Sketch of basic architectural house styles with common period dates How to Determine The age of a building
Visual & Other Clues Tell Us Building Age or the Age of its Components & Systems

  • AGE of a BUILDING - CONTENTS: How to determine the age of a building - Building component age: construction materials, methods, including hardware, saw cuts, and other details can help determine when a building was constructed or when it was modified.
  • POST a QUESTION or READ FAQs about how to determine the age of a building or home or its components & systems

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

How old is my house? This article series provides a photo guide to determining the age of a building by examination of the architectural style of construction or the building materials and components that were used in the structure. Here we list some helpful clues to answer the question "how old is the house?" and we provide photographs of key visual clues useful for determining the age of a building.

The age of a building can be determined quite accurately by documentation, but when documents are not readily available, visual clues such as those available during a professional home inspection can still determine when a house was built by examining its components, building materials, even nails, fasteners, and types of saw cuts on lumber.

Our page top photo shows a Mid-Victorian multi-floor structure built in Hudson, NY, USA ca 1874. The entire building exterior facade is made of cast iron, including the window parapets and sills and the faux stone exterior walls and corner quoins.

Green links show where you are. © Copyright 2015, All Rights Reserved.

How to Determine The age of a building - A List of Visual and Documentary Clues Provided by a Home Inspection

Sketch of basic architectural house styles with common period datesVisual clues pointed out by a home inspector or available to any careful building inspector can help indicate the age of a building.

Article series contents

Clues to building age include these examples which we expand and detail in text and articles below and listed at the left of this page.

Keep in mind that even when we can identify specific types of building materials and building methods, precise dating of the time of construction of a building remains difficult: old building materials were often re-used, so beams, siding, and other components may appear in a building built later than when the materials were first made.

Also, in the U.S. various states had machines for making cut nails, screws, and sawmills at different times. For example, New York State was industrialized earlier than some western or southern states, so machine-made nails appear earlier in New York than elsewhere.

Photo Examples of Architecture & Style Providing Typical Dates of Construction

While building architectural styles such as "Victorian" continue to be built into the present, the combination of a recognizable architectural style with an inspection of the building materials which have been used provide considerable information about the age of a home as well as its history of changes and additions.

See ARCHITECTURE, STYLE, & Building Age for photographs of buildings in North America and Europe demonstrating various architectural styles and dates.

Guide to Using Building Records to Help Determine the Age of a Building

Suffolk Resloves House © Daniel FriedmanThis article explains and list examples of source of public records that can help determine the age of a building. Because the office where building records are held will vary by name and municipal authority, the exact name and location of building records in your community will vary from those examples shown here.

Sources of public records to assist in determining the age of a building

  • As suggested by reader Kathy Bohon, call your county Recorder of Deeds and inquire when the property was placed on the tax rolls. The date of construction can be 1-3 years prior or in some cases, much earlier if records are incomplete.
  • Local town, county, or even state or provincial (in Canada) tax records may indicate the original date of construction of a building
  • Historical records containing real estate listings include indications of building age
  • Census records can indicate that a building was present at a particular address at the time the census was taken.
  • Papers found in the building itself, its archives, will often indicate when the building was present.
  • Notes and annotations written on the building itself may indicate dates of its age or modification. When we renovated a neo-victorian house in Poughkeepsie, New York we found, on removing aluminum siding, that the siding installers had written their names and the year that the siding was installed (1960).
  • Historic homes that are in a national, state, or local historic register may include a plaque (photo above left of the Suffolk Reserves House of 1774) as well as extensive documentation in local historical records.

    The Suffolk Resolves house (located in Milton, Massachusetts and placed in the National Register of Historic Places in 1973) whose plaque is shown above documents the Suffolk resolves, a statement of colonial animosity, signed 9 September 1774 and ultimately leading to the United States Declaration of Independence from Great Britain in 1776. Such a home is of course well preserved and documented.

Some examples of conditions that confuse dating the age of a home include

  • The original home may have been substantially modified, renovated, or a large addition may have been built abutting or even overlaying the original structure.
  • The home may have been brought to its present site from another location.
  • The home may have been built on the site of an earlier structure of which no components remain, or sometimes, portions of the foundation of the original structure may be in place but nothing else, for example after a major fire.

Readers are welcome to Contact Us by email to suggest other locations of records that help document the age of a building and the date of its original construction.

Chimneys & Fireplaces as Indicators of Building Age

PHOTO of a single wythe unlined brick chimnney flue

Here is a photograph of an unlined single wythe brick chimney on an 1856 home in New York State.

The location, size, shape, building materials, and use of chimneys on buildings offer good details aiding in estimating the age of a building.

These details can also indicate where additional safety inspections or perhaps repairs or updating are needed for safe use of a chimney, fireplace, building heating system, or wood stove.

CHIMNEY MATERIALS vary among none (a hole in a roof), brick, stone, masonry block, metal flues, insulated metal chimney flues, and wood-framed metal flues on buildings.

Three different colonial era homes were common in America. Early homes of one room included a chimney at one end. Second were homes that had a chimney at either end, consisting of two rooms with (or without) an entry between them. The third group used a central chimney placed between the two rooms and provided a fireplace in each room. Earliest of these homes were only one-room deep; later they grew to two rooms deep. -- Isham.

Details about chimneys, flues, fireplaces, woodstoves: see CHIMNEY INSPECTION DIAGNOSIS REPAIR

Doors & Door Hardware as Indicators of Building Age

Details about doors and examples of how they can help determine the age of a building are at DOOR HARDWARE AGE

Electrical Components as Indicators of Building Age

PHOTO of an obsolete 30-Amp electrical meter and fuse panel ca 1935

Here is a photograph of an obsolete 30-Amp electrical meter and fuse panel, ca 1935.

While varying somewhat by area of the country in the U.S., Latin America, Europe, and other areas, there are recognizable generations of electrical wiring ( KNOB & TUBE , greenfield, armored cable or " BX" wiring, plastic or " NM/NMC" wiring), wiring materials (copper, tinned copper, aluminum, copper-plated aluminum), and also, easily recognized generations of electrical meters and electrical service panels.

Here we illustrate various of these materials and products and we provide information about their safety or about the need to inspect or perhaps replace or upgrade certain problem equipment. See:

  • ALUMINUM ELECTRICAL WIRING, although it may have made earlier appearances, was used extensively in new construction in North America from about 1967 to 1975, probably in response to a spike in copper prices, and ending as the fire hazards of aluminum wiring became widely known. Presently solid conductor aluminum wiring is not used in new construction but multi-strand aluminum wiring is still in use for service entry cables and single-appliance high-amperage circuits such as air conditioners and electric ranges. (Overheating and connection failures occur with multi-stranded aluminum wiring too.)
  • ARMORED CABLE - BX, metallic-sheathed electrical cable was first introduced in 1896 and continues in use in modernized form (with better conductor insulators) today. The earliest armored cable wiring used only paper inside of the insulating steel jacket, a material that failed when the wire was wet or was flexed excessively. Later generations of armored cable used rubber-insulated and fabric covered conductors.

    We find lots of rubber-insulated armored electrical cables in U.S. homes dating between 1920 and around 1940. Beware of this older armored cable: often the conductor insulation is deteriorated and unsafe, particularly close to electrical lights and other connections where heat may have been present. We've successfully repaired and kept such circuits in use by cutting back the damaged overheated length of wire. Modern BX wiring uses plastic insulated conductors and is available in a variety of wire gauge s and number of conductors.
  • Electrical receptacles and device power cord plugs have varied in design and features over the history of electrical wiring;
    • Un-polarized electrical receptacles: Early electrical receptacles were (and are) usually two-prong, with each receptacle slot of equal size, and with no ground connection for the power cord that is plugged into the receptacle
    • Polarized electrical receptacles: Electrical receptacles were changed to require proper polarity of electrical connection between the receptacle and the connecting appliance or device cord by making one of the receptacle slots wider and the corresponding power cord plug spade wider than the other. These un-grounded (or unearthed) electrical receptacles (some people call them electrical sockets or wall plugs) are still in use and should still be installed if the electrical circuit to which they are connected does not provide a ground path.
    • Grounded electrical receptacles: Most modern electrical receptacles (power outlets, wall sockets, wall plugs) provide a combination of polarized connectors (one slot wider than the other) and a ground connection (the rounded opening below the center of the two spade connectors).

      The most common electrical receptacle used in homes in the Americas, Japan, and some other countries is the 15 Amp (#14 copper wire circuit) receptacle described as NEMA 5-15 15 A/125V electrical outlets. If the receptacle is properly installed with the ground connection "down", the wider slot on the left accepts the neutral connection of the power cord and the more narrow slot accepts the "hot" connection of the power cord.

      Beginning with the U.S. 1992 electrical code, special versions of grounded electrical receptacles may shift the pattern of the spade connector slots to provide receptacles that accept both 15A and 20A power cords and others which rotate one of the spade connectors to 90 degrees from the other, to accept only 20A power cords.
    • European electrical receptacles in modern form (2008) use the CEE 7/16 electrical socket and matching wall plug with openings 19 mm apart and 4 mm in diameter, and that usually does not include a ground connection.That's because european residential electrical circuits are designed for 240-volt circuits (both wires to the receptacle are "hot" and the power cord plug can be inserted in either position. These receptacles are designed for 2.5A/240V circuits with no ground path. A grounded version of this wall receptacle is used in the U.K. (BS 4573) and is called the UK "Shaver" receptacle.
    • European electrical receptacles of an older design and still found in many buildings in the U.K. and India use a three prong 5-amp 240V BS 546 plug (one is for ground) or a higher capacity BS-546 "M" receptacle rated for 15 amps. The older British 3-pin 13-Amp line cord plug and matching wall receptacle (BS 1363) first saw use after WW II in 1946 and is still found in the UK and some other countries and has two flat 240V pins and a single vertical ground pin connector.
    • Different electrical receptacles and line cord connectors are used in France (Type E -pin with a female connection to ground (earth) on the line cord plug and a protruding ground pin on the wall receptacle, and in Germany and Russia (Type F two pin with a ground connection provided by a metallic clip below the hot pin connections and at the edge of the line cord plug and electrical receptacle socket. CF: Wikipedia for a nice detailed article describing these connectors.
  • OLD HOUSE ELECTRICAL WIRING discusses the inspection and repair of old house electrical systems including wiring and other devices
  • FPE - Federal Pacific Stab-Lok electric panels discusses these latent safety hazards in homes and provides a very detailed history of this product
  • First generation electrical wiring, including from Thomas Edison's D.C. electricity era, used a pair of physically separated copper electrical conductors insulated with cloth and stapled to building framing. Where this wiring was to be exposed to moisture its cloth covering was sealed with tar or similar bituminous compounds and buried in a wooden trough according to a Wikipedia entry. It is unlikely that you'll find this wiring in active use, but if you do, it's dangerous and should be replaced.
  • GAS PIPING used to route electrical wires: often in older homes when gas service was discontinued the gas pipes were used to route electrical wires through building walls, particularly when the occupants wanted to install an electric light where a gas light had previously been found. But don't assume all gas piping in an old house has been abandoned - it may still be "live", as we discuss
  • KNOB & TUBE WIRING details this electrical wiring system, and also see other old house electrical wiring and its history that are provided here. Knob and tube wiring is probably the oldest electrical wiring style that was applied with any standard consistency, and was used from 1880 right up into the 1970's in some jurisdictions, though it fell from widespread use by 1940 when less costly insulated electrical cables increased in popularity.
  • Plastic Cable - "Romex" was introduced in the U.S. in 1950 with a PVC insulating jacket according to a Wikipedia entry.
  • Rubber-insulated electrical cables were introduced in 1922 and contained two electrical conductors insulated with a rubber coating and wrapped with an asphalt-like impregnated cloth. Some inspectors refer to this as "cloth" or "fabric" wrapped electrical wiring but it's not, it's rubber-insulated.
  • Wooden floor baseboard trim and other wood molding trims in older homes were often routed on their back side in order to run electrical wires. Be careful in driving nails through wood baseboards before you know if wires are present.
  • Zinsco/Sylvania electrical panels discusses these latent safety hazards in homes

Flooring Materials as Indicators of Building Age

Please see our full-text articles on types and eras of use of various building flooring materials found in the articles listed under:   FLOORING MATERIALS, Age, Types

Abbreviated comments on some flooring types are also found just below. In some cases, floor covering such as carpets and tiles have been in use for thousands of years. If we comment on these materials it is to identify certain modern variations such as ceramic bath or wall tiles that are purchased pre-glued to a mesh backer to speed tile placement. But in general we focus on flooring materials that have special properties, ability to date the era of their use, or environmental concerns.

Various types of flooring and the inspection, diagnosis, and repair of flooring defects are discussed
at FLOOR TYPES & DEFECTS. Types of building flooring that contain asbestos, a health and environmental concern, are discussed in detail

List & History Resilient Floor Coverings Used in buildings

Resilient floor coverings include organic flooring materials such as asphalt tile, cork tile, linoleum, rubber flooring, vinyl tile, vinyl sheet flooring.


Asphalt Tile Flooring as an Indicator of Building Age - 1920 - 1960 (est)

Black tile flooring, maybe not asphalt based

In 1920 asphalt roofing manufacturers, who had been using asphalt and fiber binders to make asphalt roofing shingles for some time, tried to develop a rigid product that could be a substitute for (more costly) slate roofing.

The material did not perform acceptably as a roof covering, but it led to the development of asphalt floor tiles.

Asphalt floor tiles are 9" square (or other sized) tiles which used asphalt as the main binding material. the original asphalt tiles were produced only in dark colors because asphalt was a main ingredient.

Rosato indicates that the first publicized asphalt tile installation was in 1920 in New York City's Western Union office.

The product was very successful and by 1936 over four million square yards of asphalt floor tiles were being sold annually. By 1940, 5% of floor coverings sold in the U.S. were asphalt tile. -- Rosato

If you encounter black or very dark asphalt floor tiles they are probably very high in asbestos fibers. We discuss floor tiles as an asbestos fiber source in buildings in more detail at ASBESTOS FLOOR TILE IDENTIFICATION.

Cork Flooring Tiles as an Indicator of Building Age -

Cork floor tiles were considered a warm, quiet, but less durable resilient floor covering than some of its competitors. It was sold often for use in residential dens, family rooms, or other warm, low-traffic areas, and it may have been popular (research needed) for use in areas where workers had to spend long periods standing - where it would have competed with rubber floor coverings. In 1952 cork flooring sales made up 2% of total floor tile sales. -- Rosato p88.


Vinyl Asbestos Floor Tiles as an Indicator of Building Age - 1930 - 1976 (est)

Asbestos containing vinyl asbestos floor tiles

Vinyl floor tiles, including vinyl-asbestos floor tiles and homogenous vinyl floor tiles (non-asbestos product) are almost as old as asphalt floor tiles. By the early 1950's in the U.S. vinyl tile floor products were more popular than asphalt-based flooring. The reason is pretty obvious.

Asphalt-based flooring as it was originally produced used heavy asphalt products which meant that the floor tiles could be made in dark colors only.

Soon after asphalt-asbestos floor tiles were marketed manufacturers heard from their buyers that consumers wanted lighter floor tiles and tiles of varying color and pattern.

Organic resin vinyl increased in popularity for this reason, but slowly. By 1952, the production of vinyl plastic floor tile sales in the U.S. was about half the volume of asphalt floor tiles, selling 35 million square yards.

Microphotographs of vinyl-asbestos floor tiles can be seen at our article at ASBESTOS FLOOR TILE IDENTIFICATION. -- Rosato

Sheet Flooring Materials That Indicate Age of a Building

PHOTO of interior floor covering, pre-vinyl, probably linocrusta with burlap fabric backing, Justin Morrill House, Vermont, ca 1845 - 1900

Here is a photograph of an early (pre-vinyl) continuous floor covering, ca 1900, in an 1840 historic Vermont house.

Note the fabric backing of the flooring material. This article explains various common flooring materials (rough wood, finished wood, parquet, carpeting, linocrusta, sheet vinyl, and other items as they assist in determining The age of a building or other building.




Linoleum Sheet Flooring As an Indicator of Building Age - 1890 - 1960 (est)

According to Rosato, "The original resilient floor coverings were developed during the latter part of the Nineteenth Century by Frederick Walton. The original covering was linoleum for use as a floor decking on British naval ships." The composition of the original products included asphaltic binders to which an asbestos filler was added by mixing on a rubber mill.


List of Non-Resilient Floor Coverings Used in buildings

Non-resilient floor coverings used in buildings that can assist in determining the age of a structure include bamboo, brick, concrete, stone, and a wide variety of wood products.

See NON-RESILIENT FLOORING as well as the following:

Determining the Age of buildings Using Laminate Flooring Products

Buckled laminate flooring after floodingContemporary snap-together flooring products that resemble wood or other surfaces, but are made of plastic, and other pre-finished and ready-to-assemble wood flooring products are a much more modern product.

Sadly the laminate floor shown at left was ruined by a building flood. Pressure from expanding materials absorbed both the original free space around the floor perimeter and added enough force to buckle the flooring up at the center of the room.

Pergo™ laminate flooring, for example, was developed by Pergo AB, a Swedish company founded around 1890 as a vinegar manufacturer. Product development for Pergo laminate flooring began in 1977 and was first brought to the market in 1984. Pergo laminate flooring was first sold in the U.S. in 1994.


Foundation Materials as Indicators of Building Age

Pre cast concrete foundation © Daniel FriedmanFoundation materials commonly used for buildings include:


  • Wood, beams set on grade or on flat stone set on or close to ground level
  • Stone, natural found on site or brought to the building site
  • Brick, less commonly used below grade, more often used from grade-level up, set on stone below grade.
  • "Cinder blocks" or concrete blocks
  • Poured concrete
  • Pre-fabricated concrete foundation sections assembled onsite (photo at left)
  • Wood, treated lumber, treated plywood on treated wood or on concrete studs

In evaluating the probable age of a home when inspecting its foundation, we consider the foundation materials and style of workmanship.

PHOTO of a buckled stone foundation ca 1860, with evidence of building and
structual modification.A photograph of a buckling, damaged stone foundation on an 1864 structure in Rhinebeck, NY is shown at left.

A building's foundation materials and style of construction, stone, wood, brick, masonry block (at least two different generations), and poured concrete (various generations and methods including hand-built and by machine and pumper truck) can give considerable information about the foundation age.

On occasion we'll find a very old structure which has been moved and re-set on a new concrete or concrete block foundation, adding more historical information to the home.

All of the common building foundation materials, how they fail, how they are inspected, are discussed at The Foundation Crack Bible.

Framing Materials as Indicators of Building Age

  • Logs, various sizes, chopped, dried, assembled at the building site
  • Hand hewn beams, chopped and then sized with an adze and axe. Adze cuts and axe cuts are normally visible in the rough surface of hand hewn wood structural beams.
  • Full-sized 2"x4" (or larger 2 x n") wood framing materials
  • Modern wood framing wall studs 2x4's (3.5" x 1/5") and larger members (x" deep by 1.5" thick)
  • Glulam beams; large timbers are built-up of laminated wood strips
  • Tongue and groove wood subflooring, wall sheathing, roof sheathing
  • Plywood subfloors, wall sheathing, roof sheathing
  • Oriented-strand board subflooring, wall sheathing, roof sheathing - see OSB
PHOTO of post and beam framing with joint number markings.

Here is a photograph of post and beam framing with joint number markings.

The observation of framing materials, framing markings, and framing styles provides considerable information about the probable age of a house.

We discuss framing materials and styles here as an aid to house age determination.

Also see our article on " Saw Cuts and Tool Marks" (links at page left).

Log framing and both modern and antique log construction are discussed at Log Home Guide.

Antique and modern trusses are distinguished and modern laminated beams and I-truss beams and wood joists are discussed.

Framing Methods as Indicators of Building Age

Common wood structure framing methods include the techniques described below, arranged alphabetically, not by age.

For the full text articles on this topic please see


Below we provide abbreviated discussion taken from the full-text articles listed above.

Arkansas framing system: 2x6 wall studs are spaced 24' on center, a spacing that permitted installation of more wall insulation volume than provide by conventional 2x4 wall studs.

The Arkansas building framing method became popular in North America following the 1970's arab oil embargo and addressed concern for high energy costs.

Balloon Framing Construction Method Description

For full details see our full text article
at FRAMING METHODS, Age, Types and Balloon Framing

Tall wall studs run from the sill plate atop the foundation wall to the top plate below the building rafters. Wall studs and first floor joists rest on the building sill plates (flat wood members set atop the building foundation). The wall studs extend from the first floor sill to a height sufficient to frame both the first and second floor walls.

First floor joists and second floor joists are framed by nailing to these tall wall studs at the appropriate heights. Rafters attach to the top plate of the building walls. Ceiling joists for the top floor are nailed to the sides of the balloon-framed wall studs just as the floor joists were nailed below.

Glulam Beam Construction, Description, History

(In process, contributions invited). For full details see our full text article
at FRAMING METHODS, Age, Types and Glulam Beams

Log Home Construction Methods Defined & Described

For full details see our full text article
at FRAMING METHODS, Age, Types and Log Home Construction

(1640 - est U.S.): solid logs usually felled and prepared at or close to the building site, set on ground level, on flat stones on ground, or on a stone foundation, corners joined using various notch and overlap methods. See Log Home Guide.

Modular Construction Methods Defined & Described

Modular home during set process © Daniel FriedmanFor full details see our full text article
at FRAMING METHODS, Age, Types and Modular Construction

Modular construction (1910 - present) was first provided on a large scale with Sears Kit homes that were distributed from about 1910 to 194o0 - see How to Identify Sears Kit Houses.

Some modern modular homes built in the U.S. during the 1950's post war building boom originally enjoyed a less than stellar reputation several decades ago, having the reputation of flimsy construction.

That is no longer the case. Since at least the 1980's a modular home is constructed in a factory of one or more sections which are carried to the building site on a trailer (photo above left) and lifted by a crane to be set upon a foundation which has been prepared ahead of time.

Modular homes can be quite large, involving four or quite a few more individual sections which are lifted and "set" into place at the site (photo at left)

Some manufacturers provide custom architectural services and can deliver unique, but factory-built homes in sections.

Nails, Screws & Similar Hardware as Indicators of Building Age

Details about nails and similar hardware and examples of how they can help determine the age of a building are
at NAILS & HARDWARE, Age, Types

OSB - Oriented Strand Board Used in Building Construction, History, Description, Identification

For full details see our full text article
at FRAMING METHODS, Age, Types and OSB

Panelized Building Construction Defined & Described

For full details see our full text article


Panelized construction: floor and wall panels constructed in a factory are delivered to and assembled at the building site. Panels may be conventionally-framed stud walls in modular sections or structural panels may be constructed of a sandwich of OSB (oriented strand board), plywood, or wafer board on either side of solid foam board insulation.

Panelized construction makes use of wall, floor, ceiling or roof "panels" which have been framed off-site and brought to the site by truck. Panels are lifted into place by crane and fastened together on a foundation, and possibly a framed-in floor which have been prepared before the panels arrive.

Some framing panels make use of special materials, such as plywood and foam roof panels for insulated cathedral ceilings.

(In process, contributions invited).

Plank House or Box Construction Method Defined & Described

For full details see our full text article


1880 - 1920 estimated, with some plank house construction continuing up to possibly 1950. Plank houses were constructed entirely of sawn planks and without the use of larger dimensioned 2x lumber. Some of the plank houses we've inspected were made from scraps or salvaged lumber such as a home in Dutchess County New York that was constructed from packing crate wood. Larger collections of plank houses were built as company housing in the mining or railroad industries.

(In process, contributions invited).

Platform Framing Construction Method Defined & Described

For full details see our full text article


The platform frame construction method, also called western construction is the most-common residential wood structure framing method in North America. A floor is constructed atop of the building foundation, forming the first "platform", using the platform as a working surface.

Plywood Used in Building Construction, History, Description, Identification

For full details see our full text article at FRAMING METHODS, Age, Types



Plywood (1905 - present as a construction material in North America) is sheet material made of thin veneers of wood that are laid with wood grains in alternating direction, glued, heated, and pressed together. Interior plywood is generally glued with urea formaldehyde based glues; exterior plywood and marine plywood use phenolic formaldehyde glues and are water resistant.

The cross-grain construction combined with glue produces a strong, uniform material that is used for both enclosure and for structural stiffness in frame construction of building walls and roofs. The properties of plywood, including its tolerance to weather exposure (marine plywood) depend on the glues and finishes used. Both softwood and hardwoods are used in plywoods, and fine wood veneer finishes are also available (for furniture use).

Also see Oriented-strand board subflooring, wall sheathing, roof sheathing -
at OSB

Post & Beam Construction Method Defined & Described

Post and beam construction, brick infill © Daniel FriedmanFor full details see our full text article


Post and beam construction (1700 - est. in North America): (timber framing) uses horizontal and vertical timbers that are connected (joined) using mortise and tenon joints pinned with wood pegs (treenails).

Timber frame construction initially used hand hewn beams, later manually or mechanically sawn beams cut by a pit saw.; Later timber frame beams were sawn in mills using circular saws.

Timber framing using post and beam construction with mortise and tenon joint connections was used in Europe for at least 500 years before it was first employed in North America.

By 1650 a typical timber frame building used multiple bents and girt beams, may have been more than one story tall, and included an exterior made of horsehair-reinforced cement stuccoed over hand-split lath. Our photo (above) shows an 18th century Norwegian timber frame building using brick infill and stucco to complete the wall enclosure.

Welded Wire Sandwich Framing Panelized Construction

Welded-wire sandwich framing panels: polystyrene or polyurethane foam core insulation is surrounded by a welded-wire space frame.\

For full details see our full text article
at FRAMING METHODS, Age, Types and Welded Wire Sandwich Framing

Wood Framing Spacing & Framing Member Actual Dimensions can indicate building age

For full details see our full text article
at FRAMING SIZE & Spacing, Age, Types

  • non-standard wood framing spacings, typically in post and beam or hewn beam frame construction
  • 14" spaced wooden stud framing - early balloon framing
  • 24" spaced wood stud and wood rafter framing, based on a 24" module - all framing, wall studs, floor joists, roof rafters are spaced 24 inches on center. See Arkansas framing above.
  • 16" spaced wooden wall stud and wooden roof rafter or wood roof joist framing

Heating Equipment as Indicators of Building Age

Indoor heating methods by historic periods or years:

See AGE of HEATERS, BOILERS, FURNACES - describing the determination of age & properties of heating equipment, boilers, furnaces by decoding data tags. Where there are special safety or maintenance concerns for certain systems we cite those as well.

  • Central fireplaces, no chimneys
  • Indoor fireplaces, chimney in building or on exterior building wall
  • Free-standing wood-burning stoves, the Franklin Stove
  • Coal burning free-standing stoves;
  • Kerosene stoves
  • Coal fired octopus furnaces and steam boilers
  • Oil burners: different types of oil burners, coal conversions, low speed, high speed, high efficiency
  • Oil-fired furnaces, hydronic (hot water) boilers, steam boilers
  • Gas-fired furnaces, boilers, steam boilers
  • Electric furnaces and heating boilers
  • Geothermal hot water heating systems (e.g. in Iceland)
  • Heat pumps -
    see AGE of AIR CONDITIONERS & HEAT PUMPS - how to read data tags to decode the age
PHOTO of an Octopus heating furnace, originally coal fired, converted to natural gas fuel.

At left we show a photograph of an "octopus heating furnace", originally coal fired, usually by now (if still in use) converted to natural gas fuel.

These octopus furnaces, also called "gravity heating systems" provided heat by natural convection, hot air rising into the building from the top of the furnace where it was delivered to the building first floor through a wood or iron grate, or perhaps delivered through metal ducts.

The original installation usually supplied heat to a home through a central grate in the first floor of the building from where warm air might rise to upper floors.

Later versions or modified original systems added ducts to individual rooms, sometimes still only on the first floor of the building. These furnaces are the ancestor of modern forced hot air heating systems.

This article series describes the properties, installation, troubleshooting & repair of all types of heating systems and heating system fuel types (coal, oil, gas, wood, solar, electricity) as an aid in determining the age of a home or other building.

Insulation Materials as Indicators of Building Age

Insulation materials used in buildings includes:

  • Nothing - no insulation - solid log walls, solid stone walls, providing thermal mass. Chinking or other methods used to reduce air leakage were the principal energy savings or comfort detail applied; adobe and concrete construction.
  • Air - open cavities in wood framed walls; a small 1" air gap is also found in older structural brick walls; the air gap in brick walls was intended to avoid transmission of moisture from outside the building to its interior.
  • Silage or corncobs used as wall insulation
  • Paper, newspaper, rags used as wall insulation
  • Brick, masonry, as wall cavity fillers to block air leaks and provide thermal mass -
    see BRICK LINED WALLS as building insulation
  • Cotton building insulation batts -
  • Perlite building insulation -
  • Asbestos used as insulation in buildings, generally on heating pipes (corrugated asbestos paper lengths wrapped around pipes, asbestos paste at elbows and on boiler exteriors, asbestos paper on heating duct exteriors); asbestos was not normally used as a fill material for the insulation of building cavities though we have encountered it in rare cases.
  • Rock wool or mineral wool used as building wall or ceiling insulation -
  • Paper or foil air and heat reflective barriers used as ceiling or wall insulation in buildings
  • Fiberglass batts used as building insulation -
  • Chopped, fire-retardant cellulose (newsprint) building insulation -
  • Chopped fiberglass building insulation
  • UFFI urea formaldehyde foam insulation used as building insulation -
  • Foam board building insulation products: styrofoam board insulation & other foam insulating board products, paper faced and foil faced insulating boards -
  • Insulated building panels, a wood "sandwich" of solid foam board and plywood, used primarily on building roofs
  • Icynene® foam building insulation
  • Latex foam building insulation and other foam insulation products

See INSULATION IDENTIFICATION GUIDE for a catalog of building insulation materials and how to identify them.

Mineral wool insulation in an attic

At Insulation Material Identification Guide we discuss various types of insulation materials (none, air gaps, brick and brick-lined walls, cellulose, cotton, corn or corn husks, hay bales (including hay bale or straw construction), straw, newspaper, rock wool insulation or mineral wool, fiberglass insulation of various colors (brands), types (batts, chopped, etc), perlitebuilding insulation, asbestos insulation and fire barriers, UFFI and other more modern foam board and foam spray insulation materials, and the use of radiant barriers) and their common eras of usage as an aid to determining the age and history of a building.

Health and environmental concerns and insulation effectiveness are also addressed such as mold in fiberglass insulation and fiberglass fragments in air from various sources in buildings.

PHOTO of brick wall lining used as insulation and wind-block

See Insulation Material Identification Guide for a catalog of building insulation materials and how to identify them.

Our photo at left shows a pre-1900 brick wall lining used as insulation and as a wind or draft block. Brick nogging can determine the probable age for the home.

Houses built between 1810 and 1900, or perhaps earlier may have brick-lined walls. I have found brick nogging in the walls of a 1790 Poughkeepsie NY home.

Bricks lining the walls of a home is an indicator of when it was built. See Brick Lined Walls for a detailed, illustrated article about the use, detection, and inspection of brick lined walls in older homes were we describe and explain the reasons for and concerns with brick wall lining or "insulation" sometimes called nogging.

Guide to Nails and Hardware as Indicators of Building Age

Hand wrought iron spike pre-1830 © Daniel FriedmanA close observation of the type of fasteners used in a building is one of the most popular means of estimating its age. Hand wrought nails, machine cut nails, modern round "wire" nails and other details offer considerable information about the time of original construction of a building as well as of the time of modifications to the structure.

Other framing material & hardware details can assist in determining building age. An examination of nails and fasteners and other building hardware is a complimentary effort useful in determining the age of a building and its components.

Nails, Screws & Similar Hardware as Indicators of Building Age

Details about nails and similar hardware and examples of how they can help determine the age of a building are at NAILS & HARDWARE, Age, Types

Also see SAW CUTS, TOOL MARKS, AGE for additional building age clues likely to be available when examining building framing materials.

Window Latches, Fasteners, Tracks, Window Weights, and Window Components as Indicators of Building Age

Window latch © Daniel Friedman

The window latch shown in our photo (above left) dates from the 1840 Justin Morrill Smith Historic house in Vermont.

Details & photo examples of window hardware and age determination details are also found at WINDOW HARDWARE AGE

Door Hardware: latches, knobs, hinges, construction details as an indicator of building age

Antique door hardware, Suffolk Resolves House 1774 latch © Daniel Friedman

Above is door hardware from the Suffolk Reserves house dating from 1774. Notice in both the door hardware photos above and those shown below that unlike contemporary passage door locksets, the knob setback distance from the door edge is considerably greater. The left hand photos show the door lock hardware and the right hand photos show the knob and key opening on the opposite side of the door.

Details about door hardware age and photo examples of door knobs, latches, hinges, and other details are at DOOR HARDWARE AGE.

Guide to Plaster & Drywall & Other Interior Wall Coverings as Indicators of Building Age

Please see DRYWALL, PLASTER, BEAVERBOARD we describe and discuss the identification and history of older interior building surface materials such plaster and lath, Beaverboard, and Drywall - materials that were used to form the (usually) non-structural surface of building interior ceilings and walls.

Readers should see Sheathing Homasote & Other Board for a discussion of exterior wall sheathing fiberboard products such as Homasote® and Celotex® insulating roof, wall, and foundation board products.

A quick review and description of these materials is provided just below.

History of Plaster, Plasterboard, Drywall, Wood Lath, Metal Lath

PHOTO of hand split lath and plaster ca 1800

Photograph of hand-split wood lath and plaster wall, from the wall-cavity side. Ca 1800.

There are several generations of plaster and lath, plaster board, and drywall which have been used in buildings.

We name and illustrate these and discuss their periods of use below as an aid in finding out how old a building is and tracing its history. Examples:

  • Mud used as a plaster over split wood lath or woven wood lath
  • Horsehair mixed with plaster or cement for building exterior wall covering
  • Other versions of plaster/lath are described at DRYWALL, PLASTER, BEAVERBOARD

History of the Use of Wood and other Wall Paneling in North America

Wooden wall paneling - tongue and groove pine and other woods

in process

Wall paneling in 4' x 8' sheets

in process

Early colonial paneling is described by Isham.

History of Beaver Board & Upson Board Wall Coverings in North America

Details about Beaver-board and Upson Board, a wood fiber product used as an inexpensive interior wall covering and draft blocker from about 1903 are provided at Plaster & Beaverboard & Drywall.

Our photographs (below) show this product from it's back or wall cavity side. On the exposed side this wood fiberboard product was usually painted and its joints covered with wood lath or other trim. In some applications it was covered with wallpaper. In some homes it was later covered with drywall to provide a more fire-resistant surface.

Beaverboard wall covering © Daniel Friedman Beaverboard wall covering © Daniel Friedman

Beaverboard takes its name from the Beaver N.Y. and the Beaver Board Companies that produced this product until that firm was purchased by Certain Teed Prod cuts in 1928. Beaver Board and Upson Board were produced by the Beaver Wood Fibre Company Limited, in Thorold, Ontario.

Beaver board's competition was from Upson Processed board (John Upson, Upson Company, Lockport, NY) which was produced beginning in 1910. As late as the 1950's Upson Board was used in prefabricated houses and exterior building sheathing and in recreational vehicles. Upson purchased the Beaver Board plant from CertainTeed in 1955. Upson began its decline in the 1970's and closed in 1984, opening later that year as Niagara Fiberboard.

Guide to Plumbing Materials & Fixtures as Indicators of Building Age

PHOTO of gas light fixture which we discovered still was fed by an active gas line in an 1860 New York HomePlease see AGE of PLUMBING MATERIALS & FIXTURES for our detailed article on determining the age and life expectancy of plumbing components.

Photograph of an active gaslight found in a 1900 home in New York.

Often old gas lines have been disconnected entirely and sometimes they have been re-used to route electrical wiring to new light fixtures or to gaslight fixtures which have been converted to electric.

Don't assume that an old gas fixture or valve on a wall or found in a fireplace are inactive.

We turned-on and lit this fixture which gave a bright surprise to everyone.

Watch out for "live gas" connections to supposedly abandoned gas piping and don't trust "... yeah that was disconnected years ago" unless you can see both ends of a section of abandoned gas piping in a building.

Chart of Dates When Different Types of Plumbing Were Used in Homes

Chart showing when different types of piping were used in homes (C) CarsonDunlop

Plumbing fixtures and piping materials offer considerable age in dating a building, including easy clues such as the presence of a date of manufacture stamped into many toilet tanks to the periods of use of types of water supply piping (lead, galvanized steel, black iron pipe, copper, plastic piping) and building drain piping (lead, cast iron, copper, plastic, clay).

Often on older buildings multiple types of piping will be present as repairs and changes have been made in the building plumbing system.

Chart of plumbing types and years of use courtesy of Carson Dunlop

Please see AGE of PLUMBING MATERIALS & FIXTURES for our detailed article on determining the age and life expectancy of plumbing components.


Roofing Materials as Indicators of Building Age

PHOTO of wood shingle roof, Key West Florida, adjacent to Hemingway's house Wood shingle roofing has been in use for hundreds of years in the U.S. and Europe.

But an inspection of interior and exterior roofing details can indicate the probable age of a wood roof (which can last up to 40 years) as well as the roofing history of the building, the number and types of roofing layers, and related house-age-determination details.

The wood shingle roof shown in the photo below is on a building in Key West, Florida, adjacent to the Hemingway house, viewed from the Key West tower.

Notice the absence of lichens on the wood shingles in the roof area below the metal-flashed rooftop tower?

We discuss here various roofing materials (Wood, slate, asphalt shingles (in several generations), clay tile, metal roofing (several styles and generations), and how they assist in finding The age of a building below.

History and Dates of Use of Various Roofing Materials

This article series explains the eras of use of different types of roofing materials as an aid to understanding the history and age of buildings. If you are trying to determine the age and condition of a particular roof covering, please see Roofing.

Cement Board & Fiber Cement Building Products

Asbestos-Cement Board & Fiberboard Products

Exterior Siding & Roofing Using Asbestos Cement included asbestos cement shingles, asbestos cement siding, corrugated asbestos-cement roofing.

See Asbestos Roofing Materials and ASBESTOS CEMENT & FIBER CEMENT SIDING

Other fiber cement materials used in construction included
Transite Pipe Chimneys & Flues
Transite Pipe Water Supply Piping


Modern Cement Board & Fiber Cement Products

Cement board is a non-structural building sheathing material which in its contemporary form is made from Portland cement covered with a reinforced fiberglass mesh fabric. Cement board is used as a tile backer or a backer board for stucco applications on buildings. Current producers include Custom Building Products (WonderBoard™) and US Gypsum (Durock™).

Panels made of a mixture of cement and wood fibers are produced for building siding by James Hardi (Hardi-panel and Cemplank™), and CertainTeed (Weatherboard™).

(History & dates in process, contributions invited - CONTACT us)

Saw Cuts, Tool Marks as Indicators of Building Age

Hand hewn beam © Daniel FriedmanGenerations of types of saws used in cutting beams, and similar details are readily available on many buildings and offer both clues to building age and wonderful aesthetic detail.

Details at SAW CUTS, TOOL MARKS, AGE show clues such as hand hewn adze marks or even the type of saw cut marks on framing lumber, in rough chronological order. There we illustrate different types of saw and tool cut marks in wood: adze cuts, hand sawn pit saw marks, mechanically-operated pit saw marks, circular saw marks, and unmarked, planed modern dimensional lumber.

An excerpt from that article is our photo at left and this explanation: An understanding of how hand-hewn beams were cut, for example, can permit the careful observer to not only recognize the type and age of building framing, but even to understand just where the worker was standing when a blow from a tool was delivered to a building framing member.

Adze cuts to hew a rectangular beam out of a round log were made in two steps: an adze, a hoe-like cutting tool with wooden offset handle was used to make a series of cuts along the round up-facing surface of a log.

Sears Kit Houses as Indicators of Building Age

For details, photographs, books, and references on how to identify Sears Kit Homes see Sears Houses: How to identify Sears catalog kit houses photos and tips for identifying these interesting homes.

PHOTO of stencil numbers on wood framing indicating a Sears Kit HouseFor information about the age, history, and use of pre-cut lumber in wood-frame construction, see Pre-Cut Lumber Construction

A photograph of stencil numbers on wood framing shown here confirms that this building was a Sears Kit House whose model and probable age we can determine.

Other kit homes were sold by Montgomery Ward and by a few other manufacturers including copies of some of the popular Sears and Roebuck houses that continued to be sold after Sears had discontinued their production.

This article explains types of kit homes including kit houses and log home kits which, in the latter instance continue to be improved and sold.

For more details, photographs, books, and references on how to identify Sears Kit Homes see Sears Houses: How to identify Sears catalog kit houses photos and tips for identifying these interesting homes.

Siding Materials as Indicators of Building Age

Please see our detailed article on types of siding and how siding materials are inspected, installed, diagnosed, repaired, at Siding, Sheathing Identification - Photo Guide

PHOTO of asphalt siding on the Coolidge Hotel, White River Junction Vermont

Asphalt siding such as that shown in the photo of an extension on the rear of the Coolidge Hotel in White River Junction, Vermont, was the "aluminum siding" of the 1930's and 1940's in the United States.

That is, it was a popular "no maintenance" siding material sold often as a cover-up product for older siding in poor condition. (Aluminum siding and then vinyl siding were sold both for that purpose and also as exterior wall cladding for new construction as well). See SIDING ASPHALT SHINGLE or SHEET.

Asphalt siding material was made in two common versions, one much like asphalt roof shingles and the other (as in this photo) was comprised of an asphalt coating laminated to hardboard siding material.

Commonly made to look like brick, it also appears in faux-stone versions (not to be mistaken for "perma stone" which has been sold since the 1960's as an exterior wall covering. It would be rare to find asphalt-based exterior siding material as original wall cladding on a building; usually it was applied over wood clapboards which in turn were badly in need of paint or repair.

History and Dates of Use of Various Building Exterior Siding Materials

Details of how this material deteriorates and examples of its variations are discussed below along with other exterior siding materials and their common dates of use.

PHOTO of an 1840 window latch on a historic Vermont HomeWindows & Doors & Interior Hardware as Indicators of Building Age

Please see our windows and doors articles at WINDOWS & DOORS, Age, Types and also see WINDOW HARDWARE AGE

At left is a photograph of an 1840 window latch on a historic landmark property, the Justin Smith Morrill Homestead in Strafford, Vermont.

This articles cited above explain how we can use details about the construction and materials of use in windows and doors as clues to building age, including window style, size, placement, construction, and hardware, as well as door style and hardware.

For example, in addition to antique window hardware, take a look at the window glass type, window dimensions (and regularity of dimensions of similar windows in the same building), and the construction of window sashes with or without through-cut muntins. Notice too how the window is held in an open position: by a removable peg, by sash weights, by window springs, or in the case of renovated antique windows where sash weights were eliminated, the presence of compression tracks that hold window sashes in place.

How Old is My House? Reader Photo Submissions

I am attempting to verify the age of my new home. I was told it is circa 1830.

Here are some photos of construction and hardware (attached). L.H. 7/9/2014

Determine age of this ca 1830 home (C) InspectApedia LH Determine age of this ca 1830 home (C) InspectApedia LH Determine age of this ca 1830 home (C) InspectApedia LH


The photos you show of a door hinge and interior door lock hardware are consistent with a home of that age or perhaps a bit more recent - depending on where it is located. This is a very simple door hinge that I have seen on homes of the age you speculate.

Determine age of this ca 1830 home (C) InspectApedia LHDetermine age of this ca 1830 home (C) InspectApedia LH

The sawn-lath strips and what look like wideboard pine flooring that place the home certainly well before 1900. Had the lath strips been split but not sawn I'd have figured the home was older still.

Determine age of this ca 1830 home (C) InspectApedia LH Determine age of this ca 1830 home (C) InspectApedia LH

The exterior window hinge looks like a casement window that is probably considerably newer than the home as does the bathroom wall tile.

Determine age of this ca 1830 home (C) InspectApedia LH

The bath sink is younger than 1830 and in fact it's likely that when the home was built it did not have indoor plumbing.

Determine age of this ca 1830 home (C) InspectApedia LH

It's tough to pin down the age of a home precisely with just photos and without location and other details, since those materials you show were used over many years and as their inception varies by where geographically the building is located.

In addition to having a general idea of the age of the home, I'd look for inscribed dates on building materials and for documentation both in the home itself and in local records such as tax files and building or town deeds.


Continue reading at FOUNDATION MATERIAL AGE or select a topic from the More Reading links shown below.

Or see ARCHITECTURE & BUILDING COMPONENT ID where we aid in identification of building architecture, components, and styles, many of which also can help date the era of construction of a building.

Suggested citation for this web page

AGE of a BUILDING - how to determine at - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

More Reading

Green link shows where you are in this article series.


Frequently Asked Questions (FAQs)

Click to Show or Hide FAQs

Ask a Question or Search InspectApedia

Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.

Search the InspectApedia website

HTML Comment Box is loading comments...

Technical Reviewers & References

Publisher's Google+ Page by Daniel Friedman

Click to Show or Hide Citations & References