noun
Refers to the act or process of reconstructing or rebuilding a building or structure. Often used in architectural, urban planning, or disaster recovery contexts.
地震の後、市は古い建物の再建築を進めた。
After the earthquake, the city proceeded with the reconstruction of old buildings.
この地域では再建築が制限されている。
Reconstruction is restricted in this area.
改築 means renovation or remodeling, implying changes to an existing structure, whereas 再建築 implies tearing down and building anew.
Compound of 再 (sai, 'again') and 建築 (kenchiku, 'construction, building'). The exact historical derivation is uncertain, but the word follows a common pattern of prefixing 再 to nouns to indicate repetition.