While the factory is nearing completion, other aspects such as a new wind tunnel remain a little further down the line.
It is those pieces Fallows suggests separate Aston Martin from the teams at the front of the F1 grid.
“We've definitely got facilities to be competitive, but we have to be realistic that we are not at the same level as the top teams,” he said.
“And I say that from the point of view of the facilities rather than the expertise. I think we're very strong in that regard.
“I was very, very impressed with the just general level of expertise that we had in the team when I joined.”
Fallows came to Aston Martin having been Adrian Newey's understudy at Red Bull, taking on the role of Technical Director.
He was a high-profile signing amid a swathe of new hirings during a period of expansion.
Fernando Alonso has also joined the team this year, in place of Sebastian Vettel who retired at the end of 2022.
Alonso comes from Alpine, which finished fourth in last year's constructors' championship versus seventh for Aston Martin.
However, the two-time world champion sees potential in the squad, as does Fallows.
“The key bits that are missing are the wind tunnel, which we're clearly looking at,” he said.
“We are very fortunate in using the Mercedes wind tunnel at the moment but there are limitations to that.
“There's no substitute to having your own; the flexibility of testing the way you want.
“There are simulation facilities and so on that are also going to come online,” Fallows added.
“Does that stop us progressing in the way that we want? Absolutely not.
“But are they key for us as a sustained performance gain in the future? Absolutely, and that's why we need to push for.”