Best Cost Methods for the various phases of design
Can anyone concisely explain the best cost methods for the different phases of design.
Programming
Schematic Design
DD
CD
CA
Thanks again!
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Programming & Pre-Design:
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Area, Volume, or other Single-Unit Rate Methods
Based on cost per square foot or cubic foot, cost per unit, or historic data from similar projects of similar size
Schematic Design:
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Elemental (Assemblies & Sub-Systems)
Based on cost per functional categories like systems, partitions, foundations, finishes all together
Design Development & Construction Documentation
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Quantity Survey Method
Extremely detailed, calculating the exact number of each building element/component (e.g. number of bricks)
Construction Administration
No cost estimation required according to B101, bidding has already occured, the contractor's work determines the real project cost. -
Area, Volume, or other Single-Unit Rate Methods
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I can see that a cost estimate can be conducted during Programming, but do contracts require that architects estimate the cost in the Programming Phase? The answer is NO. It depends on the contract. The typical contract stated that cost estimation starts at Schematic Desing. Am I wrong? I remember having read about this, maybe for Project Management. Owners can estimate costs very early before involving an architect but Architects will be involved with the cost estimate at the end of the first phase, Schematic Design. Let me know if you have another point of view. Thanks
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AIA B101-2017 requires the cost estimate to be updated at every design phase of architectural services (See sections 3.2.6, 3.3.2-3, and 3.4.4-5). It does NOT, however, require that the cost estimate become more detailed as the project progresses. Each of those sections make reference to Section 6.3.
Section 6.3 states, "...The Architect's estimate of the Cost of the Work shall be based on current area, volume or similar conceptual estimating techniques. If the Owner requires a detailed estimate of the Cost of the Work, the Architect shall provide such an estimate, if identified as the Architect's responsibility in Section 4.1.1, as a Supplemental Service."
It should be noted on this thread that there is a difference between the architect's cost estimation responsibilities and the contractor's.
Kevin Griendling, AIA
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