CAD: The Good and the Bad

Not so long ago, a well-equipped architect might have had the following items on his drawing board: A tee square or parallel rule; a couple of plastic drafting triangles; some templates for drawing circles, door swings, and the like; and a container bristling with an array of mechanical pencils. A really up-to-the-minute fellow might even boast an electric erasing machine, to help fix all the errors that inevitably cropped up as hand-drawn plans wound their way to completion. 

Today, of course, every one of these items is utterly obsolete, right down to the pencils--all swept away by the advent of computer-aided drafting, or CAD.  CAD produces invariably flawless lines, along with perfect lettering in any font or size. As for erasing, it’s now done quickly and spotlessly by tapping the Delete key. Hence, the drafting skills so diligently practiced by architects of my generation now rank roughly on par with the making of stovepipe hats. 

If you’re expecting a lament over the loss of the good old days, however, you won’t find it here. Computers have been an indisputable advance over the tedium of hand drafting, speeding the work and improving its quality by making changes and ccorrections so much easier. In the past, even minor revisions to a set of hand-drawn plans could involve hours of painstaking erasing and redrafting. With CAD, they may take only minutes. So dramatic is this shift from hand drafting to CAD that my own recollections of toiling at the drafting board--hands, arms, and elbows smudged in graphite and clothes dusted in eraser crumbs--now seem downright Dickensian.

Yet while CAD has revolutionized the production end of architectural practice, it has done surprisingly little to further the architect’s creativity. Instead, the computer has introduced a subtle yet unmistakable pressure on architects to design within its own parameters. CAD programs excel at drawing orthogonally and at copying and pasting, making it a cinch to churn out rigid designs with lots of repetition. However--heroic Frank Gehry-type exercises notwithstanding--most CAD programs remain clumsy and exasperating when asked to produce the sort of freeform work an architect of yore could conjure in seconds with pencil and paper.

Nonetheless, we architects seem to feel compelled to use the vast computing power at our disposal, and we often find ourselves spending dozens and sometimes hundreds of hours creating complex digital views of projects that might have been just as well conveyed by a quick pencil sketch.

As surely as CAD has liberated architects at the production end of the business, there’s little doubt that, consciously or not, many of us have also been constrained by its steely precision. It would be a rare CAD practitioner, for example, who could elicit the sort of lyrically patinated Spanish Revival work of an Addison Mizner, or the serpentine, near-caricature Storybook compositions of a William R. Yelland. Revisiting such pre-CAD masters quickly makes clear that in the most fundamental realm of architecture, the free exercise of the imagination, CAD still provides more encumbrance than encouragement. 

EXPLETIVE DELETED

The other day I was eating breakfast at a cozy little diner called Sam’s Log Cabin, not far from where I live. The place is pretty much what its name suggests--a rustic little box of a building with log siding and a hipped roof. The inside is just as spartan as the outside: there’s no proper ceiling, and the roof rafters are plainly exposed to view. 

I was savoring my pancakes and bacon, idly regarding the unusual construction, when my eyes came upon a curious thing. Apparently the person who’d framed the roof made a whopping mistake and ended it in the wrong location. You could see where the angled hip rafters were framed in, as if the carpenter thought he’d reached the end of the building, and where additional rafters had been appended to continue the roof another eight feet or so. It was clear that this had happened at one time, because the next stage of the work--the boards covering the roof--plainly continued onto the patched-on part.

The intriguing thing wasn’t the error itself--in construction, mistakes happen all the time. Rather, it was that the evidence was still right there in front of everybody, frozen in time, so vivid and immediate that you could practically still hear the expletives bouncing off the rafters.

Compelling architecture, whether magnificent or mundane, seems to have a common property--an ability to record and reflect the traces of human presence. In a great Gothic cathedral, for instance, the original builders may speak to us through a skillful piece of joinery, a beautiful carving, a radiant expanse of stained glass. What’s more, we sense the presence of all those who’ve entered--the generations whose passage has worn a stairstep smooth, or whose grip has polished a bronze handle to a brilliant patina. 

But magnificent buildings aren’t the only ones with this property. Humble ones--a barracks, a barn, or a quirky little restaurant--can have it as well. And sometimes, the thing that engages us is nothing more remarkable than a plain old mistake.

That, after all, is what lured me from my pancakes into a reverie about what happened on the day that nameless carpenter framed the roof of Sam’s Log Cabin. Did he have something else on his mind--a sick child at home, an argument with a friend, an overdue rent payment? Or did he just down a few too many for lunch? 

We’ll never know for sure, but in any case, the exact hows and whys don’t matter. What matters is the momentary kinship with that person-- perhaps long gone--who was probably not so very different from us, and who has reached across time to give us a metaphorical nod of recognition. Sometimes that person touches us with beauty, and sometimes, as in this case, through a personal foible of the kind we’ve all experienced. Either way, the inert matter of architecture has briefly assumed the power to remind us of what it means to be human. Two pancakes, two eggs, two strips of bacon, and a quick lesson in humanity--not bad for $6.95. 

WORDS THAT PACKED A WALLOP

While much of the verbiage architects have churned out over the years has deservedly been forgotten, a number of phrases have managed to encapsulate, if not outright inspire, entire architectural movements. 

Among the best known yet least understood of these is Louis Sullivan’s “form follows function” (though to be precise, his actual words were “form ever follows function,” and he borrowed the phrase from the American sculptor Horatio  Greenough). Sullivan’s point was that, in architecture, practical need invariably trumps aesthetics  Yet subsequent generations of modernists often took these words to mean that anything nonfunctional--more specifically, ornament--had no place in architecture, period. Ironically, Sullivan, whose exquisite and highly personal style of ornament remains unmatched by any American architect before or since, would have been loathe to have his words inspire countless blank-walled buildings.

In 1908, the Viennese architect Adolf Loos penned an essay famously titled “Ornament and Crime,” whose English translation of 1913 opined: “The evolution of culture marches with the elimination of ornament from useful objects.” As extreme as this statement sounds today, it’s wise to remember it was made in the wake of a wearying half-century of bombastic Victorian architecture. No wonder Loos’s words struck home with rebellious young architect of the World War I era, inspiring a generation of architectural works both brilliant and barbarous.

Le Corbusier, another architect with a penchant for sweeping pronouncements, is widely credited with this humdinger: “Architecture is the learned game, correct and magnificent, of forms assembled in the light.” It’s an especially curious inspiration for architects, since it manages to completely overlook architecture’s fundamental purpose--that of enclosing volume.

“Less is more,” Ludwig Mies van der Rohe’s immortal entry into the architectural lexicon was, like Sullivan’s, often used by lesser talents to justify an architecture of nothingness and boredom. Oddly enough, another of Mies’s better-known phrases, “God is in the details,” would seem to state just the opposite of “less is more”--but perhaps what Mies really meant was that what little remained after being made “less” had better be awfully good. 

A generation later, Robert Venturi, among the first architects to declare Modernism an emperor with no clothes, ably countered Mies with “Less is a bore.” The Postmodern movement he spawned took these words to heart as fervently as had Mies’s followers the original--sometimes to good effect, sometimes not.

Of course, no A-list of architectural quotes would be complete without a few entries by Frank Lloyd Wright. At his most thoughtful, alas, Wright tended toward flowery, nineteenth century-style prose bereft of sound bites--one reason his terse insults seem better known than his architectural philosophy. However, one quote Wright made late in life not only proved good counsel to architects everywhere, but quickly entered the vernacular. In 1953, he told New York Times Magazine, “The physician can bury his mistakes, but the architect can only advise his clients to plant vines.” 

And on that note, a Wrightian comment to inspire architects and columnists alike: 

“I'm all in favor of keeping dangerous weapons out of the hands of fools. Let's start with typewriters.”

A LABOR OF LOVE

Some years ago I was walking through an old Victorian house that was being renovated. In one room where the original wall framing was exposed, I found a curious bit of workmanship. One of the two-by-four studs had been carefully notched about halfway up, and a small hardwood wedge had been driven in. After a moment’s study, the reason became clear: the two-by-four had been badly bowed, and rather than cutting it up for some lesser purpose, the Victorian carpenter had used an age-old but effective trick to make it straight again. Then he’d installed the mended stud in the wall along with the rest.

Why all this effort to save a single stick of lumber? The answer demands some historical context. In Victorian times, labor was cheap, but building materials were not. Hence, a carpenter would think twice before tossing out a crooked two-by-four if a few minutes work could make it useable. The carpenter’s time, after all, was a trifling expense compared to the cost of that two-by-four.

Today, the situation is exactly reversed. Lumber and many other building materials are relative bargains compared to the cost of labor, which typically consumes at least two-thirds of the building budget. Hence, a modern-day carpenter wouldn’t bother fixing a crooked stud because, given his hourly wage, the time he spent would easily exceed the value of the lumber he was saving.

There’s no doubt that this situation often leads to unnecessary waste, because it’s ultimately cheaper to use extra material if it speeds up the work. For instance, a hefty 4-by-12  header is typically installed over windows and doors even when it’s structurally unnecessary, simply because it takes less time to install than numerous smaller pieces of lumber. 

On the bright side, though, escalating labor costs have actually forced the construction industry to become faster and more efficient. Among the earliest labor-savers were fully pre assembled windows, which arrived in the 1930s (previously, windows were built on site, either from stock parts or entirely from scratch). 

The construction exigencies of World War II spurred another great labor saver--gypsum wallboard. So-called “drywall” did away with the tedious process of wet plastering, which entailed nailing up thousands of feet of wooden lath, applying three separate coats of plaster, and waiting for days while each coat dried. 

After these developments came pre-hung doors, manufactured roof trusses, modular cabinets, and all the other prefabricated components so important to reducing onsite labor. There’s no doubt that mass-producing components in a purpose-built factory, immune from weather, dirt, and damage, is more efficient than building them onsite. The only downside is a subtle but unmistakable aesthetic change: As houses increasingly trend toward being mere assemblies of manufactured items, most of what meets the eye--windows, doors, cabinets--has the unvarying consistency you’d expect from mass-produced products. 

Hence, there’s less and less distinction among houses, and fewer and fewer traces of the individual prerogative that was a hallmark of hand craftsmanship. This, I suppose, is the price we pay--for the prices we’re paying.

ARCH-ITECTURE

If you’ve ever seen a picture of Stonehenge, the prehistoric monument near Salisbury, England, you’ll recognize the structural system known as post and lintel. It consists of two upright blocks--the posts--with another block--the lintel--spanning the gap between them. This was the earliest type of structure used to span open space.

The trouble was, the widest distance you could span with a post and lintel was limited to the size of the biggest stone lintel you could get your hands on--not to mention lift into place. Hence, even the grandest ancient buildings under roof--Egypt’s vast temple at Karnak, for instance--were little more than forests of stone columns with narrow passages left over in between. 

The invention that finally overcame this problem was the arch. It had humble enough beginnings. It was already known to the Babylonians, Assyrians, Greeks, and others, often in the form of a roof over underground drains. Yet the Romans were the first to really exploit its unique structural properties. They recognized that, unlike a lintel, an arch could span distances much greater than any single block in the structure.

Here’s why: A stone lintel carries a load by bending infinitesimally, which compresses the upper half and stretches the bottom half. Now, stone is strong under compression but fairly weak under tension, so the lintel has to be really deep relative to its span or it may crack.

An arch works differently. Because the wedge-like stones are arranged in a circular shape, placing a load on top squeezes the blocks against each other, compressing them but not putting them under tension. This takes much better advantage of the strength of the stone, and hence requires a lot less of it to do the job. 

Of course, an arch can’t just stand up by itself--something has to brace it on either side to keep it from spreading apart under load. Usually, a bit of solid wall serves this purpose. But you can also put a series of arches side by side to form a continuous arcade, letting one arch brace the next, as in the elevated Roman aquaduct known as the Pont du Gard near Nimes, France. 

Arches form the basis of even more useful structural systems, though. By stretching an arch into a tunnel shape you get a vault, an early means of roofing over space without needing intervening supports. By intersecting two vaults at right angles you get a groin vault, which the Romans used to roof their monumental Baths of Caracalla, among other things. And if you rotate an arch about its centerline, you get a dome--the basis of some of man’s greatest architectural works, from Rome’s Pantheon to Istanbul’s Hagia Sophia.

Ironically, since modern structures are now seldom built of masonry blocks, true arches are rarely used anymore except for dramatic effect or, occasionally, to support bridges, trestles, and the like. What’s most commonly used instead? Why, it’s our prehistoric pal, the post and lintel--though nowadays it’s made of wood, steel, or concrete.

PAST PERFECT

A contractor once told me an interesting story about a house he’d built for a man in Connecticut. Winter was already setting in when he’d gotten the place weather tight, so as soon as he finished the fireplace, he built a fire in it to keep the house warm. When the owner found out, he demanded that the contractor tear out the bricks inside the fireplace and replace them because they’d gotten sooty. He told the contractor that he was paying for a brand new fireplace, and he was damned well going to get one.

This brought me back to a paradox I’ve pondered from time to time. When some people build, they become obsessed with getting everything absolutely perfect. It’s not uncommon for owners to have brand new materials ripped out again because they’ve picked up a tiny scratch or a little ding somewhere along the line. This happens even with materials predestined to show age or wear from normal use--say, hardwood flooring, painted trim, or in the case of our unlucky contractor’s client, the inside of a fireplace. 

What’s odd about this obsession with newness and perfection is that the sort of buildings we seem to admire most--Europe’s storied old cottages, let’s say, or perhaps China’s ancient courtyard houses--are precisely the ones that are old and thoroughly beaten up, with a patina that bespeaks their many years of history. And “patina”, after all, is really just a nice word for the flaws that arise from age and use--if anything, it’s a sort of anti-perfection. And given that we covet the patina of age in old buildings, why do we place so much value on flawlessness in new ones?  

In architecture and construction, quality--soundness, durability, and fitness of purpose--is never negotiable. On the other hand, we’d lose very little in easing our compulsion for flawless surfaces. For one thing, time and Mother Nature never allow us the pretense of perfection for any length of time--something modernist architects have usually learned the hard way. Better to start with the assumption that our work will get a good thrashing over time, and design accordingly. 

One way to do this is to use materials that don’t demand a high degree of finish: Oiled wood, rough plaster, wrought iron, to name a few. Better yet are materials requiring no additional finish at all: Natural wood, stone, brick, textured concrete, clay tile, weathering steel, and tinted stucco, among others. Beside requiring negligible maintenance, all of these materials can absorb years of abuse, and in return just keep looking better and better. 

Take a look at much of today’s architecture, though, and instead of materials that improve with age, you’ll find mirror-polished surfaces, razor-sharp corners, and demanding and intricate finishes. Seeing these flawless designs in photographs, forever protected from the indignities of daily use, it’s no wonder so many of us have come to expect flawless results in our own projects. To this rarefied school of design, I suppose, a soot-blackened fireplace would indeed be seen as a thing that’s ruined and imperfect, instead of being testament to a human tale unfolding. 

HOW NOT TO GET TO YOUR FRONT DOOR

Here's a textbook example of how NOT to reach your home’s front entrance. A while back, I came across this otherwise rather charming house that was set back quite a distance uphill from the street. 

Alas, this is how you got to the front door: Assuming you even noticed the narrow flight of concrete steps hidden among the shrubs and didn’t clamber up the driveway instead--as most baffled visitors did--you were rewarded with an additional hike over uneven and badly-spaced stepping stones that drifted aimlessly up the hill. At the last minute, the route swerved to avoid a huge tree and then just barely squeezed you in at the foot of another narrow, L-shaped stair.leading up to the front porch. 

Climbing up to the first landing got you an excellent closeup view of the electric meter, the gas meter, and a tangle of assorted power and telephone lines, along with the corresponding paraphenalia belonging to the neighbor’s house. A final flight of steps to the left aimed you straight into a spiky, towering juniper bush, enroute to which you might just happen to notice the actual front door in a recess to your right.

So let’s look at each of these problems in turn:

• The beginning of your entrance approach should always be clearly discernible from the sidewalk. If it isn’t, call attention to it with a lamppost, a mailbox pylon, a gate or some other distinguishing feature. The approach should also be entirely separate from the driveway, so that people don’t have to pick their way around parked cars and oil stains to get to your front door.

• Outdoor stairs and steps need to be both broader and shallower than the ones used inside a house. Make them at least six feet wide, and even wider if appropriate. Stair risers should be no more than six inches high, and treads no less than eleven inches deep. Traditional porch steps can be a bit steeper, but in general, the easier the climb, the better.

• Your entrance path should follow a clear, rational course. If you’re after a formal approach, derive your layout from just a few basic geometric shapes. For a more naturalistic result, combine no more than one or two strong curves, and avoid feeble, tentative changes of direction--you cannot get a picturesque effect just by making your approach meander aimlessly. Avoid a layout that points people toward immovable objects like trees, bushes or blank walls--a path in nature invariably winds between obstacles, not directly toward them.  Above all, whether your approach is formal or informal, don’t make the layout too complicated, or it’ll lose its visual power. 

• Lead people past the best features of your front yard, not its worst ones. Consider potential vistas from various angles, ways to showcase favorite plants, opportunities for benches or other stopping points, and the possibility of water or arroyo features, however modest. Conversely, avoid routes that look onto gas and electric meters, garbage cans, garage doors, heat pumps, and other utilitarian features.

• Lastly, make sure the final leg of your entrance approach points people clearly toward the front door, and nowhere else. This is especially important if there are patio doors or other exterior doors nearby. There should never be any doubt about which door is the entrance.