Centre-line method in estimation — suitable building shapes For which plan geometries is the centre-line method especially convenient and efficient for quantity estimation?

Introduction / Context:
The centre-line method is a rapid technique for estimating quantities of walls, foundations, and superstructure where measurements are taken along the centre lines of walls. It is particularly effective when wall thickness is uniform or changes are systematic around the layout.

Given Data / Assumptions:

• Plan shapes involve symmetry or repeating segments.
• Wall thickness is either constant or changes in a predictable way.
• Openings are adjusted systematically.

Concept / Approach:
By summing the lengths of centre lines and multiplying by uniform widths or depths, one obtains quantities quickly. For curved or polygonal plans (circular, hexagonal, octagonal, other regular polygons), centre-line computations simplify repetitive corner allowances and reduce arithmetic.

Step-by-Step Solution:

Verification / Alternative check:
Contrast with long-wall/short-wall method on polygonal plans; centre-line method reduces corner corrections and speeds up takeoff.

Why Other Options Are Wrong:

• Each single geometry listed is indeed suited; therefore choosing only one is incomplete.

Common Pitfalls:
Forgetting to correct for wall junctions where double counting may occur; applying the method blindly when wall thickness varies irregularly.

Final Answer:
All the above