Some structures are better defined by their construction features, rather than by identification with a particular style or even building type.  These might include barns and agricultural or industrial buildings and even bridges.  Construction features sometimes are part of a vernacular tradition like notched log buildings or covered bridges, but they may also stem from an emerging technology such as  poured concrete or the use of a stuctural steel frame.   Thus, the design significance of such cultural resources is best understood by evaluating the method of construction, not the architect involved or the style represented.  While it is possible to be very detailed in describing construction features  for specific types of historic resources, for the purposes of this architectural guide, just a few of the more commonly known construction methods are included here.

PCI Construction

PCI may be constructed in a great variety of forms, reflecting the ethnic background of the builder, the materials available, the use of the barn, the affluence of the owner, and the geography of the surrounding land.  Bank barns are very common in Pennsylvania being built into a hillside to permit access on two levels.  Wagons could be pulled up to the second floor level using the slope of the hill as an access ramp. The first floor of the bank barn is used for animal pens with access doors to permit the animals to go out to pasture. The Pennsylvania Barn, a type of barn design very typical of German settlers in our state,  features a banked location with a protruding second story forebay which overhangs the first floor.  These barns often have stone foundations with stone gable ends.  Yankee barns or Connecticut barns are not built into a bank, but are free standing, two-story structures.  Usually completely of frame construction, Yankee barns are often found in the northern part of the state showing the cultural influence of settlers from New York and Connecticut in this region.   Another notable type of barn found in Pennsylvania is the brick built barn with decorative ventilators, sometimes arranged in elaborate patterns.  Open brickwork allows for the flow of air through the gable ends and may form a pattern such as sheaves of wheat, or human figures or decorative forms.  Barns are also sometimes described in terms of the nature of the joining of the support beams.  Certain patterns of beam and rafter joining reflect traditional ethnic preferences.  The type of joints, such as mortise and tenon, can also be significant in understanding the age and building tradition the barn may represent.  Frame tobacco barns with ventilator panels are also common in Pennsylvania.  These smaller barns were designed for a specific crop and use to facilitate the drying of tobacco leaves.  Likewise many agricultural outbuildings are designed to serve specific purposes.  Chicken houses, corn cribs, silos, milk houses, have common design features reflecting their use.   Some outbuildings require special siting to permit their use, such as springhouses located over springs to keep food cool, or wash houses also located over or near water for ease in clothes washing.  Root cellars of course are located underground or into a hillside to provide a lower temperature for the long term storing of food.

Stone Barns, Oley Twp., Berks County

Stone Barn and Silo, Daniel Boone Homestead, Berks County

Chimney Construction

While most houses have chimneys, the way the chimney is constructed and where it is placed on the building reflects a variety of cultural patterns or style preferences.  Historic chimneys are usually of brick or stone and may be designed so they flank the outside wall of the building which is called an exterior chimney, or so that they are located within the outside wall of the building, referred to an interior chimney.  Chimneys also may be located at the corner of the building or in the center of the building.  Sometimes a building will feature double chimneys along one  wall or perhaps both side walls.  While buildings are seldom classified solely by location of the chimney, it is a key feature in describing a building and deciding what style or vernacular tradition it represents.

Log Construction

While log buildings are often lunped together as a distinctive type of building, there are in fact a variety of different and distinct construction techniques employed in the joining of the logs.  At the corner of log buildings the indivual logs may be joined by either a saddle notch or a dove-tailed joint.  Saddle notches fit together like a saddle over a horse, with each log having a carved out section so that the logs rest snugly over one another with the round log ends protruding from the corner.  Dove-tailed log joints meet to form flush corners with each log fitting into a notched opening carved into the log below.  Dove tailing is used in the making of furniture as well to form the corners of wooden cabinets and drawers.  Most logs used for building construction have the bark removed and are shaped into a four sided, square ended form.  Thus, they present a flat surface which can be covered over with clapboard siding for a more finished look, if desired. Less commonly, the logs are left in round form with the bark attached to present a more rustic look.  This is especially true of early 20th century log resort buildings, purposely designed to look rough hewn.

Log House, Montgomery County

Log House, Mifflinburg, Union County

Log House, Delaware Co.

Industrial Complexes

Pennsylvania is a state where light and heavy industry has played a huge role in the state's develpment and prosperity.  Each of the major industries developed a standard for the production of goods, often involving the invention of types of buildings designed to make specific products.  Pennsylvania's steel mills, coal mines, factories, lumber mills, grist mills, railroad yards, glass factories, coke ovens,  iron forges, and lime kilns all required specific structures necessary for the creation of the product.  When researching or describing such  historic industrial resources, it is necessary to understand  the function of each building and to articulate specific innovations in construction that made possible such useage.   For example, a grist mill complex would feature a mill race, a mill building with a water wheel, interior milling equipment such as a grinding wheel, and perhaps a miller's residence.

Gruber Wagonworks

Udree Mill, Berks County

Drakewell Oil Refinery, Venango County

Bridge Construction

Bridges are often categorized by the type of construction technique used to build them.  Early bridges were often simple utilitarian forges accross small streams, but larger, greater capacity bridges were soon needed.  Stone arch bridges with stone wing walls and a single or multiple stone arches to the support the bridge deck were built accross the state, but in great abundance in the southeast corner.  The stone would be either mortared or dry laid, usually using native rock such as limestone.  Covered bridges likewise were built everywhere in our state and beyond, employing common bridge construction techniques such as stone support piers, wooden decking and a variety of support patterns for the roof and wall parts of the bridge.  Some covered bridges have lattice type walls and roof supports.  Covered bridges came in all sizes and sometimes appeared as "twins"  with two small bridges adjacent to one another providing a crossing over two bodies of water.  The early "Camelback Bridge" in Harrisburg across the Susquehanna River was a mile long covered bridge with a river island in the middle and a humped appearance due to the undulating roofline.     Truss bridges, forged of iron with varying patterns of joined supports are another significant type of bridge construction.  Some Pennsylvania companies like the Phoenix Bridge Company in Phoenixville were famous for their innovative  and decorative truss bridge designs.  There are various types of truss bridges-- Pratt trusses, Burr trusses, Warren trusses, Baltimore trusses, King trusses,  Parker trusses, most named for their creators or early proponents.  Poured concrete bridges came into common use around the turn of the 20th century and some of these are also considered historic due to their design or construction innovations. 

Heiniger Covered Bridge, Dauphin Co.

Sachs Covered Bridge, Adams Co.