Do structural engineers actually over-design buildings

[@180MPH_In_The_Wrong_Lane]

I have atm my both feet in those two shoes. Yes the Civil Engineer and also the builder. At one end I'm designing my structures to be able to withstand all the possible loads and factors but also on the other end to build them according to local authorities guideline and standards without having to dig the pocket deep.

[@BrendanHasty]

Hi, that is an interesting spot to be in, it must give you alot of insight into both worlds.

[@dykodesigns]

Very recognizable. I work as structural engineering draftsmen / Bim Modeller, but I sometimes do basic structural calculations under supervison of a more experienced collegue. Over the years I have observed some interresting differences between builders and architects. Builders often like to penny-pinch and cut cost where ever possible, architects sometimes wear rose tinted glasses when looking at certain structural aspects of the design. Also I have experienced situations where the design gets a mayor overhaul because the builder wants a certain speed of execution in the project planning (because time = money), and those changes are then done shortly before construction starts. And Oh, and they expect the changes to be made yesterday and at not extra cost of engineering fees.

[@BrendanHasty]

Lol so true, sometimes they don't see the extent of work involved.

[@leviheath4533]

So true, glad to see a fellow draftsperson 🖐

[@leviheath4533]

Communication and management can certainly be a big hurdle

[@BoZhaoengineering]

The topic you are talking about is very interesting. Thank you for talking about the topic. Speaking of Euro Code, it apply a full statistic approach so called Load and Resistance Factor Design, LRFT for short. It has been said that American design code, Allowable Stress Method , ASM, is another choice alongside LRFT. In Euro Code, dead load is complied with Gaussian distribution. Live load is complied with Gumble distribution (or extreme value distribution). The wind load is Rayleigh distribution statically described. But it is still complicated that probability density function has multiple random variables, which represents the ‘unknown’ factors in reality. Further algorithm is still needed to proceed in statistics in order to get the load factor(s) or safety of factor. Speaking of the materials, the situation is even getting more complicated due to the materials used is assumed to go through a series of (random) events or it is called load combinations. As a result, materials used in design are undertaking assumed load combination. These two statistics phenomena are combined together and convolution integral is used to convey the random process as well as calculating the safety of factor we may use in design. DNV issued a safety of factor, 1.0 , in fatigue analysis exclusive to a Chinese wind turbine blade brand which is just specific to the verified product model, glass fiber made wind blades for the brand. Load situation is complex, building or/and equipment is getting smart and our clients get cost sensitive. Factor design seems more important than ever. I appreciate you bring so much insights and information on this interesting topic.

[@BrendanHasty]

Thanks for your detailed response, and the support. I enjoyed this topic too, hope to deliver more insightful content.

[@malikdaniyel146]

Hi Brendan, your skit reminded me of a similar situation I was involved in a few years ago where the contractor and architect was second guessing my design. You highlighted many key factors in this blog. The variation and performance of material, usage of buildings/ structures etc. Sometimes you will design a structure to accommodate specify loads and may nit be aware of the structure undertaking an excessive amount of loading that was not analyze. Therefore it's important to adopt initiative ideas when uncertainty develops. Thanks for the video. Malik

[@BrendanHasty]

Hi Malik, it seem common practice to second guess the engineering design. But they typically want you to make the change but not take any responsibility. Thanks for watching.

[@malikdaniyel146]

@@BrendanHasty That's correct and just to save a few dollars (profit over performance).

[@DeepakKrishna11]

Very interesting topic, and as always a common scenario in the construction field. Keep it up. And I know that you have touched this topic in this video a little bit but, can you please do a video on load combinations since I have seen engineers use combos which are not directly mentioned in the codes?

[@BrendanHasty]

Hi Deepak, thanks for the support. I was thinking or making a video on the difference between the codes around the world, this would cover load combinations.

[@DeepakKrishna11]

@@BrendanHasty thanks

[@bluelinemaths5153]

I learnt so much from watching this! Highly recommend

[@BrendanHasty]

Hi Blueline, glad that you enjoyed it. Thanks for the support.

[@PaulGrosvenor1]

Great video. Love that quote!

[@BrendanHasty]

Hi Paul thanks for the support glad that your enjoyed it.

[@bunbun-pu5rf]

So nice explaination.Thanks.

[@BrendanHasty]

Thanks for the continued support. Bunbun.

[@leviheath4533]

your a legend m8, really appreciate your videos, very informative

[@BrendanHasty]

Hi Levi glad that you enjoyed it thanks for the support.

[@JoePRush]

I explain it simply. There is over design and under design. You pick

[@BrendanHasty]

Hi Joe, guess you are correct if you design to code it is over design, as you need to cover so many situations.

[@enjek5654]

I understood it. It’s bang on.

[@billj5645]

Consider the collapse of Champlain Towers condominium in Florida. Study of the drawings indicates that there are some areas that were underdesigned. The structure stood for 40 years then failed. So it is difficult to justify that something worked in the past so it should be completely acceptable. As far as the public is concerned, either it works or it doesn't work. You would need a time machine to go far into the future to determine the answer to this. Engineers are tasked with protecting the safety of the public, not the maximum profits of the contractor.

[@BrendanHasty]

Agree that our job is to make the building save. but you are paid by contractor, not the public not that this is an excuse. So easer said then done, engineers need to deal with many conflicting goals. If you over design you never get another job, so the real goal is save but efficient. Some times with many examples such as the westgate bridge failure no one knewn about a structural behaviour unless detailed research after the failure.

[@mohamedashfaque1911]

Hi I'm a structural engineer from India, I'm well versed in designing aids such as Etabs safe sap2000. How's the scope for structural engineers in Europe. I'm good at performing dynamic analysis of high rise structures such as modal analysis, bucking, creep, and also have experience in Structures with torsional irregularities. I would really love to work in Europe countries. But I'm not sure how i can get there.

[@BrendanHasty]

Hi Mohamed look at getting your IstructE

[@yekutielbenheshel354]

You missed a crucial point that is often overlooked... having a canary in the coal mine. When buildings are built, when feasible, they should have myriad little indicators that enable a keen observer to ascertain points which are beginning to fail. Particularly because cheap microcontrollers have enabled a boom in cheap, yet remarkably powerful IoT (Internet of things) devices (for example, think of the awesome power of a 10 US dollar Arduino device), it's more feasible than ever to monitor the "health of a building" like a doctor checking the vital signs of a patient of his.

[@BrendanHasty]

Health monitoring is a great idea. This is something I did for my thesis. It would also give engineers better confidence in their designs.

[@yekutielbenheshel354]

@@BrendanHasty It's a huge opportunity to decrease the cost of building, maintaining, and insuring structures. I'm surprised insurance companies haven't aggressively pushed health monitoring. I can imagine entire departments within insurance companies that actively monitor structures they insure. I imagine that they would regularly require their insureds to make structural improvements to "sick" buildings. Overengineering structures and then waiting for them to "die" is inane these days.

[@nemesisgaming8360]

Hey Brendan, I've been following your channel since Steve told me about it, he is one of my best mates :D Tell him Scott says hi! I'd love to hear his reaction when I chat with him next (we talk pretty much every day as we're gamer buddies :P)

[@BrendanHasty]

Hi Scott, thanks for the support. I will let him know, I am sure he will be happy.

[@havensmith6374]

Love the video!

[@BrendanHasty]

Thanks for the support Haven Smith.

[@the3rdmaster311]

It really depends on the architect

[@BrendanHasty]

It always depend on the scheme, but as engineers we need to help guide the design in the right direction.

[@RyanSmith-re6ov]

Great video

[@BrendanHasty]

Thanks for the support Ryan.

[@ISCDesignArchitect]

YES in many cases engineers DO 'over-design' structural elements; and that translates to extra costs. As an Architect- managing engineers and the structural design is a key important skill that must be done at design stage-NOT when builder is starting on site!!:) However we trust the engineer's professional training, knowledge and thats what they do; its just as the professional architect-our job is to negotiate design solutions with the engineer.

[@BrendanHasty]

Hi Ibrahim, agree a good scheme is where you make most of the savings. And This should be in design phases, it is too late when the builder is involved. It is also important for engineers to understand the architectural process to lead to the best design for the project.

[@ISCDesignArchitect]

@@BrendanHasty yes. were a great team together; structural engineer & architect! No architect can operate without a good structural engineer. Me personally-I work hard with my engineers but I always try to lead the design stage so the engineers can achieve the design solution I wish; sometimes they think Im mad! 10 m cantilever? cmon man.....:)

[@Ooze27]

@@ISCDesignArchitect i'm struggling to think of a situation where a 10 meter cantilever will be cost efective compared with other situations. They must work in tandem and not force one to accept a solution, just because. Besides, most architects have a very basic knowledge of structural systems.

[@ISCDesignArchitect]

@@Ooze27 yeah i do agree. we hold a basic knowledge only in structure. Even myself with 25 +years of experience on countless small & large buildings and many with very inventive structural design concepts-. thats because while engineers were 'actually listening in maths class and studying'- architects were messing around and were not too smart. :)

[@Ooze27]

@@ISCDesignArchitect I'm not saying that. You were the one diminishing other people's work by saying they over-design. You find over-design in engineers with little experience, Regulations and codes exist for a reason. I have no doubt that a 20+ year experience architect has a good understanding of structural elements. Just like i have no doubt that a structural engineer with 20+ years of experience, knows a lot more than said architect (in structural systems, that is). Just like i believe i couldn't do an architect's job, i don't like that an architect tries to push structrual design down my throat when i know exactly what i'm doing. It's not called engineering for fun. As for the last point, most architects i worked with from several different countries were intelligent people, but their knowledge of structural systems was basic for some of the arguments they tried to push, which is natural since they didn't study it.

[@mrp973]

Loved the intro! Nailed it! Me as engineer Iam soft enough though to let the contractor do what they want most of the time. I struggle with this even now.

[@BrendanHasty]

Hi Mr P glad you enjoyed it. It is a hard skill to develop but worth it.

[@civilideas1925]

👍🏻

[@BrendanHasty]

Hi civil your support is greatly appreciated.

[@johnstrawb3521]

Oh, god. Just get on with it. Should have begun with 1:04.

[@BrendanHasty]

Hi John each yo there own some people enjoy it others don't.

[@itohsad]

It’s not as straight forward as it may seem. The human factor plays a role in how the structural design is made and how it’s calculated. For example: if you want a architectural design for your new house and meet with different architects you will get different designs. That’s just a fact. This is also the case with a structural engineer. He will design it, at least I hope so, in such way where he is comfortable with the structure. If that means he had a u.c of 0,80 and not 1,0 than that is his limits. His limit wil change with the experiences he gets.

[@BrendanHasty]

Hi Dashoti, agree that you will get different design with different enginers. However you should not be afraid to go close to code limits. There is a lot safety factors, however, there are some critical elements where you made add some redundancy. Sometimes you may not see the most efficient solution based on your past experience.

[@asiagreen5658]

The B1M KZbin CHANNEL (WHY NEW YORK BIllionaire row are half empty) - it's has amost 10 million view.

[@BrendanHasty]

I will need to check it out, thanks for the support Asian Green.

[@NixViche]

yes but actually no

[@BrendanHasty]

Hi Alec, some engineers do however even then designing to minimum standards people still think you are over designing.

[@NixViche]

@@BrendanHasty I agree, at the firm I work we often overdesign because of unknown live loads we anticipate especially on flooring, or on roofing if we think there can be roof equipment

[@GregNow]

0:19 ahahahhahaha 7:03 hahahhaha

[@BrendanHasty]

Glad that you enjoyed it

[@stephanc7192]

😂🤣😂🤣😂🤣

[@BrendanHasty]

Hi Stephen, thankas for the support.

[@fjsa_2471]

There are other reasons as well. 1) Covering their arses by extreme over-engineering. 2) Lack of skill combined with total ignorance of added project costs. I used to deal with structural engineers quite a lot and saw this happening all the time, especially on smaller projects. I'll give you 2 the most outrageous examples that I personally discussed with engineers and made them change the plans accordingly. Example 1: a simple steel frame with 90x35 timber planks attached (virtually no load on planks). 6 M16 bolts were specified as a way of connecting each of these 4m long planks to the frame. (WTF, seriously???) Example 2: a steel arch spanning about 10m. The plan specified RHS 150x150x9 for the arch. From experience on similar projects I knew that 150x150x6 would be sufficient. After having a conversation with the engineer he reluctantly admitted that 150x150x6 can also be used, and the reason he specified thicker section was that he 'felt that it will be better'. Yeah, right. Considering there were 7 or 8 of those arches we are talking about thousands of dollars of difference in fabrication/installation costs. Simply because somebody 'felt' something??

[@BrendanHasty]

Hey FJSA, I did bring up the some engineers over design thing, and I agree engineers shouldn't be scared of designing to code limits. Some critical element or a connection or two adding some redundancy but not to the point to blow out the cost. Thous examples sound crazy, and the engineers should look at the waste their designs produced.

[@chrisi1857]

Hi FJSA, those examples you’ve given don’t seem to be that bad, I’m surprised they stick in your mind to this day. I’ve seen stuff specified on drawings from younger engineers that would make all of us embarrassed for our profession. For example; Suspended PT slab with additional N16-200 T&B EW throughout. Or Specified to splice an N32 bar using site weld 8cfw x 1500 long Each side. That’s 3m of weld when 500mm would achieve the same result. Just got to realise that generally if someone doesn’t understand something they will err on the side of caution and go heavy. This can only be fixed with experience. But for those with experience, I’m all for putting that little bit extra amount of steel in the right places just to help us all sleep at night 😉

[@hadrienanglard4297]

That's why more experienced engineers need to help younger at the beginning of their carreer to avoid that kind of situations. I would also add that poor project management and huge work overload in a tight schedule can definitly lead to overdesign.

[@the3rdmaster311]

@@hadrienanglard4297 that's why architects have to take projects in charge, an engineer will never understand the impact dimension of a structural element on both the envelope and the function of a building, yes structural safety matters but not to the detriment of the other elements such as mechanical and electrical , don't forget that most people dies from fires due to electrical and mechanicaldeficiencies than structural ones

[@hadrienanglard4297]

@@the3rdmaster311 You are off-Topic and I don't know why you are telling me this. Structural engineers, like almost everyone else on this planet, are smart enough to understand the impact of their design if there is a good coordination and communication with the other project disciplines.