Buildering (also known as edificeering, urban climbing, structuring, skywalking, boulding, or stegophily) describes the act of climbing on the outside of buildings and other artificial structures. The word "buildering", sometimes misspelled bildering, combines the word building with the climbing term bouldering. If done without ropes or protection far off the ground, buildering is extremely dangerous. It is often practiced outside legal bounds, and is thus practiced mostly at night.

Night climbing is a particular branch of buildering which has been practiced for many years in a variety of locations, especially at the Universities of Oxford and Cambridge, England. Night climbing, as distinct from buildering, is performed mainly by undergraduates under cover of darkness. The term "night climbing" has replaced the older term "roof climbing". The philosophy behind night climbing has undergone great change during the 21st century, with urban disciplines such as parkour having a heavy influence on the evolution of night climbing techniques and movements.

Adepts of buildering who are seen climbing on buildings without authorization are regularly met by police forces upon completing their exploit. Spectacular acts of buildering, such as free soloing skyscrapers, are usually accomplished by lone, experienced climbers, sometimes attracting large crowds of passers-by and media attention. These remain relatively rare.

Buildering can also take a form more akin to bouldering, which tends towards ascending or traversing shorter sections of buildings and structures. While still generally frowned upon by property owners, some, such as the University of Colorado at Boulder and Tufts University, turn a blind eye towards the practice in many locations.

Although often practised as a solo sport, buildering has also become a popular group activity. As in more traditional rock climbing, routes are established and graded for difficulty.