Matching the scale of furniture to the scale of a room is critical. A deep sectional sofa can easily overpower a small room and svelte chairs can get lost in a wide-open loft. Before you start designing, measure the length and width of each room you intend to decorate, along with the ceiling height and elements that could get in the way – stairs, columns, radiators and other obstructions. It’s also a good idea to measure window openings, along with the wall space below, above and to the sides of each one, to get ready for window coverings.
“The first mistake most people make is that they buy things that are the wrong size – sofas that don't fit in the room, sofas that don't fit through doorways, tables that are too small, desks that are too big, nightstands that hang into the doorway,” said David Kleinberg, founder of the New York interior design firm David Kleinberg Design Associates. Carefully measuring your space can help avoid such problems.