The extension and structural alteration of an existing building; the construction work to expand or remodel a building.
古い家を増改築して二世帯住宅にした。
We extended and remodeled the old house to make it a two-family home.
増改築には建築確認申請や近隣への説明が必要になる場合が多い。
Extensions and alterations often require building permits and explanations to neighbors.
予算の都合で、増改築の規模を縮小することにした。
Due to the budget, we decided to scale down the extension and renovation.