Hello, everyone.
This is Enta.
Are you doing cost estimates?
Well, when it comes to cost estimation, I think it’s mainly handled by general contractors and branch-level contractors.
If it were a company that only takes on subcontracting work, you might hardly ever see it.
The design documents include design drawings, design calculations, bill of quantities, and the design cost.
To put it simply,
Design Plan → Design Specifications + Design Drawings → Bill of Quantities → Estimated Design Cost → Bidding → Successful Bid (Design Cost) → Construction → Final Inspection
The cost estimate is based on the design cost for this section.
We determine the design budget based on the design drawings and the quantities specified in the design.
In other words, they are determining the amount of money needed for the construction work.
Then, after the general contractor wins the bid, we submit bids and perform the construction work as first-tier and second-tier subcontractors.
You often hear from general contractors, “We’ve got a construction bid coming up, so please give us a quote based on the design specifications,” right?
By finding out the subcontractor’s price before the bid is awarded, the general contractor can determine how much to bid (at a discount of XX%).
If it's a construction project we really want, we might bid at the very minimum acceptable price, or—in the worst-case scenario—we might even go ahead with it even if our bid is below the minimum.
And the general contractor has a pretty good grasp of the government agency’s estimated design budget. (This isn’t a scam.)
That’s because it’s derived from the design drawings and the design quantities. (These days, I consider cost estimation to be a technical skill as well.)
This is a rough overview of cost estimation, but if you’re not familiar with the theory and concepts behind it, you’ll end up calculating a completely different figure. So, I’d like to introduce a website here.
Here it is.
There has never been a site like this before.
Or rather, when it comes to cost estimation, public works projects are full of “black box” elements.
Approaches vary from one local government to another, and they differ completely between agriculture and forestry on one hand, and civil engineering on the other.
In some cases, this may vary by district.
Cost estimation is quite a complex field, so I only have a basic understanding of it.
I've become completely reliant on the software, so when I get stuck, I look it up in a book, but even then, it's still a bit of a struggle.
A must-see for anyone involved in cost estimation!
See you later.
