However, pre-restoration surveys of a site may differ dramatically from what is actually revealed when the structure is dismantled, and a proposed restoration may undergo numerous redesigns and be subject to continually increasing costs. In addition, public funds inevitably carry with them many restrictions in terms of time and budget.
然而，古蹟未解體之前的調查，往往與拆開之後差距極大，面臨一再變更設計或追加預算時，公務機關在預算、時間上難免多所限制。