What are the merits and demerits of the Design and Built projects? 2

[defg]

It has been customirized that all engineering projects has to be designed by the appointed Consultant and the nominated Contractor by the Consultant/Client has to construct or build.That is to say the Design is carriedout by the Consultant.Built has to be carried out by the Contractor.But now days the role of design and built have been given to the Contractor.This implimentation has any foundamental experience or is that matter of sacrifing the strength and durability of the project?

 

[rowingengineer]

This is all about perspective, and the type of D&C you’re talking about. Taking the genral look at D&C shed/tilt box market:
If you’re:
The developer, you love the idea, you get a cheaper building that you can flog off. Not a fan of the developer quick build and sell type projects myself. There is always a time and expenses problem which leads to less durable products/quality products ending up in the buildings. However there are also build and own developers these guys are normally completely the opposite and are awesome to work with, but they normally don’t run technically complete D&C items.

The builder, you love the idea, you get to control the engineer, but you also better not stuff up, as there is no extra’s to be sort. But you also can cut money from the budget by getting less quality stuff.

The engineer, not as great as you loose the ability to enforce quality over cost. Generally the builder will have a set design, so they will use this, even when better alternatives could be sort. If there are problems on site with construction were you may ask for something but instead of having the backing of the client you will have nothing but your ethics. Can be hard when you’re trying to put food on your table.

The architect, Generally the building gets simplified and made a bit boring, your job in the need for money saving ends up just showing doors in the right place, no features ect.

The owner, Depends on your wants, but most building have higher maintenance costs for structural issues. The idea of the “old way” was the engineer was n your side and would make dam sure that you didn’t get a lemon, with D&C, there is a higher chance you will get a lemon.

The council, if a council project, you love this because you have no responsibility. Unfortunately this normally means councils have a high maintenance cost for projects, even simple ones. Which guess who pays for? Yes you got it, the tax payer.

I should also mention that the D&C area in my part of the world is heavily used in the sheds and tilt box constructions. This can even go to the point where an engineer will design a standard shed series that will be used for 1000’s of sheds that the engineer charges a pittance and the design end up looking like if was drawn on the back of a napkin. The need for savings in building has lead to a general lowering of the engineering design standard. This has also lead to engineers having to charge less to win the projects, which again has lead to lowering of design standards. Currently this is a major blight in my profession in my part of the world, with steps, being taken to rectify the currently design differences.

So it could be said that D&C projects has lead to a greater risk in design being taken by engineers. With effects like what I saw during Tropical Cyclone Larry in Innisfail the general conclusion from the reports thus far have been 90% of non expected structural failures were in the D&C shed market.


When in doubt, just take the next small step.

 

[hokie66]

A big, big subject. Design and Construct is a method of project delivery that has become popular over the last 20 years or so. It gives the contractor much of the control over projects that was traditionally assumed by the lead consultant, in the case of buildings by the architect. In my opinion, the contractors have been able to take control largely because of failure of the architectural profession to control costs and schedules. There has been mixed success. Quality does not have to suffer in the design-build environment, but sometimes does.

 

[Ron]

Good points by RowingEngineer and hokie66. Both on target.

When a non-engineer has authority over an engineer, and little understanding of the engineering process, then either the engineer has to compromise his design more than he would otherwise do and quality/reliability may suffer, or the project will make less money and the contractor/developer have to compromise profitability...which one will win?...I've seen very few developers sacrifice profit for quality, though I have dealt with contractors who would do so.

 

[BigH]

There is also the continuing negrayion of design to save money - do you really need a factor of safety of 3 on the piling design? Is 2.5 ok? Good, but now, we can gain if we can cut it down to 2 . . . how about 1.8 . . . - for some that are put in the position - it puts you between the rock and a hard place . . . How HR has ruined engineering firms these days . . .

 

[bimr]

The big merit of design/build is that design/build shortens the total project time.

The demerits of design/build include:
1. Poor project scope definition at beginning of projects. Project scope is typically defined 2-3 months into the project after preliminary work has already started
2. Tradeoffs on quality during the project to meet the project budget.
3. This type of project requires a more skilled project management staff.

 

[concretemasonry]

There was just a recent court case regarding the design and construction of a bridge between Minnesota and the "Republic" of Wisconsin. Minnesota had the responsibility for the project. It was a design build highway bridge over the St. Croix river, which is a very scenic and popular recreation area and the bridge also carries a lot of commuter traffic even though the old two lane lift bridge is a barrier to traffic. A decent bridge will attract more more traffic, so the scheduling and handling of traffic during construction is also critical. The site selection was established by both states.

The award of the contract to a design/build consortium that was not the low bidder, but it was selected and Wisconsin and some contractors filed a suit and that appeal was rejected.

The group with the the same group that rebuilt the 8 lane I35 bridge over the Mississippi River in Minneapolis. On that project, they were not the low bidder by $30-40 million and got a $20 million bonus for early completion (based on the formula of 1/2 of the excess cost caused in detours and traffic delays in the bid documents). The project was completed in 9 months (about 3 months early) and the $20 million more than covered the extra overtime and labor costs for the 24x7 construction. Strangely, there was barely a murmmer about the bonus since it wan fast and and cleanly according to the state requirements. The presentation blew all the price contractors out of the water and the PR and contact with the public before, during and after the construction was great. There even was an opportunity to for advance input on the noise/scheduling. The doors to the precast operation were open to all engineering groups and the media and the public had an opportunity to select the column/superstructure profile and even the color.

The key was the complete coordination of the design and construction for maximum performance. This permitted the fast completion under controlled conditions. The first concrete was poured when it was about -20F.

This is not the first done by the group in Minnesota. A few years ago, the same group did a much higher and possibly longer 4 lane replacement bridge over the Mississippi river in St. Paul that also required good appearance and on time or early completion.

As far as I know, they do not bother with buildings.

 

[JedClampett]

Our company has done limited design build. I was very skeptical at first about the same issues brought up above. It wasn't a bad experience at all. We weren't asked to compromise quality in any significant way. Permitting was very confusing (excavation was begun, reinforcing was ordered before any permits were obtained). However, the project was very profitable as contractors are not afraid to pay. Don't forget, they're used to paying subcontractors.
It was interesting to get their viewpoint (schedule was the most important factor, rather than materials) and what they're really concerned about (access; laydown; etc).
It all depends on the contractor you're teaming with.

 

[jgailla]

The construction is almost complete on my first design-build project as a design civil engineer.
This project has gone much more smoothly than many of my previous projects which have been run by architects.
I have not encountered any adversarial posturing by the contractor.
Part of this is also that the architects I have worked with generally do not know how to run a project. They are artists, which are necessary, but I cannot fathom how many clients do not seem to see their incompetence in project management and continue to pay out ridiculous change orders over the course of several projects.
There have been a few issues that have come up where I was pressured to back down. On a couple, I thought about it and decided that I might be too conservative and changed the specifications.
On things that I thought were more important, I wouldn't budge. The contractor complained a little bit but that was it.
We have a good relationship with the contractor even when they don't agree. They understand that the engineer has the final word and if they don't like it they'll get another engineer.
They continue to use us and I look forward to working with them again.
A couple of the engineers in my office are also doing design-build projects. In general, these projects run more smoothly than design-bid-build. I believe this is because everyone is on the same team rather than the contractor trying to squeeze anything they can out of the project.
I agree with JedClampett, it's all about the contractor. I wouldn't do design-build with a few of them.

 

[DWHA]

The first design build that the company I work for has ever done was just completed. I was the lead design engineer on the project and I think it went very well. I feel the key is to have a very good relationship with the contractor prior to doing a design build with them. The company I work for has been working with this same contractor for years before I began with them. Our company has a lot of trust in this contractor, and they have a lot of trust in us. They know we will not take short cuts, and they don't ask us to. Both the engineer and the contractor have to have a lot of respect for each other.

 

[rowingengineer]

I have just had the most unsavory experinace with a contactor/client. In this case, I didn't have much to do with the D&C only the construction inspections.

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When in doubt, just take the next small step.

 

[francesca]

In 20 years I think that all projects will have the contractor and designer appointed before the plans are finalized. Building Information Modeling (BIM)/Virtual Design and Construction (VDC) is going to revolutionize the industry. We will pick ourselves up out of the 20th century and join other industries and reap the productivity benefits of technology in Integrated Project Delivery (IPD). These buzz words are flying in informed architectural circles and around "mega" projects because the integrated process is infinitely more efficient and results in a better product.

http://architecturalgraphicstandards.wordpress.com/2008/05/09/bim-cmm-bicmm-says-sohail-razvi/