Conceptual estimating is not just pricing a drawing. It is how an estimator converts a scattered set of information into a number they will stand behind — systems, code, quantities, and the things the drawing (if there even is one yet) left out. Cost is already the main design input estimators think in, it just shows up last on paper.

How do estimators actually price a concept design?

Estimators don’t have time to wait for a constructible model with complete fidelity. They work off of conceptual designs which means pulling what they can off a PDF, fill in any gaps, then apply judgment: unit prices, systems, contingencies.

The designer’s drawings are something estimators have to rebuild from, quantities get traced off it and then the two sides trade revisions until the numbers align with the Pro Forma constraints.

“We’re constantly getting what-if scenarios. [Our designer] will go back and update the plan. We come back a few days later and work out a new revision based on that tweak.”
— VP of preconstruction, National GC

Estimators live within a world of incomplete information. One example a precon leader talked us through is if the takeoff lands at 1,000 sf per caisson, he knows it is wrong — it should sit closer to 350–500. He invents the rest. That is why the estimate is a second model.

“We are actually doing all the hard work of grabbing and getting the data off the drawings or off the massing.”
— VP of preconstruction, National GC

What are estimators actually pricing at concept design?

Conceptual estimating mirrors conceptual design in cycling through as many iterations as possible taking into account a variety of factors. Preconstruction leads are focused on structure, skin, HVAC, the legal envelope and dozens of other factors.

“You oftentimes will get a client that says, I want windows everywhere. Well, okay. If you want windows everywhere, you have to up your HVAC system to a point where it meets regulations. And if you want to have floor-to-ceiling glass around the perimeter, we’re going to need to get creative as to how we deliver it to the exterior facade.”
— Preconstruction lead, California based GC

What does “confidence” mean when the design is still a napkin sketch?

Confidence is a cost you can stand behind, anchored by an estimate rooted in the construction scope of the proposed design options.

“The big problem is always the early stage of the project where without spending too much money and designing too much, you need to have much more confidence and clarity in the cost. From a design standpoint, we need to quickly verify different options… the facade, the structure, whatever options.”
— Preconstruction lead, Regional GC

Getting to a place of confidence for estimators is a matter of balancing science and art - all while juggling time constraints. The science is the taking off of areas, the mapping to historical projects, the application of construction systems their company has implemented on dozens of past projects. The art is the instinctual craft of the judgement calls that are made based on that science: the choice of $/ft2 within the historical costs, the time to commissioning, the contingency to carry in the estimate.

Do estimators want to design the building?

They want the design used as a communication tool so the estimate has boundaries.

“We are not trying to be an architect. We are not trying to take the creativity away… what I’m trying to create is more like [design] as a communication tool that everyone understands what costs are based on. So we all know what the boundaries are”
— Preconstruction lead, Regional GC

None of this is architects failing to think in numbers, or estimators failing to think like designers. Cost lives one file and one revision cycle behind the design that produced it — the second model, the tool switch, the ratio checks, the boundary drawn after the fact. Estimators already treat cost as a design input. The industry just built a process where cost shows up last.

FAQ

What is conceptual estimating?

Conceptual estimating is pricing a building before the design is constructible. Estimators rebuild the mass as systems, code, and quantities, then apply judgment to unit prices, systems, and unusual conditions. It is not a square-footage multiplier.

What information do estimators need from a concept design?

Enough geometry to take off structure, skin, HVAC, and the legal envelope — plus details that may not be captured in conceptual design.