For a 'best practice guide' the Illuminating Engineering Society of North America (IESNA), the authority on best practices in the lighting industry, has formulated guidelines on positioning your recessed lights in the most effective manner. These steps cover the placement of recessed lights equipped with compact fluorescent bulbs. These bulbs are the best choice for high-efficiency lighting, since they use up to 75 per cent less energy, last six to 10 times longer and run cooler than conventional bulbs.
Locate recessed downlights directly above the front edge of the kitchen counter to light your workspace and the inside of your cabinets. Add additional downlights as needed to light the rest of the room.
Use wall washers to make your living room, bedroom, dining room or office appear larger. Space the lights the same distance apart from the wall and from each other. Space 13-watt lights a maximum of 3 feet apart, 18-watt lights 4 feet apart and 26-watt lights 5 feet apart. Do not aim the lights at windows or doors.
Use recessed downlights with clear reflectors for direct lighting in the living room, bedroom, dining room or office. Place 13-watt lights a maximum of 6 1/2 feet apart, 18-watt lights 7 1/2 feet apart and 26-watt lights 9 feet apart. The lights should be half those distances away from the wall.
Position 13-watt lights designed for wet locations over the shower and toilet, and centre a 26-watt light over the remaining part of the bathroom.
Centre recessed downlights along hallways using the same maximum spacing between fixtures as in Step 3. If you want to use wall washers instead, place 13-watt lights every 5 feet on centre and 18-watt bulbs every 7 feet.
Use higher-wattage fixtures if you have ceilings higher than 10 feet.