https://www.farmersjournal.ie/farm-producing-54-million-eggs-per-year-609746

This article highlights an Irish egg laying barn system that was being intentionally built prior to this flu. The image captioned "A view of part of a section of the multi-level free-range laying house" shows off a modern barn.

https://www.poultrynews.co.uk/production/egg-production/analysis-who-will-pay-for-the-new-barn-eggs-standards.html

Same thing here, although you can at least see there's some free space they're not making use of.

That's the intentional barns, too. I wonder if the producers who weren't intending for full-time barn raised chickens had decent facilities for them.