They Don't Build Them Like They Used To
That's a good thing... for the most part. Residential buildings in North America have come a long way since the rough-sawn shacks of the frontier towns. Things like concrete foundations, plumbing, and insulation are all relatively recent innovations. As our standards for comfort have evolved, so too have our building materials and techniques. If you're thinking of buying an older home here are some of the things to expect.
Maintenance is Critical
Any building, no matter what age, is only as good as its owners. As an inspector, there are some special days where you enter a house and could swear you just stepped back in time to the 1970's. Original appliances and equipment, finishes, windows, and furnishings, all lovingly maintained and cared for over the decades. Sometimes there are newer houses, where the owners have done nothing, and let it slip into disrepair. The point is: maintenance can be more important than age.
Nothing Lasts Forever
Every part of a home wears out eventually. From the floor to the roof, every system has an "expected lifespan". In older homes, it is much more common to have a number of these systems all at, or near, the end of their expected life. It can be totally normal for a 40-year old house to need a new roof, furnace, A/C, and water heater all at once.
Settlement and Sag
Settlement is what happens after a building is constructed. Most settlement occurs in the first year or so, when soil is compressed under the weight of the new building. Sag is what happens over time with snow load and gravity. Floors and roofs in older buildings were not built as strong as they are today, and they tended to sag or "deflect" over the years.
Performance
Houses today are built to a relatively high standard of performance compared to the last 100 years. While methods have changed and materials have evolved to make building faster and cheaper, insulation and airtightness are the two biggest things that have shifted in the way we approach modern design and construction.
Eras of Construction
Pre 1930's
A largely unregulated era. Construction methods range from solid masonry to rough-sawn lumber. There is no national building code yet, and building materials are not fully standardized. Stone or brick and mortar foundations are still common. Insulation (when it is used) is often wood chips, newspaper, or rags. Galvanized steel, copper, or cast iron piping, along with knob and tube wiring are standard. Wood shingles, metal, or tar paper are the most common types of roof.
1930's -1940's
A period of rapid change, building materials become much more standardized. The first national building code is introduced in 1941. Masonry block or poured concrete replace stone and brick foundations. Wooden wall framing with shiplap sheathing becomes the norm. Fiberglass insulation, asphalt shingles, and plywood all enter the market during this time, and fused copper wiring becomes the new standard for electrical systems. Oil furnaces replace coal or wood burning units.
1950's - 1960's
The postwar baby boom has North Americans building single family suburban homes at an accelerated rate. Double glazed insulated glass enters the market, enabling designs with brighter interiors and many more windows. Drywall begins to replace lath and plaster on the interior, and trussed roof framing begins to replace rafters. Air conditioning and vinyl siding are invented. The first circuit breakers come onto the scene. Construction starts on Canada's natural gas infrastructure bringing a new source of energy to many homes.
1970's - 1980's
The oil crisis in the '70s has the public thinking about energy consumption. Electric baseboard heat catches on, and air conditioning becomes widespread. Construction of the natural gas distribution network is expanded. Pre-made engineered roof trusses become the standard enabling open floor plans. Copper prices spike, so aluminum is briefly used as a cheaper alternative for wiring. New injection molded plastics like ABS, Poly-B and PVC replace copper, steel, and cast-iron piping. Mid-efficiency furnaces replaced older gravity furnaces, and insulation levels in attics and walls are increased.
1990's - 2000's
A time of major transition towards safety and energy efficiency. Asbestos and lead paint disappear from the Canadian market. Poly-B piping is banned, and is replaced by PEX piping. The first generation of high-efficiency furnaces becomes available. New standards for building homes are introduced that measure the efficiency of energy use, indoor air quality, and the environmental impact of a house.
2010's - 2020's
As energy costs continue to rise, more and more focus is put on improving efficiency and performance. Homes become increasingly insulated and airtight due to updated building codes, and triple glazed windows become widely available. Heat Recovery Ventilators become standard in new construction to manage humidity and indoor air quality. Heat pumps gain traction as a viable heating source in cold climates due to design improvements, and the federal and provincial governments offer large rebates to homeowners for upgrading the energy efficiency of their homes.
How Does it Affect Me?
Historical context is critical for understanding the condition of a house. Sloped floors, foundation cracks, and almost no insulation? All very typical for a 1920's house, but not normal for a 2010's house. Simply put, new houses are built better than old ones. Understanding what is normal for the era allows you to appreciate if the issues identified are typical for that age of house or not.
Key Points
Modern houses are built better than old ones.
Some settlement and sag are normal.
Maintenance is critical to keeping a house in good shape.
Understand what is "typical" for the age of home you are viewing.
Systems in a house wear out over time.