One of the most common mistakes made by homeowners when doing their window treatments is getting the proportions wrong. There is a difference between scale and proportion. Scale refers to the size of an object compared to the space it's in. Proportion is about relationships.

Are the different elements of a room or window in harmony? One of the first things to consider when designing window treatments is the proportion and scale. For example, a room with large windows and large scale (tall ceilings and/or a large room) looks best with larger proportions. Your top treatments, swags, drapery panels and other fabric treatments will look best if they are proportionally scaled to the larger size.

How to Scale Top Treatments?

A designer or Window Treatment Professional would first evaluate your window to determine if it is harmonious in scale (size) and in good proportion (relationship) to the room. You do that by considering the following factors; the height of the ceiling; the number of windows in the room; the presence of mouldings; the proportions of the windows; the pattern in the fabric (if any); or the desire for light and, most importantly, personal preference. Custom window treatments can alter these proportions, making your window look taller, wider, longer, or all of these, by draping the wall beyond the window frame in each direction. For the hobbyist, a good rule of thumb for top treatments (valances and swags) is that they are commonly designed to be one-fifth to one sixth of the total treatment length, or 15 to 20 per cent of the room height. So, if your drapery's finished length is 100", you can have a valance of 16" (1/6") to 20" (1/2") long. If you want to make the room appear taller and you have space above the window to mount, then you can make the top treatments longer and mount higher above the window.

Cornices or pelmets should be mounted to one-sixth of the total treatment length, but can also go a little higher, dependent on the ceiling height. Please note that the proportion of the cascades or tails should be at least twice the length of the swag. Bathroom windows, which are usually in small rooms, look best in smaller size scales, and so top treatments can be scaled down to fit the room. Drapery panels are commonly hung 1-2" above the window casing (the exposed trim moulding framing around window). If there is no window casing, a minimum of 4" above is preferred. If you have the space above, the panels can be hung higher to make the room appear taller. It looks a little awkward to go above 5-6" from the casing. In general, drapery panels make the room appear taller (if properly mounted above the window). The vertical lines of the draperies add a visual height to the room as compared to a horizontal top treatment.

How to Scale Panels?

Another common mistake is skimpy panels. When using rod pocket panels, they should always be 2 ½ to 3 times the width; tab-top and grommets styles should be 1 ½ to 2 times the width of space. When designing pleated drapery panels for a large and tall window, skimpy one width drapery panels will not accent the large scale of the window. Two-width panels will keep in scale with the room/window size. One width of 54" fabric pleated down to 18" is usually not enough for side drapery panels, unless the windows are quite small. For most windows, 1 ½ widths of fabric will make a more pleasing panel, and for two storey windows, at least two width are need.

Acceptable practices of drapery proportion and scale are not always followed in today's design world. It is predicated on what the homeowner wants first and foremost, but in the absence of special requests, there is a rule of thumb for almost every situation.

Tips to remember

a Top Treatments are always one fifth (1/5) to one sixth (1/6) the total treatment length.

a Drapes hung above window should be at least 4" above the window

a When using decorative rods you may extend 4 to 12 inches above the window

a Do not skimp on panels. Rod Pocket treatments should have a minimum fullness of 2 ½ times width.

a Window treatments must be appropriate to a room: not overdone in a small room, and not skimpy in a room of grand scale.

Train your eye for scale and proportion, and it will be a useful tool in everything, from gardening to cooking to fashion and, of course, home decorating…Enjoy!