Commercial buildings are usually designed to be space-efficient, creating the maximum square footage for a given dollar of construction cost. There's an undeniable logic to that approach, but the resulting buildings tend to be large boxes with the windows all along the outer edge. That means most of the people working inside won't have a window or natural sunlight, which is unfortunate but something you can work around.
Bring in Real Sunlight
Windows are prized in any office setting because natural daylight is the best lighting for office productivity. If you own your own building or have a lease that allows you to make improvements, you can find ways to route natural light even into an office with no windows.
One option is to use conventional skylights, but they're not always a practical choice in the real world. They won't work in multi-story spaces, for example, and aren't suitable for use with all types of roof. In a commercial space, sun tunnels are often the better option. These capture sunlight at the roof level and route it through reflective tubes to their destination, so they can run light to where it's needed just as your HVAC system routes heated or cooled air. They're suitable for any roof type and work with any interior ceiling as well.
Upgrade Your Fluorescent Tubes
If there's no natural light in your office, and installing skylights or sun tunnels isn't an option, you'll need to fall back on artificial lighting. The existing lighting in most commercial spaces is standard-issue fluorescent tubes, which are reasonably cost-effective but are generally loathed by the people who work under them. Most tubes don't mimic natural light very well, and some people are sensitive to their characteristic high-speed flicker.
The easiest upgrade is to change your fluorescent tubes to a color "temperature" that mimics daylight. It's measured in degrees Kelvin, and daylight-spectrum lights are usually somewhere in between 4600 K and 6500 K. You'll likely find the light to be much brighter and a bit bluer than you're accustomed to, but once you've had a few days to adjust to the difference you should feel a difference in your mood and energy levels.
Changing the tubes won't do anything to address that irritating fluorescent flicker, though, so if you have the budget you may be able to justify updating your fixtures entirely.
Other Windowless Office Solutions
One option is to swap out your conventional tube fixtures for their modern LED equivalents. Those are comparable in lifespan to regular fluorescents, though a bit shorter than extended-life tubes, and they'll use less power. They're also a more sustainable option because fluorescent tubes contain toxic mercury that needs to be safely disposed of at end-of-life.
LED lights are also available in dimmable versions, a luxury you don't get with fluorescent tubes. That's noteworthy because bright, glaring overhead lighting can be unpleasant for the people working under it, even when it comes in the otherwise-desirable daylight portion of the spectrum. Being able to turn down the lights as needed is a solid win.
Incorporate Task Lighting
Ultimately the best light is the one that's right where a user wants and needs it to be, so you may want to explore shifting your focus in workspace areas from overhead lighting to task lighting. Individual lamps and task lights have a number of advantages over fixed overhead lights. You can configure them with separate types of bulb – daylight for productivity, for instance, but something warmer for interviews or sales meetings – and place them where they're needed.
Task lighting also gives you the versatility to rearrange anything from an individual workspace to your entire floor plan, while still providing excellent lighting throughout. That's difficult to achieve with fixed overhead lighting.
Adjusting Your Office Ergonomics
You can double down on the effectiveness of your lighting upgrades by treating light management as part of your overall office design. High-gloss reflective surfaces are stylish and visually impressive, for example, but if you're using bright lights, the overall effect can be glaring. It's best to reserve those gleaming glass, metal and stone finishes for public settings – reception areas, showrooms and suchlike – and not your main working areas.
For actual office and production areas, switching to matte finishes is a good starting point. These absorb light, rather than reflecting it, so they'll soften the impact of bright bulbs. Lighting designers can draw on a number of other tricks and techniques, from sloped ceilings to translucent room dividers or strategically positioned plants, to similarly break up the flow of light through a workspace.
The end result is a more natural setting, with muted ambient lighting that makes it easier for individual workers to avoid glare on their computer screens and desktop work areas.