The Design Ground Rules You Need to Know Before Breaking Them

Most of us have a firm sense of what we like and dislike when decorating a room—we've seen enough magazines, TV shows, Instagram feeds, and furniture stores to know our style (or at least what we definitely don't want in our room). But decorating takes more than just a sense of style to look right—proportions and design rules are equally important. We often hear interior designers talk about scale when referring to good décor. You can buy the most beautiful chandelier in the world, but if the size is wrong for the space, it will look weird—guaranteed.

So what are those all-important interior design rules that cannot be broken? We asked two designers at Havenly to shed light on the most common decorating conundrums, once and for all. And because we love breaking rules once in a while, we added a few workarounds too. Never visit a furniture store without these rules in mind, and your rooms will always look high-end.

Choosing a Dining Table

Interior Design Rules
Amy Bartlam; DESIGN: Jette Creative

When looking at dining room table options, it can be hard to visualize how many guests you'll be able to fit at your dinner party (or how many chairs you should buy). Havenly designer Kylee Trunck has an easy trick: "Each seat should have a minimum of 24 inches of space at the table (30 inches if you want extra elbow room). For example, a 72-inch-long rectangular table would sit three people on each side with one on each end, or—if you want to leave extra room—two on each side and one on each end. In total, you would need six to eight chairs, depending on how much room you'd like to give your guests. For circular tables, find the circumference of your table and divide by 24 inches to determine how many chairs will fit around it."

Meet the Expert

  • Kylee Trunck is a senior staff designer at Havenly where she designs innovative spaces for clients around the world. Based in Denver, she's an expert in many styles including glam, modern, midcentury, and bohemian.
  • Shelby Girard is the VP of Creative & Design at Havenly. Her work has been featured in a number of popular publications including Architectural Digest and Domino.

Break the rules: Buy a couple of extra chairs, and pull them out for larger dinner parties. If you warn your guests ahead, most people don't mind squeezing in to accommodate larger groups.

Hanging Curtains

Interior Design Tips
Amy Bartlam ; DESIGN: Jette Creative

Getting ready-made curtains to look high-end or professionally installed is incredibly difficult, but a few hints will ensure they look their best: "When hanging your own curtains, hang your curtain rod six inches wide and 12 inches high past the window frame, says Shelby Girard, head interior designer at Havenly. "This will make your windows feel larger and maximize natural light—especially in the warmer summer months when you want to let all the light into your home."

Break the rules: Never ever hang your curtains lower than suggested, but you can always go higher. Hang your curtains just a few inches below the ceiling to really give a sense of height to your room—just make sure they also reach the floor. No one likes curtains that fall short.

Purchasing Paint

Decorating Rules
Courtesy of Studio McGee

Want to order paint but not sure how many gallons you'll need? There's an easy rule for this too: "One gallon of paint will cover approximately 400 square feet," says Trunck. "Measure your ceiling height and the length and width of each wall. For example, a 10 x 12-foot room with nine-foot ceilings is about 400 square feet of wall space. Keep in mind that you'll likely need at least two coats, and get a little extra because you always end up somehow needing more than you thought."

Break the rules: Save on paint by painting only the lower half of your wall and leaving the higher half white. Your windowsills are a good guide when choosing how high to paint.

Choosing a Chandelier

Home Décor Rules
Amy Bartlam ; DESIGN: Veneer Designs

Choosing light fixtures can be a daunting process because once they're installed by an electrician, it's a pain to change your mind. Follow these simple guidelines to get it right the first time: "A dining room's fixture should be one-third to two-thirds the width of the table, explains Trunck. "In a kitchen, divide the length of the kitchen island by four to get the number of recommended pendants. In a living room, consider the size and scale of the room, as well as the height of the ceiling. Larger rooms will need a larger chandelier (or even more than one).

A handy equation is to add the width and length of your room in feet. That total would be the recommended width of your chandelier, in inches. For example, five feet plus 12 feet is 17 feet; this means you'd need a 17-inch chandelier. Bedrooms typically run around 150 to 200 square feet. Choose a chandelier between 24 inches and 36 inches to match the scale of the room."

Break the rules: Go extra big to really make a statement in a room, or swap your single chandelier for two light fixtures when dealing with an extra-long dining table.

Hanging Art

Décor Rules
Courtesy of Stefani Stein

You know when you're looking at a piece of art in a room and it just looks off? Chances are it's hung too high: "Art should be hung six to nine inches over a major furniture piece like a sofa or console table, or at gallery height—which is when the center falls at eye-level (57 inches from the ground)," says Trunck. "When choosing your art, consider something at least 36 inches wide for above a sofa. When in doubt, the bigger the better!"

Break the rules: While we would never recommend hanging art higher than eye level, you can break the rule by leaning art against the wall either on the floor or on a piece of furniture for a relaxed look. 

Picking a Rug

Design Rules
Courtesy of Stefani Stein

It's always tempting to get a smaller rug when it means saving a few hundred dollars, but interior designers know that smaller is definitely not better: "When it comes to sizing out your living room rug, the rug should be large enough to fit under at least the front two feet of your furniture, with the long side of the rug parallel to your sofa," explains Girard. In an ideal world, you would even want all legs of your furniture to fit on the rug.

Break the rules: If you've fallen in love with a rug that doesn't come in the size you need (or a size you can afford), cheat by layering the rug on top of a less expensive natural woven rug like a jute rug—that way, your rug won't feel like a postage stamp in the middle of your room.

Buying Seating

Decorating Tips
Courtesy of Stefani Stein

There is nothing worse than sitting down somewhere and not being able to fit your legs under the table or having the counter up to your chin, but these measurements often go overlooked in rooms and restaurants everywhere. "Typical seat height for dining room chairs is 18 inches and for dining room tables is 30 inches tall," says Girard. "When mixing and matching various furniture pieces, be sure to keep these general guidelines top of mind so that everyone is on an equal playing field." The same goes when choosing a barstool (30 inches) or counter stool (24 inches). Typically, unless you have an elevated bar area to your kitchen counter, don't buy bar-height stools.

Break the rules: Don't break this one; it's annoying for everyone involved. But if you must, buy swivel stools that can extend or retract to the height you need them to be.