Constructability
Constructability
(OP)
Partially out of curiousity, I would like to hear from those in purely design environments how much consideration is given to constructability.
Roughly %50 of my time is spent doing construction engineering (which probably means >%80 of my projects). As we do construction engineering and frequently have contractors as clients in design build projects, constructability is stressed as very important.
Many of the designs that cross my desk as a construction engineering project would get me a stern talking to from the boss if I tried to send them out to a client as a design, due to construction issues.
I see minor issues like easily avoided underhand field welds all of the time. It can be done, but it's a pain. The larger issues aren't quite as frequent, but things like pre-stressed girders which need post-tensioning on the top flange just to get them to site, circular concrete columns that are not a standard tube size and girders that cannot be erected singly still show up too often. Most issues like this that I come across can be checked early in design in under ten minutes, something that gets drilled into me every time I don't check something.
So, how much consideration do you give to such things?
Roughly %50 of my time is spent doing construction engineering (which probably means >%80 of my projects). As we do construction engineering and frequently have contractors as clients in design build projects, constructability is stressed as very important.
Many of the designs that cross my desk as a construction engineering project would get me a stern talking to from the boss if I tried to send them out to a client as a design, due to construction issues.
I see minor issues like easily avoided underhand field welds all of the time. It can be done, but it's a pain. The larger issues aren't quite as frequent, but things like pre-stressed girders which need post-tensioning on the top flange just to get them to site, circular concrete columns that are not a standard tube size and girders that cannot be erected singly still show up too often. Most issues like this that I come across can be checked early in design in under ten minutes, something that gets drilled into me every time I don't check something.
So, how much consideration do you give to such things?






RE: Constructability
You are getting great experience, whether you choose to stay in construction or at some stage work in a design office. I believe constructability is at least as important as many of the other things that designers do routinely. It has always been a primary consideration for me, but unfortunately for all.
RE: Constructability
It's a two way street. When's the last time any of you got a complement from a contractor or owner that this design was easy to build? I realize that it's our job to consider this, but a little positive feedback would work wonders. Because we certainly hear the negative.
RE: Constructability
For example, we designed several flat slab jobs and tried to make the drop panel depth a dimension that would be a wood 2x4 or 2x6 dimension to hopefully make it easier to build. One of our contractors told us that was better. A job or two later, the contractor wanted to know why the heck we did that!
Another one had to do with consolidation of steel beam sizes. We tried to group them as best we could, but were told later by one contractor that this approach was stupid, that they went straight by the weight and nothing else.
On one job, we caught a little flak in a meeting with the owner, architect, and GC, for over-consolidating (his opinion) the base plate sizes. I have no doubt that if we would've used 40 different base plate and anchor rod combinations, they would've screwed up some of the anchor rod placements and gave us crap over that.
RE: Constructability
You can also read a lot of things put out by AISC that try to get you to minimize connection costs by upsizing members but I don't know if it always gets an appropriate price reduction when it is bid, and more often I am afraid they look at weight. These kinds of things have come back on me a few times with someone thinking we had overdesigned the project. In fact, I would really like to know how other engineers feel about upsizing to save cost in such instances. I am sure it varies by region and the market of the contractor.
For all other cases where I control smaller field installation type things, I always choose the most constructable way. It is good to do this so when you go to the job site some guy is not asking 'WTF were you thinking'?
RE: Constructability
i have seen things on drawings that were impossible to construct, but then again, we picked up the phone and discussed it with the designer to decide on the appropriate fix. today's contractors start screaming about change orders and delays. i feel that we (engineers interested in a productive project with a good quality product at the end) are often too easily convinced to accept something other than what we are normally comfortable with. i have taken the attitude that if the client or contractor feels they want a cheaper product with another firm, then that's where they should go. "cheap is cheap" is the motto we use. we might miss out on those revenues but then again we don't get sued over stupid crap for the sake of keeping someone with unrealistic expectations happy.
likewise, now that i'm with a testing firm, if the structural engineer will put out a letter saying they are satisfied with subpar test results, then that's their call...it definitely will not be my call.
please keep this in mind: for everything you see screwed up, there's 10 things just like it somewhere else. now just imagine if no one is watching at all........in other words, put your own considerations first and foremost because no one is looking out for you. to hell with anyone asking "WTF are you thing?". tell them to sign off on the design if they don't like it...that's my opinion for what it's worth.
RE: Constructability
As they say, "make something idiot proof and someone will build a better idiot."
RE: Constructability
RE: Constructability
I wrote an extensive rant on this and then deleted it. Good Luck!
RE: Constructability
as long as the designer and architects are making a real effort to not overcomplicate the design and thoroughly think through what's on the paper, that's all anyone can ask. if there's many real problems with the drawings, then the contractor should keep the guy that drew the things on the phone all day every day until the thing is built. i actually had a large job with 1000+ rfi's and almost 2000 sketches by the time the job was done. the architect finally put one of his guys on the job 3 days a week to work through the issues we had. there were several issues but many were somewhat unforeseeable or were a result of things having to be changed which started the snowball effect. sometimes, the job is complicated and just has to be worked through. we worked with everyone and the architect and engineer worked with us and we got the thing built on time with several months to spare and under budget (under budget from the contractor's standpoint--think the owner spent more than they were supposed to since they kept expanding the design). most contractors i see today could not have built that job like that. we were good and made 2.5mil in profits after all the bills were paid and had a good job (i wish i could've seen some of those profits to make up for all the long weeks and headaches).
RE: Constructability
RE: Constructability
It is only on unusual buildings with construction stability issues that I would examine it in depth.
csd
RE: Constructability
I chalk up the ratio of thanks for a good design to complaints for any design as human nature. I expect to get more complaints than thanks for anything I do. That said, I have received a number of compliments in the past months.
Hokie
I agree that I am getting great experience doing what I do. From the designs I see every day there are many things that some designers do not account for. For someone without years of experience it also means many more challenging and interesting problems.
I'm adding things to my lists of things to try to avoid or never do in a design on an almost daily basis. I beleive the latest is never design a composite beam that cannot support the weight of the slab before they are composite.
271828
I had a very simiar situation, where keyways where designed to allow use of one ripped 2x4. The precaster complained and we switched to a form requiring 3 or 4 seperate members in its place. Some people will always be stuck in thier ways. I would much rather deal with that than deal with trying to convince an old hand that the way they've always done things is no good anymore due to code changes.
I'm not too surprised to see most saying they consider constructability, those not doing so would be less likely to respond, and even further are probably less likely to spend time pursuing thier trade in off hours and hence not post on these forums.
From what I see consideration varies wildly from firm to firm. I almost dread getting a construction project when the design was done by certain firms. I know it will mean fights with both the contractor and designer to try to come up with something that works.