If you are building a house or doing a major renovation, you may need to select trim molding as part of the process. Picking out trim profiles can be one of the more enjoyable tasks of the building process. Often, however, homeowners get so caught up looking at molding profiles and styles that they don't give proper consideration to proportion. If you are installing baseboard and door molding, you'll need to consider how they work together when planning their dimensions.
After several decades of trim molding taking a back seat in residential architecture, it has made a comeback with architects and homeowners. After World War II, molding became smaller and smaller as the result of the push to build houses quickly and inexpensively. Recent decades have seen the rise in the appreciation of traditional styles and more elegant living spaces. As a result, baseboards and door moldings have become beefier. Old house owners, too, appreciate the architectural boost that larger molding imparts and are often eager to replace their skimpy post-WWII trim with something more substantial.
In the old days, the scale of baseboard and door trim followed the size of the room. Large rooms with tall ceilings received big trim in consideration of their size and the importance that the homeowner placed on the room. Smaller houses were trimmed out more modestly. While much different in size and expense, baseboards and door trim in both mansion and cottage were always in scale with each other.
If you opt for standard 2 1/2-inch door molding, standard 3- or 4-inch baseboards are going to be too skimpy. Five or six inches would be more in scale. If you are using beefier 3 ½ or 4 1/2-inch door trim, 8- or 10-inch baseboards are more appropriate. Keep in mind, also, that the outside edge of the door molding has to be deep enough to accommodate the thickness of the baseboard. Plinth blocks at the base of door molding can bridge door trim and baseboards that are incompatible in thickness.
When selecting molding, make sure the molding and baseboard match in style. Simple trim should be paired with simple baseboard, fancy trim with fancy baseboard. If upgrading molding in a modest house, resist the temptation to "tart up" the house by installing complicated molding with intricate detail. Increasing the size of the molding goes a long way toward adding architectural interest to a room without making it look like a child in grown-up's clothing.