Wow, that is a challenge. With all those skylights I don't imagine it would require any artificial lighting in the daytime. How do you intend to use the space at night?

Hi,
Uplighting works really well in an atrium, as the light always is coming indirectly from above. On a few projects we've used track-light type cans mounted to collar ties that happened to be needed as structural members. This allowed the fixtures to be placed all across the space, but in your case, light valances could be utilized, running the atrium's perimeter. You can also use fluorescents.
Casey

I can't understand the design without a section but if there is no one on a higher level that can look down into the lighting I always use powerful halogen up lights surface mounted on walls. They are thin and only project 6 to 8 inches.

Thanks everyone! Our contractor also suggested uplighting the atrium when we mentioned we wanted to add lighting. Whatever we choose to do, we need it to be high efficacy or dimmable (preferred) as we need to comply with CA's title 24 lighting rules.

Ok, so now that we all agree that uplighting is the way to go, let's talk practical details. How should we go about this? Track lighting on the top of the horizontal beams? Wall sconces? Some sort of ledge going around the perimeter that will hide the lights? In general, how far from the ceiling should these lights be? If we do up lighting, should we also plan a couple of strategically placed pendents?

Jon is right, during the day there's plenty of light; it's just at night that we need illuminate it. Previously it housed a bunch of plants, but with the new ceiling and flooring, we're going to use it as a sitting or dining room (TBD), so night time lighting is a must.

I can't tell how big those beams are, but I wonder if you could mount low-profile, high-CRI T5 fluorescents (or compact fluorescents) on top of them. They'd wash the ceiling, which should give excellent, diffuse indirect lighting throughout the room. If you use 2700K or 3000K color temperature, they will blend well with any incandescent accent lights you use.

You need to tell us more about the space. Meeting energy limitations for lighting such a large space is so difficult that I would strongly suggest using a professional designer. It might save you from doing it twice.

Davidr, looking at the plans, the beams are 4x8's and it appears that they'll be mounted with the narrower side on top. Will that be enough room for what you've suggested?

Title 24 does not dictate how much lighting one can use, but what type. For a living space, the lighting has to be either a) high efficacy; b) have manual on occupancy sensor; or c) have a dimmer.

Mightyanvil, let me know what additional info would be helpful, and I'll do my best to supply it. Would it help if I took pictures of the current space? Construction of the new roof hasn't started yet, but I could take pictures of it with it's old roof.

You might consider a line of articulated pl lamp fixtures that would run across the top of the beams inside the atrium. This would allow the lights themselves to remain hidden by the beams yet provide indirect lighting from the ceiling. I have placed a link to Primus Lighting that may have photos and diagrams of products you might consider. They are a manufacturer and sell through distributors only, but will be happy to refer you to the proper distributor in your area

Here is a link that might be useful: Primus Lighting