Plinth Area Estimate
The plinth area estimate is a method of estimating the cost of construction based on the plinth area of a building. The plinth area is the total built-up area of a building at the floor level, including the thickness of the walls. It is calculated by multiplying the length and breadth of each floor and summing them up.

Detailed Estimate
A detailed estimate involves a thorough analysis of all the components of a construction project, including the quantities of materials, labor, and equipment required. It takes into account the specifications and drawings of the project to calculate the costs accurately.

Revised Estimate
A revised estimate is an updated version of an initial estimate, which takes into account any changes or modifications that have occurred during the course of a project. It is typically prepared when there are significant variations in the scope of work, quantities, or rates from the original estimate.

Supplementary Estimate
A supplementary estimate is prepared when there are additional works or changes in the project that were not included in the original estimate. It is used to account for any new requirements or variations in the scope of work.

Least Accurate Estimate
The plinth area estimate is considered to be the least accurate among the given options. This is because it relies solely on the calculation of the built-up area without considering the detailed quantities and specifications of the project. It does not take into account the variations in materials, labor rates, or any other factors that may affect the overall cost.

In contrast, the detailed estimate provides a more accurate assessment of the project cost by considering all the necessary components and quantities. It takes into account the specifications and drawings, allowing for a more detailed and precise calculation of the costs involved.

Similarly, the revised estimate takes into account any changes or modifications that have occurred during the project, ensuring that the cost estimate reflects the current scope of work.

The supplementary estimate is prepared to include any additional works or changes in the project, ensuring that all the costs are accounted for.

Therefore, the plinth area estimate, which relies solely on the calculation of the built-up area, is expected to be the least accurate among the given options.