Who prepares early-stage (order-of-magnitude / preliminary / conceptual) estimates? Select the party most commonly responsible for feasibility-level and budget-level estimates in building projects.

Introduction / Context:
Early-stage estimates guide feasibility and funding decisions when design information is limited. These are order-of-magnitude and conceptual budgets that rely on parametric data, historical cost indices, and schematic take-offs. Assigning responsibility clarifies who should supply the assumptions behind the numbers.

Given Data / Assumptions:

• Project is at concept/feasibility or schematic stage.
• Limited drawings; heavy reliance on benchmarks and unit rates.
• Multiple parties can contribute, but one typically leads.

Concept / Approach:
In typical building projects, the architect/engineer (A/E) prepares preliminary and conceptual estimates tied to the evolving design, often validated by a quantity surveyor or cost consultant. A construction manager may also produce estimates in CM-at-risk or early contractor involvement models, but in traditional delivery, the A/E leads at this stage in coordination with the owner.

Step-by-Step Solution:
Identify which role has design custody and access to scope assumptions at concept level: the A/E.Acknowledge that CMs contribute when engaged early, but question expects the conventional answer.Select “Architect/engineer”.

Verification / Alternative check:
Standard practice guides indicate the A/E or a cost consultant under the A/E team prepares Class 4–5 estimates (conceptual), with owner approvals following.

Why Other Options Are Wrong:
Construction manager: feasible under certain delivery methods, but not universally the default.
Owner alone: lacks the technical detail and benchmarks without A/E support.
None of these: incorrect because A/E is a recognized preparer.

Common Pitfalls:

• Assuming the bidder's detailed estimate (post-design) is the same as conceptual estimates.
• Ignoring the role of independent cost consultants engaged by the A/E.

Final Answer:
Architect/engineer