The much-quoted aphorism “God and the devil are in the details,” often attributed to Mies van der Rohe, is gospel truth in architecture. Whether it’s your house, a museum or a transportation terminal, details greatly affect both aesthetic and functional quality.

What about your house or apartment, where aesthetic and functional details may not be of museum quality?

Creative designers really sweat the details because, no matter what the building type, details contribute significantly to visual form and character while serving very important functional purposes.

Detailing begins when architects choose construction materials that are durable, sustainable, attractive, contextually appropriate and affordable. Then they focus on how these materials will be shaped and assembled.

Good designers study visible construction joints and connection patterns to create artfully composed facade surfaces, which may also include applied decorative and functional elements such as shutters or awnings.

No matter what the building type, details serve very important functional and visual purposes. (Roger K. Lewis)

A building’s aesthetic and functional quality also depend on artful detailing of built-in furnishings, special elements and appurtenances: stairs and handrails, indirect lighting, skylights, parapets and guardrails, signage, solar collectors. Hours may be spent designing how interior door frames and wall planes meet; how windows will be placed in exterior walls; and how walls and partitions will meet floors and ceilings.

Beyond its aesthetic role, sound detailing aims to make all construction components properly fit together and durably interconnect to perform as intended. Many such details are invisible after construction is completed.

Functional details ensure that structural skeletons are permanently stable; that roofs and skins are watertight, well insulated and resistant to nature’s forces; that windows, doors and related hardware operate smoothly; and that all electrical, mechanical, plumbing and other technical systems are correctly installed and safe.

And functional detailing, more than purely aesthetic detailing, is where the proverbial devil can cause trouble. Detail deficiencies, less common in institutional and commercial edifices, abound in homes and apartments.

Plumbing fixtures — bathtubs, shower stalls, toilets, sinks — may be awkwardly positioned, loosely anchored and noisy. Tilework can be poorly arrayed and grouted. Accessories such as soap dishes and towel racks may be inconveniently located and loosely mounted. Although age may be a factor, original detailing and workmanship are often to blame.

Kitchen detailing is the source of many complaints. In addition to looking tacky, cheaply crafted cabinets may be misaligned and plagued by awkward door swings and wobbly drawers. Countertop joints may widen and allow dirt to collect. With ever more plug-in appliances, badly placed and insufficient countertop electrical outlets may be a vexation. Often the biggest gripe is poor appliance layout, insufficient counter space and overly tight dimensions.

Elsewhere in your dwelling, doors may not latch when closed or fail to fit snugly within door frames distorted by settlement and wood shrinkage. Moldings and trim surrounding doors and windows, and comprising baseboards, may have warped and separated from wall surfaces. Flooring materials may be shifting, popping up, delaminating or otherwise falling apart.

Especially critical are flashing and sealants between window units and exterior wall openings or wall framing systems supporting window units. Tight, waterproof closure all along a window’s head, jambs and sill is crucial for keeping moisture from penetrating and eventually rotting wall framing, spawning mold and damaging insulation.

Like window detailing, flashing and sealing are essential for other exterior wall openings and joints, as well as roofing and roof penetrations. Buildings leak when flashing and caulking are compromised. This is typically caused over time by building deformation due to settlement coupled with flexing induced by wind, thermal expansion and contraction, and seismic movement. Expansion joints and flexible connections can minimize this risk.

Detailing well is clearly an indispensable aspect of building design. Architecture students learn a bit about detailing in school, but they mostly focus on the big picture. Only with years of practical experience designing and constructing projects — and learning from their mistakes — can they master the science as well as the art of detailing.

Roger K. Lewis is a practicing architect and a professor emeritus of architecture at the University of Maryland. His cartoons may be seen at