There are visual clues that point out or indicate the age of a building. There are several clues to building age that are used by building inspectors. Primarily the building material types which include types of brick, shiplap siding, groove sheathing, cement asbestos shingle siding, plywood and aluminum siding, vinyl. The methods of building framing and type of saw cut marks lumber are all major indicators. The construction fasteners which include the beam framing, nails, pegs in post, screws and treenails. The roofing nails and other types of screws. You can also examine the existing mechanical systems along with the plumbing materials. If there is gas piping and there is a very old style of fireplace it could indicate that the property is pretty old. Especially where the construction of the chimney construction uses and older version of mortar used. Another key indicator is the types of electrical wiring used; this means if the wire types which include all other materials as well which are the panels, circuit breakers, fuses and the wires themselves are of recent type or much older in design.
It is especially important to examine the hardware. This includes the latches, door pulls, door knobs, hinges and types of hardware uses on doors and windows. Lumber width is important along with the edge finish of wooden boards in interior trim. Every building inspector must bear in mind that though one can identify typical types of construction materials and construction methods, exact dating of construction of a property remains extremely difficult. This can be due to the fact that older building materials can be reused and other components may appear old but are actually just being used due to design specifications by the architects who have designed the building. Building inspection is not necessarily a science but is fundamental when trying to determine the age of a building and the relative time of construction.