Post-and-beam construction: lasting quality. From Japan's Golden Hall to an invincible New England barn

Ted Benson remembers vividly the day several years back when he tried to demolish an old New England barn. He couldn't! The now-recognized expert in post-and-beam construction recalls how the barn, with three-quarters of the underpinnings removed, still didn't collapse. It merely ''sagged a little,'' as he puts it. So he attacked it (his words) with a chain saw until he believed he could pull it down with a stout cable and a borrowed wrecking truck.

Still the barn resisted. So Mr. Benson had no option but to dismantle it piece by piece.

At first the old barn appeared to be frustrating him at every turn, but soon he realized it was doing something much more important than that. It was sending him a message, telling him something about durable construction practices. It was a message the Alstead Center, New Hampshire builder was ready to hear.

As a builder of tract houses in Oregon, Mr. Benson had worked for a man whose definition of a good carpenter was someone who could drive home a 16-penny nail with one blow of the hammer. Those who took two blows were worth hiring, but no one else need apply. Housing that went up that fast could also come down easily, the builder recalls, which is why the old barn's resistance, even to a wrecking truck's onslaught, came as such a surprise.

As it happened, not a single nail held the barn's timber frame together. The huge beams were spliced with mortise-and-tenon, tongue-and-fork, dovetails, and other joints, all locked in place with stout pegs of oak. It was joinery at its centuries-old best, and Mr. Benson was filled with admiration for both the craft and the craftsmen involved.

Later, as he stood in England's Westminster Hall and looked up at the vaulted ceiling, that admiration became something akin to awe. The roof area spanned 60 feet without a single supporting column, even though no timber used in the construction measured more than 20 feet in length.

Post-and-beam construction is an age-old technology that reached its peak some 600 years ago, but it is one that is also ''most appropriate to the late 20 th century,'' Mr. Benson contends.

Timber frame joinery, often referred to as post-and-beam construction, is the use of widely spaced heavy timbers to form the structural framework of a house rather than the closely spaced, light timbers of the more modern stud or ''stick-built'' house. It gains its strength and durability from far more than just heavy timbers. Joinery makes the difference.

Joinery is the science - or art, if you will - of simple but precise cutting and chiseling that makes it possible for one timber to lock into another, somewhat the way jigsaw-puzzle pieces fit together. So while the stick-built frame, which is merely nailed together, has to be covered with plywood or boards before it becomes rigid, the heavy, joined frame can stand alone.

Put another way, the exterior of a post-and-beam house can deteriorate without compromising the structural integrity of the building. Like the stout oak chair that only needs occasional recovering, the properly constructed post-and-beam house would merely need recladding once a century, or even less frequently, to be completely renewed.

British timber-framing technology was the first to cross the Atlantic, but it was quickly followed by German, French, and Scandinavian ideas that were all added to the construction melting pot. So while post-and-beam technology in the United States is totally European in origin, ''the blend is uniquely American,'' Mr. Benson points out.

Plainly, joined, heavy-timber construction survived for more than a thousand years (Japan's Pagoda and Golden Hall, still standing today, were built in AD 693 and 697 respectively) because it produced attractive and very durable housing.

So why did the practice begin to wane a century ago? There are probably several reasons, but two stand out. An increasingly mobile society saw little need to build a house that would stand through their grandchildren's and great-grandchildren's lives when the likelihood of even their children staying in the same part of the country seemed remote. In addition, as the pace of life picked up, speed of construction surpassed durability in importance.

Under these circumstances, the time involved in crafting a quality joint was deemed inefficient. A stick or stud-framed house can be built in as little as 30 days, but it will not, nor is it expected to, last through the next century without considerable reconstruction and repair work. By some industry reckonings , the life span of a modern house is no more than 50 years.

Now, according to Mr. Benson, trends are changing. Labor and materials are becoming increasingly expensive; the cost of borrowing money, almost horrendously so. As a result, he says, ''People are becoming concerned that their investment should not be squandered on poor-quality buildings.''

Then, too, space-age inventions are lending themselves to this age-old technology.

The sturdy timber frame can now be clad with insulating panels, and the combination is a building that performs better than anyone previously dreamed. Cranes also mean that a small crew can now erect the timber frames, or bents as they are called, that previously required the combined muscle of an entire community.

Ironically, this age-old technology lends itself well to the present trend in solar heating. The sturdy and widely spaced supports allow for the inclusion of large areas of sun-facing glass. Open interior designs are possible because interior walls are not required to support the roof. This, in turn, makes it simple for sun-warmed air to move freely to all corners of the house.

Mr. Benson maintains that a post-and-beam home need not be more expensive to build than a conventional one. But, he points out, ''when most owners see how good the exposed solid oak timber frame looks, they tend to go for matching hardwood floors and top-of-the-line kitchen cabinets, etc.'' These high quality ''accessories'' raise the price. On the other hand, there are builders who use pine or other soft woods for the frame where matching floors and cabinets would be less costly.

When Ted Benson realized that post-and-beam joinery was the way to go, he searched for literature on the subject but could find none. Actually, the craftsmen of old had left the detailed instructions for their craft in the many old buildings that still stand today. It was the need for this type of instruction that took him to England's Westminster Hall, to the remarkable stave churches of Norway, and to other parts of Europe. In addition, those remaining Yankee barns also had much to tell him.

Now, after seven years of refining his craft through building post-and-beam houses and teaching the art of joinery, he has written a comprehensive manual on the subject with James Gruber, a civil engineer. ''Building the Timber Frame House'' (Charles Scribner's Sons, New York, $13.95) was written so that others will not have to travel the world to learn about the craft they wish to master.

Ted Benson also teaches a hands-on course in post-and-beam construction at the Cornerstones Energy Group in Brunswick, Maine. Others among the growing number of owner-builder schools, including the Shelter Institute in Bath, Maine, also offer such courses. A list of all the owner-builder schools in the US is available for $2 from Home Again Publishing, PO Box 421, Village Station, New York, N.Y. 10014.

Increasing numbers of construction companies now build post-and-beam houses. Some will erect the frame, exterior walls, and roof, leaving the interior to be completed by the owners. At least one company offers post-and-beam kits for the homeowner to erect.