They are refurbishing the old house and plan to move in next month.

refurbishing 是动词 refurbish 的现在分词形式。refurbish 由前缀 re-（表示"重新"）和 furbish（"擦亮、整修"）组成，意思是"翻新、整修"，指对旧物品或建筑进行全面清洁、修理和更新。