and rehabilitating historic storefronts.