A four-character set phrase parsing as
高 'tall' +
楼 'multi-story building' +
大 'big' +
厦 'mansion / large building' — two near-synonyms doubled for emphasis. The pattern of Adj-Noun-Adj-Noun is hugely productive:
高山大海 'high mountains and great seas',
千山万水 'a thousand mountains and ten thousand rivers'.