Is there any difference in EVA construction time?

[Stretchytall]

I've noticed that, when I build new solar panels (or other external construction), all my EVA Airlocks participate in the construction. But it doesn't seem to make a difference in construction speed whether one of them is active during construction or all of them are active during construction. Is this correct?

It stands to reason that the construction should go faster if multiple EVA Airlocks are engaged in the construction. It seems cheap that I should be able to turn off all EVA Airlocks other than one, and the construction time is the same.

I would recommend to the Devs that construction go faster if multiple EVAs are assigned to construction (give the player a choice). Or that there is a penalty if the player turns off EVAs during construction.

[Amanoob105]

Near as I could ever tell, no. Multiple EVAs only help with hull repairs by default, which is their main use.
If you want things to build faster you'd need to research the option, which is likely related the mechanical reason it doesn't otherwise, though personally I find there's better things to spend the points on.

I can't think of a lot of, legit, reasons you would turn off an EVA once built. You typically build them as you need them to keep up with hull repairs, in turn as you open up new sectors.
The best reason I can think of is building them in advance of needing them, but keeping them turned off until then to save on power and/or because you lack the workers. Which is what happened in my last game.