verb

umbauen

remodel · convert

Etwas so verändern, dass es danach anders aussieht oder anders genutzt werden kann.

Meaning (English)

umbauen means to rebuild / remodel / convert something—usually a building or room—by changing its structure or layout. It implies altering an existing thing rather than building from scratch.

Common translations:

to remodel (e.g., a kitchen, apartment)
to renovate / refurbish (when structural changes are involved)
to convert / adapt (e.g., turning a barn into a house)
to rebuild (especially after damage or major changes)

Parts (word formation)

um-: a prefix meaning around, over, re-, change—often indicating transformation or doing something differently.
bauen: to build.

So um-bauen literally suggests building in a changed way / rebuilding.

Multiple meanings / uses

Construction/architecture:
ein Haus umbauen = to remodel/rebuild a house (change rooms, walls, layout, etc.)
Conversion for a new purpose (technical/general):
ein Auto umbauen = to modify/convert a car (e.g., change it to run on gas, install special equipment)

German synonyms

renovieren (to renovate; often more about improving/repairing than changing structure)
modernisieren (to modernize)
umgestalten (to redesign/reshape; can be more general, also non-structural)
(etwas) ausbauen (to extend/expand; can overlap when remodeling includes expansion)
(etwas) sanieren (to refurbish thoroughly, often with repairs and modernization)