Elmore Leonard once wrote an entire book around his 10 rules of writing. Every night, David Letterman has his Top Ten list. Even God had his 10 rules, although He called them Commandments. I guess you can get away with that when you are God. I spent the last month building a new darkroom, during which time some things became evident to me that seemed to neatly fit into a ten-list. Having used all those brain cells thinking about them, it made sense (at the time, anyway) to write them down and share them with the little part of the world to which I have access. I am not nearly as well known as God, Elmore Leonard, or David Letterman, so I could not bring myself to call them rules, and certainly not Commandments. As Captain Hector Barbossa said, theyre really more guidelines than actual rules. So here they are: The Home Depot Rule does not apply to darkroom construction. For the unenlightened, the Home Depot Rule says something to the effect that any home improvement project will cost twice as much, take three times longer, and require at least four more trips to the home improvement center than originally anticipated. Being a photographically-related project, I instead offer the Inverse Square Law of Darkroom Construction, to wit: the cost, time, and trips required to build a darkroom are inversely proportional to the square of the funds, time available to spend on the project, and the proximity to the closest home improvement center. It is impossible to have too many electrical outlets in a darkroom. Figure out how many you think you will need, then square that number. Then add another stop or so for good measure. Too much is never enough. There is no such thing as too much storage space. Guideline #2 may be equally applied to shelves and cabinets. Nature, it is said, abhors a vacuum, so your storage space will soon be filled up, but look at all the cool stuff you will have. If some is good, more is better. Buy or build the biggest sink you have room for. My first darkroom was designed to make 8x10 prints comfortably, because that is the largest print I had ever made up to that time. I cursed the lack of sink space every time I later printed 11x14s. My new darkroom is built to handle 16x20 prints with ease, and 20x24s in a pinch, even though I dont plan to print that large. Yeah, right. Use plastics instead of metals wherever you can in your darkroom. Darkrooms eat metals, which is a disturbing fact when you consider that silver is at the heart of the analog photography process. Mr. McGuire gave Benjamin Braddock good advice when he said, I have one word for you, son: plastics. Fermats principle states that "the actual path between two points taken by a beam of light is the one which is traversed in the least time." In other words, a straight line. Fermat, however, apparently never worked in a darkroom or he would have known that darkrooms are like black holes that attract any unsuspecting photons that happen to be speeding by. They bend, bounce, corkscrew, infiltrate, penetrate, and scoff at matte black surfaces, all so that they can fog the best negatives you have ever made as you load them into your daylight tank. There is no principle that states that darkrooms are like black holes that attract every unsuspecting dust mote that happens to be passing by, where it inevitably settles onto the negative currently in your enlarger. Dust can be defeated. Clean your darkroom once in awhile. Keep the door shut to keep out dust and things like cats that bring dust into the darkroom. On one of your innumerable trips to the home improvement store, buy a little HEPA air cleaner for your darkroom. The reward for a really clean darkroom is almost never having to spot prints. Provide visual cues for things as you implement your darkroom construction plan. Sketch little drawings of anything that is not plainly clear to you before committing building materials. Mark out the locations of equipment as construction progresses. Write H and C to avoid mixing up hot and cold water feeds (a sure way to waste an afternoons work.) Graph paper, masking tape, and a Sharpie were my most valuable tools when building my darkroom. Dont forget about HVAC. HVAC is not some long-discontinued paper with reputedly magical powers that produces highlights so luminous that they glow in the dark. No, HVAC stands for Heating, Ventilation, and Air Conditioning. Most darkroom chemicals work best at about 68 degrees farenheit. Happily, so do most people. The closer you can keep your space to this temperature, the less time you will spend heating or cooling your solutions before you can use them, and the more comfortable you will be. See #10. Make your darkroom as hospitable as you can afford. If it is a pleasant place to be, you are likely to spend more time there. If you spend more time there, you are likely to make more prints. If you make more prints your prints are likely to get better. If your prints get better you are more likely to become rich and famous. If you become rich and famous, a golddigger is more likely to get her (or his) claws into you, and as happened to O. Winston Link, lock you in your darkroom making prints that she (or he) sells for ill gotten gain. If this should happen to you, at least you will have a nice place in which to be imprisoned. See how it all works out?