What if any liability would an engineer have in the following situation? This is specifically in reference to engineering within the USA.

An engineer produces a design and plans that meet the standards and codes in effect at that time. The design is sealed and submitted to the owner for bidding and construction. Because of funding constraints, the project is put on hold. Enough years pass that there have been code changes that would affect the design. The owner then bids and completes the project as originally designed. This assumes that no engineer was later retained to look at the plans and update them.

  • What is the engineer's liability for any issues that arise from using the original codes? This assumes that the later codes fix errors or make other needed improvements.
  • Would it matter if the engineer was aware that the project was being constructed to the original plans after the delay? The engineer is no longer under contract.
  • $\begingroup$ This would seem to be a question of law, rather than of engineering principles. It needs a legal expert to answer it, not an engineer. And given the absence of information about which legal system applies here, and what the contract stated, I suspect that this would be unanswerable even for a legal expert. $\endgroup$
    – 410 gone
    Feb 12, 2015 at 11:00
  • $\begingroup$ Related meta question: meta.engineering.stackexchange.com/questions/205/… $\endgroup$
    – user16
    Feb 14, 2015 at 14:46

4 Answers 4


This is a question about the law, not engineering, and the law is entirely dependent on the jurisdiction. Assuming that we are dealing with a common-law country like Australia, the UK or the US then liability can arise from three sources: the contract, statutory liability and the tort of negligence.


Basically, you owe an obligation under a contract to do what it says in the contract; noting that this may contain implicit terms and terms read into the contract by statute.

Liability under the contract arises to one party when the other party breaches a term or condition of the contract. If you have complied with the contract then the delay cannot have caused you to stop complying.


There may be laws in the relevant jurisdiction (which could be the jurisdiction of the owner, the engineer, the site or all of these) which impose a liability on the engineer. If this is an obligation to be read into a contract then see above. If this is a duty owed to the State, then it would generally be for the state to prosecute either criminally or civilly.

In most jurisdictions, compliance with a code or standard is at best a partial defence, so if you have not complied with the law initially then you would be liable. Most laws are not retrospective so it is difficult to see how the delay could change your liability.

However, in circumstances where you know that the project is being constructed to obsolete codes and these may cause a breach of the new statute (particularly one going to WHS or environmental damage) there is probably an obligation to do what you can in the circumstances. Drawing this to the owners attention would probably suffice for this.


In order to establish negligence as a Cause of Action under the law of torts, a plaintiff must prove that the defendant:

  1. had a duty to the plaintiff,
  2. breached that duty by failing to conform to the required standard of conduct (generally the standard of a reasonable person),
  3. the negligent conduct was the cause of the harm to the plaintiff, and
  4. the plaintiff was, in fact, harmed or damaged.

A case bought where the engineer was in ignorance of the project proceeding would fail on the first limb. If the engineer was aware the owner would still find this a difficult hurdle - what duty does the engineer owe to the ex-client? If they could overcome this they would probably fall foul of 2 and 3 - the engineer could quite reasonably assume that the owner had engaged others to update the plans. Note that I have not even considered that there must be actual harm or damage.

Notwithstanding, if the engineer, on becoming aware, wrote to the owner to say "Hey, I hope you are not using my plans because they are out of date" then I would suggest that this would be all that a "reasonable person" could do.

  • $\begingroup$ Might I add, if your concern is legal proof of the acknowledgement, keep a copy of the letter you send to them. A date-marked hard copy, if possible. $\endgroup$
    – Zibbobz
    Feb 12, 2015 at 18:11

First, I think it's important to note that actual legal liability is going to vary case-by-case, it's never so simple as "They were the engineer, it's their fault." In situations where something happens and lawsuits are drawn up, they're probably going to name every single company who is at all related, and all key people in those companies responsible for the design. However, I think I can give some general insight based on my experiences and what I've been told in legal liability training.

Personally, I lay the majority of the blame in this situation on the owner, who uses plans that are years old without having anyone qualified look at them and update them. I've seen (small) issues with this in my position. Drawings are completed and sent to another department for approval, and for whatever reason, they sit on an application engineer's desk for months, sometimes close to or upwards of a year. The drawings are then sent out as-is, but internal changes that have been made to drawing standards since the drawings were originally updated aren't complied with. These are minor issues, but it's easy to see this occurring on a larger time scale and with more serious consequences.

The drawings should be dated. That's fairly common practice, and this is one good reason why. We want to know when the drawings were made, to determine what things have changed since that design, whether that be standards, codes, laws, or simply interfacing parts. If the drawings are made to the codes and standards in place at that time, I don't see how the engineer can be held responsible for that design, unless it can be shown that the engineer had knowledge of the code needing a revision for safety issues. In this case, making the print fit the code isn't good enough, because we know the code won't prevent some issues.

It really comes down to the fact that, in the design process, every consideration towards safety needs to be taken, and where risk cannot be eliminated, it needs to be made clear what the risk is and how it can be mitigated by the end-user.

On the second point, this sounds like a very gray area, and I really couldn't discuss any legal aspects of this. But I will say that I think, if an engineer knows that the design being built is out-of-date and could cause issues in some manner, they have an ethical responsibility to contact someone still affiliated with the project and apprise them of the situation. It may not be their legal responsibility, but I think it's clearly the right thing to do.

It should almost go without saying that any engineer still affiliated with the project has the same obligation, only stronger, to say that the designs need to be updated and they cannot be used in their current form.

To give some context for this, the main product that my company manufactures can be extremely dangerous in its operating environment. Guarding is absolutely required unless the product is entirely shielded by other parts of the machine. The guarding itself may vary slightly from company to company, but its largely the same because it's governed by an ISO standard. However, this standard has changed over the years, and even the organization that creates the primary standard has changed. This means that we have old designs which feature old guarding that are still active in our system. We have one employee who is extremely knowledgeable about the industry and in particular the safety codes and even sits on some safety committees. He makes sure that new designs comply with the guarding standards and that old products are updated as necessary. Sometimes this means going so far as to tell the customer that we won't sell them this product if they won't let us update the guarding (newer guarding is in some cases more expensive). He isn't always the most popular person, but this is his job, and that's how we manage our code compliance in a world where codes and standards are not consistent.


Where I live at least, the governing codes active at the time that a building is permitted apply to the project, regardless of when construction starts. As you probably know, even if a new code is published, it doesn't have the force of law until referenced by the appropriate authority having jurisdiction (AHJ.) In practice, this means there are often 1-3 years where a new code is available, but not yet binding. Of course, if an engineer is aware that the code has become more strict or closed a loophole, but chooses to follow the provisions of an older code still in effect, they may be acting unethically and open themself up to liability issues.

The written analysis that the engineer prepares will reference the edition of the code that the analysis is based on. As long as they aren't intentionally taking advantage of a loophole, I think clearly stating the code version used should be sufficient.

I'm not sure how well this translates to industries where the code requirements are specified by customers rather than the government. I imagine there is a similar (if shorter) lag between the publishing of a new code and its common adoption. Another thing to consider is that many codes are published with fairly minor changes that wouldn't make a large difference in the acceptability of a design. When a code changes drastically, industry publications, vendors, and regulators tend to start active education campaigns to make people aware of the changes. For example, here in California, our Green Building Code just underwent a major revision. As a result lighting and control system vendors hosted a number of seminars to explain the impacts to specifiers and electricians (and advertise their products, of course.) This means that for a major code change, the industry becomes aware of the new requirements and would be more likely to catch any outdated designs.


The engineer's liability could either be to the owner or to the public (i.e. public safety).

The main possibility for liability to the owner comes from the contract. The engineer should make sure that the contract states what standards apply - either by including dates of specific standards or referring to a set of standards "as at the contract date" (or similar wording). If the standards are updated during the design period, if it is a safety critical aspect, then the owner would need the design to meet the latest standard; but as the engineer isn't contracted to that latest standard, there would need to be an extension/alteration to the contract = additional fees for the engineer.

In terms of safety liability to the public, it all comes down to what the engineer knows. e.g. If the new standard was released during design, the engineer should be aware and should inform the client, and negotiate new fees (or refuse to continue the design if the owner won't agree). If, as in your situation, it is many years after the design was completed, then it would come down to whether the engineer knows that the building is now being built, and whether he could know that the original design has not been updated for the latest standards. It would be a hard task for someone to prove that the engineer knew exactly what was going on and deliberately took no action (i.e. informing the owner or a public safety body).


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