What is the difference between BIM and CAD?

As we all know, CAD is the abbreviation of computer aided design. I intend to use it to represent the time when people on earth basically got rid of the drawing board and never saw hand-drawn drawings again, that is to say, it has been almost ten or twenty years. The abbreviation of building information modeling is BIM, and I want to use it to express an era that we are entering and about to enter. Because that era has not really arrived, I don't know how to describe it more accurately. If I have to ask about the basic characteristics of that era, I can sum it up in one sentence, perhaps it can be said that the master is the most knowledgeable person. Of course, the era before CAD was manual, and its typical characteristics were sketchpad and T-square, so-called sketchpad. The reason for making such a statement is simple. No matter how the times change, the fundamental and goal of what we want to do remains the same: to build a better house in a more economical way and make human life more poetic. In the CAD era, some work still needs to be done in the manual era, such as counting engineering quantities; Some tools used in the manual age are still needed, such as design manuals. Similarly, when we enter the BIM era, some things we did in the CAD era still need to be done, such as structural calculation; Some tools used in CAD era are still needed now, such as rendering software and virtual reality software. So, what's the difference between CAD era and BIM era? 1. Tool level: CAD, such as Word, BIM, such as Excel, are analyzed from the main tool levels used in the two eras respectively. This analogy may be a relatively easy-to-understand method. If readers know that Word and Excel are more than CAD and BIM, it is estimated that this is not bad for most professionals in the industry. The same financial statement looks the same in Word and Excel, but it moves differently, just like a real person and his wax figure. If you push a real person, the real person will take a few steps forward. If you push the wax figure, it will only fall down. If we change a number in Word, other related numbers will not be changed automatically, and we need to make corresponding changes manually one by one. In Excel, it is different, because the data behind the report are related by different formulas except the surface of the report we see. Therefore, if a certain data is moved in Excel, all related data will automatically change according to the preset formula. In other words, a report that looks the same in Word is just a specific state of an Excel form, just like someone's positive image. But a person can take many kinds of pictures, except the side, back, top and bottom. Don't forget CT, B-ultrasound, X-ray and so on, provided there are real people. The difference between CAD and BIM is similar to the above situation to some extent. People usually express buildings through different views, such as plan, elevation and section. In CAD era, designers draw different views respectively; In BIM era, the same model gets different views. If we look at the plan or elevation of the two respectively, they are the same; However, when we change the type of a door and a wall, CAD may need to modify the drawings such as cross section and vertical section one by one, while BIM only needs to modify the corresponding components in the model. At the same time, in the process of design and construction, designers have to do structural calculation, thermal calculation, energy saving calculation, engineering statistics and so on. In the CAD era, every single adjustment needs to modify different calculation models one by one to reflect the influence of this single adjustment on other building indicators. When we enter the BIM era, the model expressing the building can be directly used for the above calculation, and each single adjustment only needs to modify the unique model to achieve high automation. Celebrities have said that the first person who compares beauty to flowers is a genius, the second is a mediocrity and the third is a fool. Let me explain in detail: comparing CAD and BIM to Word and Excel, I am definitely the nth one, and N>& gt3. 2. Methodology: CAD is the clothes I made for you, and BIM is the clothes I made according to your figure. Project construction is an activity involving many majors, and the number of majors can range from a dozen to twenty or thirty. Especially in the last hundred years, due to the wide application of electric power, air conditioning, communication, data, security, intelligence and other technologies in the construction field, the complexity of construction projects has increased geometrically. The above passage is a bit gentle, which is a bit inconsistent with the style of other parts. That's because I haven't figured out how to make it clear in vernacular. To put it simply, to build today's house, even if Mr. Luban is still alive, he can only handle two majors at best: architecture and structure. To build the present house, he also needs water luban, heating and ventilating luban, electric luban, energy-saving luban, communication luban, effect map luban and so on. Of course, we have all these rubans now, and even if necessary, there will be more rubans. The question is, how can so many Luban build a house together? Sure enough, he is an expert. You hit the nail on the head! I'm not going to talk about the history of building houses here, let alone the old accounts of the handicraft era. Let's see how the Luban people in the CAD era got the house out. The story of the CAD era: first, the building Luban appeared, and various horizontal and vertical profiles were drawn, and then handed over to other Luban doors. At this time, Lu Ban, the renderings, came. According to the drawings given by Lu Ban, he made a "renderings model" in a rough way, and then made architectural renderings, animations, virtual reality and other visual effects according to this model for the owners or judges to make decisions. Structural Luban needs to do structural calculation. According to the drawings given by architectural Luban, a "structural calculation model" is made in a rough way, and then an extremely complicated structural calculation that other Luban doors can't understand is carried out, reinforced and a structural diagram is drawn. Then Lubanmen came with all kinds of machines and pipes. On the drawing, he saw the boards being erected, punched holes in each wall, and then created several "electromechanical calculation models". On these mechanical and electrical models, the calculation, analysis and simulation of various mechanical and electrical majors were carried out, and mechanical and electrical drawing was started. It's time for Luban to go out. According to these drawings, a "calculation model" is established to calculate the volume of concrete, the length of pipeline and the number of equipment. Finally, work out the cost of the house. The fashionable green Luban came, looked at these drawings, established a "green building calculation model", and began to calculate the green buildings that save materials, water, land and energy for the benefit of the future, and even calculated the carbon dioxide emissions. After the house was built, the property owner Luban came, so he quickly established the "property management model" and established the great cause of building operation and maintenance on this basis. Why are you so wordy? Report readers, this is a super simplified version. We haven't considered what will happen when Luban finds out that the place where he wants to take the pipe is occupied by other Luban. Chairman Mao said, "Dead people often happen." It's not that serious here, but Luban's family blocked Luban all the way. See the doorway? Shall we summarize it here? First: Lubanmen is very hard. Before he practices his own works, he must make a "XXX model" by himself. Owners, are these "XXX models" the same as the houses you want? You believe that Lubanmen can do anything, right? To say the least, even if it is done right the first time, can all Luban keep pace when they encounter "design changes" or "mistakes and omissions"? Second: Of course, it takes time to repair the "XXX model", although for the owners, time is money. Third: Can these "XXX models" concocted by Lubanmen be used in future operation, maintenance, reconstruction and expansion? If building a house is compared to cutting clothes, every Luban in the CAD era makes clothes according to his own specialties, but you think that every piece of clothes is not suitable for you in some way and can't be put on. Of course, Lu Ban is a good Lu Ban. The problem is that every Luban must make a model of you that he understands before making clothes for you, and then cut clothes according to this model. Let's see what's different in the coming BIM era. The story of BIM era: What if the owner invited a BIM Luban to help the owner build, manage and update a model that is exactly the same as the actual building and can be used by other Luban? Building Luban should draw a horizontal profile, and the owner ordered BIM Luban to find out the materials needed for the horizontal profile from the BIM model of building Luban; Structural Luban needs to do structural calculation, and the owner ordered BIM Luban to find out the information needed for structural calculation from BIM model to structural Luban. If adjustment is needed after calculation, BIM Luban will update the adjusted information into the BIM model; The electromechanical Luban is like this, the green Luban is like this, and the cost of Luban is like this ... BIM Luban can find and solve the struggle between different Luban because it helps the owner put all the information of Luban in the same BIM model. At the beginning of bidding, BIM Luban can not only help the owner to prepare a drawing that solves all kinds of mistakes and omissions, but also hand over the designed BIM model to the construction Luban, asking the construction Luban to show the bidding scheme on the BIM model. Moreover, the actual progress of the construction site during the construction process can be compared with the planned progress on the BIM model. By using the BIM model to solve the problems in the construction, new information can be updated to the BIM model simultaneously. After the house is built, this changed and updated BIM model is the same as the actual building. It can be used for marketing, sales, operation, reconstruction and expansion in the future. If you still use clothes as a metaphor, it is called tailoring: your body, your clothes. Last question: BIM Luban = BIM consultant. 3. Achievement level: CAD makes designers work faster, and BIM is what owners know best. Q: Who benefited the most from the handicraft era to the CAD era? A: Designer. Q: What is the biggest benefit for designers? A: Drawing is much faster. Q: Who benefited the most from the CAD era to the BIM era? A: The owner. Q: What will be the biggest benefit for the owners? A: Save money. Less changes, less rework and less extra investment. Q: What else? A: Save time. Any problem can be solved at once. Q: What else? The quality of the house has improved. There is no need to build and smash, and there is no need to dig a hole. Q: What else? A:No. Q: Is it really gone? A: The master became the master. The master knows everything. The owner became the person who knew his house best, and the owner became the person who knew himself best.