Estimating quantities for building projects involves calculating various elements such as earthwork, foundation concrete, and brickwork. Different methods are employed for this purpose, including the Long Wall – Short Wall Method, the Centreline Method, and the Partly Centre Line and Short Wall Method.
This method involves categorizing walls into long and short walls. The long wall is considered to be along the length of the room, while the short wall runs perpendicular to it. To determine the length of these walls, the centerline lengths of individual walls are calculated first.
For the long wall, the length is determined by adding half of the breadth at each end to its centerline length. Conversely, for the short wall, half of the breadth is subtracted from its centerline length at each end. The length of the long wall generally decreases from earthwork to brickwork in the superstructure, while the short wall length increases. Multiplying these lengths by the breadth and depth yields the quantities needed.
This method is particularly useful for walls with similar cross-sections. The total centerline length is multiplied by the breadth and depth of the respective item to obtain the total quantity at once. When cross walls, partitions, or verandah walls intersect with the main wall, the centerline length is reduced by half of the breadth for each junction. Careful consideration of these junctions ensures accurate estimation. Estimates derived from this method are known for their accuracy and efficiency.
This method is employed when the external wall (surrounding the building) has a uniform thickness, while internal walls have different thicknesses. In such cases, the centerline method is applied to external walls, while the long wall – short wall method is used for internal walls. This approach accommodates variations in wall thickness and foundation levels, making it a preferred choice for engineering departments.
By employing these methods, accurate estimates can be generated for various building works, ensuring efficient planning and execution of construction projects. Each method offers distinct advantages depending on the specific requirements of the project.