Construction projects rarely fail because of a single major issue. More often, they are affected by a series of small mistakes that gradually increase costs, delay completion, and create unnecessary disputes. Whether you're building a new home, extending an existing property, or managing a commercial development in London, avoiding these mistakes can save thousands of pounds. This is where a Quantity Surveyor (QS) becomes an invaluable part of the project team. A Quantity Surveyor is responsible for managing costs, controlling financial risks, preparing procurement documents, monitoring budgets, and ensuring that construction projects remain commercially successful from concept through to completion. Professional quantity surveying services can significantly reduce project costs through accurate cost planning, tender analysis, procurement advice, value engineering, monthly valuations, and final account management. Here are ten of the most common-and expensive-construction mistakes ...