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Should We Believe the Claims of Architects and Engineers for 9/11 Truth?

Probably the best-known group which promotes the inside-job conspiracy theory about the September 11th attacks is Architects and Engineers for 9/11 Truth, also known at AE911Truth. Inside-job theorists are often known as ‘truthers’ (among other things).

What Should Non-Experts Do?

When confronted by a question which requires technical expertise you do not possess, the only rational course of action is to reflect the balance of expert opinion. Rational lay-people apply this principle to topics such as the relative safety or harm of vaccines, the flatness or roundness of the Earth, the approximate age of the universe, and whether or not humans have set foot on the Moon.

If a substantial number of relevant experts support a particular interpretation of an event such as the collapse of the World Trade Center towers, the non-expert is obliged to treat that interpretation seriously. If a particular interpretation is supported by only a small proportion of relevant experts, the non-expert is justified in dismissing that interpretation, at least provisionally, until further evidence or a better argument becomes available.

Architects and Engineers for 9/11 Truth

The AE911Truth group’s website claims that “3000+” qualified professionals have signed its petition claiming that the World Trade Center towers collapsed due to controlled demolition. Even though there must be more than that many qualified architects and engineers in the world, 3000 nevertheless sounds like a respectable number. If that many believe the theory, there must be something to it, one might think.

What Proportion of Experts Does AE911Truth Represent?

What proportion of architects and civil engineers is represented by the 3000 or so members or supporters of the AE911Truth group? A web search in January 2025 revealed the numbers of qualified (‘licensed’, ‘registered’ or ‘chartered’) architects and civil engineers in three English-speaking countries.

The Number of Architects in the US, UK and Australia

Here are the latest figures for architects:

The Number of Civil Engineers in the US, UK and Australia

Here are the latest figures for civil engineers (for sources, see https://www.structuralbasics.com/how-many-civil-engineers/):

  • USA: 307,570 in 2022
  • UK: 92,600 in 2022
  • Australia: 56,100 in 2019

(That site also gave the latest figures for the number of graduates in civil engineering in Germany: 228,000 in 2012.)

The Number of Architects and Civil Engineers in Canada

Here are some figures for Canada:

That figure for civil engineers seems anomalous: it’s similar to the USA’s figure despite the fact that Canada’s population is only about a tenth of the USA’s. To be safe, let’s ignore Canada.

The Total Number of Architects and Civil Engineers in the US, UK and Australia

Here are the totals for the USA, UK and Australia, rounded down (to be as generous as possible to the AE911Truth group) to the nearest 10,000:

  • Architects: 170,000
  • Civil Engineers: 450,000

The Proportion of Architects and Civil Engineers in the US, UK and Australia Who Support AE911Truth

It appears that there are well over 600,000 architects and civil engineers, just in three of the world’s many industrialised countries. The AE911Truth group’s “3000+” architects and civil engineers represents about one in 200, or half of one percent, of the total from the USA, UK and Australia.

The Proportion in the Rest of the World

What about the rest of the world? Let’s continue our generosity to the AE911Truth group, and assume that the proportion of architects and civil engineers in the rest of the world’s population is only one half of the proportion in the three industrialised countries already considered. Here are the latest approximate population figures:

  • USA: 340 million
  • UK: 69 million
  • Australia: 27 million
  • The rest of the world: a bit over 7.5 billion.

The combined population of the USA, UK and Australia is a little over 430 million. The number of architects and civil engineers in those countries is a little over 600,000. That is a proportion of one in just over 700 of the population, or roughly 0.14% of the population.

The population of the rest of the world is around 7.5 billion. If we assume that the proportion of architects and civil engineers in the rest of the world is a half of that in the three industrialised countries mentioned, it will be roughly one in 1400 or 0.07%. Seven point five billion divided by 1400 equals 5,350,000. That’s the approximate number of architects and civil engineers we might expect to exist in the rest of the world.

Add that figure to the roughly 620,000 architects and engineers in the USA, UK and Australia, and the total number of architects and engineers in the whole world may be, very roughly, six million. For every qualified architect or engineer who actively supports the inside-job theory, there may be around 2,000 others all over the world who do not, a proportion of 0.05%.

The Proportion in the USA Alone

Perhaps it isn’t fair to count every architect and engineer in the whole world, since the AE911Truth group’s members are likely to be predominantly English-speaking Americans. It might be more reasonable to compare the group’s membership only with the combined total of architects (121,368) and civil engineers (307,570) in the US: just under 430,000. For each one of the “3000+” architects and engineers who belong to AE911Truth, there are roughly 140 architects and engineers who don’t actively promote the inside-job theory, a proportion of 0.7%.

Even using the most generous set of figures, the 9/11 inside-job theory appears to be actively supported by well under one percent of those who possess the relevant technical expertise. It’s a very small minority indeed.

In reality, the proportion is likely to be even smaller than that, since those who possess the expertise to evaluate aspects of the evidence in this case would include other professionals such as metallurgists, chemists, and engineers other than civil engineers.

‘Engineers Assess the Truth in AE911Truth’

A 2021 article by David M. Scott and Ron Hamburger, ‘Engineers Assess the Truth in AE911Truth’, available as a PDF download from https://www.metabunk.org/threads/debunking-resource-engineers-assess-the-truth-in-ae911truth-scott-hamburger-2021.12016/, argues on pp.14-15 that the number of experts cited by the AE911truth website as signatories of its petition, “3000+”, is likely to be an exaggeration, and that the proportion of experts who support its claims is in fact tiny.

Scott and Hamburger provide figures for US holders of the title Professional Engineer, which is given to all types of engineer, not just civil engineers, and for members and fellows of the American Institute of Architects. They make several interesting claims:

  • Of the roughly 800,000 PEs in the USA, 98 had signed the petition.
  • Of the roughly 31,000 PEs in New York, six had signed the petition.
  • Of the roughly 95,000 members of the American Institute of Architects, 235 had signed the petition.
  • Of the 3,200 Fellows of the American Institute of Architects, seven had signed the petition.
  • Of those seven, three were no longer alive.
  • Of those who were no longer alive, one appears to have been added to the AE911Truth’s petition two years after his death.
  • AE911Truth’s petition does not contain physical signatures; it is “essentially a 20-year collection of unverified signatures.”
  • Some of the people cited as signatories of the petition claim that they only contacted the group to request information, did not sign a petition, and do not support the group’s views.
  • AE911Truth’s actual membership may be as little as a few hundred.
  • Some experts cited by conspiracy theorists (not necessarily the AE911Truth group itself) claim that their views and opinions have been misrepresented.
  • The more relevant the specialists, the more likely they are to dismiss the AE911Truth group’s claims. According to Scott and Hamburger: “There are no tall building experts and no prominent structural engineers who support the controlled demolition conspiracy theories.”

Should The Public Believe or Disbelieve AE911Truth’s Claims?

The conclusion is straightforward: the claim made by Architects and Engineers for 9/11 Truth — that scientific evidence demonstrates that 9/11 was an inside job — is supported by only a tiny minority of those who possess the technical expertise to evaluate that claim. The general public should reflect the balance of expert opinion and disbelieve the claim.

Incidentally, the founder of the AE911Truth group has expressed some other weird ideas: