What should specifications provide to help accurately estimate costs in construction?

Specifications should provide material quantities and usage to help accurately estimate costs in construction because they give a detailed breakdown of what materials are needed for the project, including the type and amount. By outlining specific requirements for each component, specifications ensure that estimators can calculate the exact quantities of materials necessary for construction, which directly influences overall project costs.

Having precise material quantities allows for better budget planning and reduces the risk of overestimating or underestimating costs. This level of detail helps contractors procure the right amounts of materials without waste and ensures that they meet the design and performance criteria laid out in the specifications.

Other aspects like historical data, labor costs, and general estimates are indeed useful in the costing process but do not provide the specific, actionable information necessary for accurately estimating the quantities of each material needed. Therefore, focusing on material quantities and usage is crucial for developing a realistic and detailed cost estimate for construction projects.