Estimating help

[chrislsnider]

After 13 years of doing this, I'm being asked more and more to provide cost estimates on projects, but have no background in doing so. For designed projects I can easily calculate volumes of concrete, tonnage of steel, and then call producers for prices. What do I do for new construction estimating for things that haven't been designed yet? I know of RS Means and things like that - are they good enough to generally get me in the ball park? Should I look for a 1-2 day course? If so, any suggestions?

 

[DaveAtkins]

I use R.S. Means for almost all of my estimating. I have found you get a reasonably conservative estimate most of the time.

DaveAtkins

 

[allgoodnamestaken]

Get your company to pay for the training and call it professional development. What do you have to lose?

 

[Guastavino]

Chris,

Beware of the liability that you are taking on by doing these estimates. Make sure you disclaimer them sufficiently. Get with your insurance carrier, they should be able to help you. The last thing you want is to underestimate and they try to get you to pay the difference because of your underestimate.

As for R.S. means, I think it's the industry standard where I'm at. With that said, there are a lot of nuance things to include. I haven't done a formal estimate with it, but in looking at it, I see lots of factors, etc. that are probably easy to include, but I wouldn't know when/when not to. In other words, just be careful if you use RS means to make sure you read through everything thoroughly.

 

[chrislsnider]

AllGoodNames - that is the intent. I'm just fishing for names of classes.

njlutzwe - that's my main concern in doing any estimating.

Even if it is a 'class' in how to use RS Means, it would be helpful...

 

[IRstuff]

Do you have billing records from previous jobs? This is actually the most critical part, yet most companies seem to be clueless about this.

Using historical records, you scale the scope of most reasonable projects accordingly. To wit, if a new project is 3 times the size of a previous job, you can scale the historical data, and throw in a safety factor to cover the unk-unks. It's harder to attack historical billings than to attack "engineering estimates."

You should stay away from oversimplifying your hour estimates, i.e., you should have subtasks that are on the order of 1 to 2 manweeks of effort. This makes it harder for the customer to attack the numbers and negotiate a lower bid. The rationale is that while the percentage pad might be the same, it's harder to argue that an 80-hour task should only be 72 hr, while it's easier to argue that an 800-hr task can take an 80-hr "challenge."

TTFN
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[Guastavino]

IRstuff, I think he's asking about construction costs, not his design costs.

 

[IRstuff]

It sounded to me that getting any cost wasn't an issue, rather it was the scoping of the task, particularly if the design doesn't exist.

The bottom line is that for a new project with no a priori design, then the OP needs get someone to do sufficiently accurate proposal design that can be used for estimating purposes. That's not necessarily something a cost estimator can do on their own. Once that's done RS Means could be used to estimate costs, but if you have your own historical costs, so much the better, since there are always nuances that cannot be reflected in a generic estimate.

TTFN
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[MrHershey]

What njlutzwe said. Make sure it's very clear in everything you're giving them that the estimate is just that, an estimate. It's not a guarantee of quantity or cost and I would also include a recommendation that the contractor or owner perform their own takeoffs and estimates if they haven't done so already. We do this for contractors and owners kind of as a selling point for our services. We just provide quantities though, not cost. Concrete numbers are easy to pull out of Revit and we can base pounds per square footage of rebar and PT on other projects as well as analysis model runs if we've gotten that far along. But the main point is that it's *another* set of numbers, not *the* set of numbers. Idea is to give order of magnitude (1000 cubic yards of concrete vs 10000 cubic yards of concrete) to give them a second opinion to their own. It's not to pin down what their bid or budget should be for them. Usually we'll do this for schematic and design drawing phases to help them with their planning, I don't think we've ever done it on construction-level drawings.

Just have to make sure there's nothing that they could construe as you saying 'this is the cost', and giving them an opportunity to come after you when the cost is inevitably different. It's very likely that your (or your company's) professional liability doesn't cover this and will leave you high and dry if anyone is ever able to successfully claim you guaranteed or even implied a guarantee of a cost.

 

[BAretired]

I found cost estimating to be the most difficult and least accurate part of an engineering assignment. Some clients didn't require a cost estimate and that was good. That was why I preferred working for contractors who did their own cost estimates.

Government clients usually require a cost estimate of the work when the drawings and specifications are complete. This is brutal, particularly when the economy is hot because it means that bidders are simply not hungry. Today, I read in the local paper about a hospital in Alberta where the prices came in at three times the cost estimate. I don't think it is possible for a consulting engineer to take all of the economic factors into account when making a cost estimate, so perhaps it is not a reasonable expectation to demand cost estimates of architects and engineers.

I always breathed a sigh of relief when bids came in close to the estimate but it certainly was not always the case; I have never heard of a client holding the engineer or architect financially responsible for the cost estimate, but there have been cases where re-design was demanded in order to bring the project in on budget; and some clients are not keen on paying additional design fees for that type of re-design.

BA

 

[chrislsnider]

Thanks for all the thoughts guys. It's good to hear that I'm not alone here.

Volumes and tonnages are easy - especially in Revit, it's the labor that is the hard part. I just ended up sticking my wet finger in the air to see which way the wind was blowing and decided that it should take "X" laborers "Y" hours to finish the work at "$Z/hour". Giving the client that SWAG was sufficient in this instance.

 

[WARose]

If you are estimating something that hasn't even been designed yet, you'll have to go by approximations. For example, for a process building, my guesstimate is typically around 20-25 lbs/sf for steel. You can run rough numbers for the foundation based on that guess (and known wind and seismic criteria). But probably the best advice I have is (especially in alliance type work with a client) is document your assumptions. (Including keeping a copy of the scope as it stands when you do your estimate.) People have a funny habit of changing things and then wondering why structural changes to accommodate them.

As far as prices go, you'll need to do the leg work as far as contacting contractors. That's where being buddies with the local steel fabricator/foundation contractor pays off.

What gets me is: I've worked at a number of places that actually had "estimators". Yet I was the one who had to get prices for these guys half the time. I asked my boss once what was the point of having them around if they don't do anything other than dumping my quantities in a spread sheet? So I feel your pain.

 

[MrHershey]

BARetired - Have heard that too, about engineer or (usually) architect having to re-design and then getting stiffed on the bill because in their contract they had agreed to design to a budget. That's one of those instances where you really have to be careful with the contract language. And it might not even be something you specifically agreed to in your contract, some clients will include clauses in your contract with them that you have to meet the requirements in their contract with the owner. So the 'design to a budget' clause may be in their contract and you'd still get held to it and be doing a bunch of free work.

 

[Brad805]

Do you have any contractor's that you trust? If so, sub it to them and review it. Engineer estimates are notoriously low because we do not swing the hammers. If it is all new, past projects can work fine, but if a renovation this will never work. Quantity surveyors are only a tad better in my view. On one reno project we had a QS involved. They paid this firm something like $50k for all of the estimates. The first time I thought it was fine to be using unit values based on areas, but as the design team finalized the design I thought they should start estimating man hours, equipment, materials, site constraints, local material costs, cranes.... They never did. I told the Arch that the $6mil budget was low. They said, oh no, they have done this many times. Low bid was $10mil. Not a good use of $50k in my view. The re-design time always annoys me in those cases.