Most American homes in the 1970s were heated by natural gas, which had surpassed all other fuels to reach over 50 percent of households by 1970. Fuel oil was the second most common source, heating roughly one in four homes, while electric heating and a handful of older fuel types filled in the rest. The decade brought dramatic upheaval to all of these systems, as two energy crises forced families to rethink how they kept warm.
Natural Gas Was the Dominant Fuel
Natural gas had grown explosively in the postwar decades, jumping from just 11 percent of homes in 1940 to over 50 percent by 1970. In some states, particularly in the West, it was nearly universal. California alone had 67 percent gas heating as far back as 1940. Most gas-heated homes used a forced-air furnace in the basement or a utility closet, pushing warm air through sheet-metal ductwork to registers in each room. Others relied on floor furnaces, wall furnaces, or gravity systems that let warm air rise naturally without a blower.
Gas was cheap, widely available through expanding pipeline networks, and cleaner than the coal furnaces it replaced. By the mid-1970s, though, supply tightened. A combination of price controls and surging demand created regional shortages, particularly in the eastern United States during the brutally cold winter of 1976-77. Congress passed the Emergency Natural Gas Act of 1977 to allow interstate transfers of gas supplies to the hardest-hit areas. For homeowners, the message was clear: even the country’s most popular fuel wasn’t immune to disruption.
Fuel Oil and the Price Shock
Fuel oil, including kerosene and other liquid fuels, had peaked around 32 percent of American homes in 1960 and was already declining when the 1970s began. It remained especially common in the Northeast, where older row houses and colonials had oil-fired boilers in their basements feeding hot water or steam to cast-iron radiators. Other setups used oil-fired warm-air furnaces similar to gas models.
The 1973 Arab oil embargo changed everything for these households. The price of crude oil nearly quadrupled, jumping from $2.90 a barrel before the embargo to $11.65 by January 1974. Home heating oil prices followed, and families that had budgeted a few hundred dollars for a winter’s worth of fuel suddenly faced bills several times larger. Gas stations posted signs limiting purchases to 10 gallons per customer, and the ripple effects reached every oil-dependent home. A second oil shock in 1979, triggered by the Iranian Revolution, drove prices even higher. Together, these crises accelerated oil heating’s decline for the rest of the century, dropping to just 9 percent of homes by 2000.
Electric Heating’s Rapid Rise
Electric heating was barely a factor in 1960, used by only 1.8 percent of American homes. Over the next two decades it climbed rapidly, and by the end of the 1970s it had established a significant foothold that would eventually reach 30 percent of homes by 2000.
The most common form was electric baseboard heating: long, low metal units mounted along exterior walls, each with its own thermostat. They were cheap to install, required no ductwork or chimney, and appealed to builders looking to keep construction costs down. Electric utilities actively promoted them, sometimes offering rate structures where electricity got cheaper the more you used. For a builder putting up a subdivision, skipping the furnace, ductwork, and chimney meant real savings on every house.
The tradeoff was operating cost. Electric resistance heating converts electricity to warmth at a one-to-one ratio, which sounds efficient until you consider that the power plant burning fuel to generate that electricity loses most of the energy before it reaches your home. In mild climates this was tolerable, but in cold northern states, winter electric bills could be staggering. Heat pumps offered a more efficient alternative, pulling warmth from outdoor air rather than generating it directly. They existed in the 1970s but were less reliable and less efficient than modern versions, and they struggled in temperatures below freezing, limiting their appeal to southern and mid-Atlantic states.
Coal, Wood, and Holdover Fuels
Coal had been the country’s dominant home heating fuel as recently as 1940, when 55 percent of households relied on it. By 1970, that figure had plummeted to 2.9 percent and continued falling. The coal furnaces that remained were mostly in older homes in Appalachia and parts of the industrial Midwest, where coal was locally mined and cheap. These systems required manual stoking, ash removal, and a tolerance for dust that most postwar homeowners weren’t willing to accept.
Wood heating, which the Census Bureau tracked separately, saw a modest revival in the late 1970s. As oil and gas prices spiked, families in rural areas rediscovered the wood stove. The airtight cast-iron stoves that became popular in this era were a significant improvement over open fireplaces, which lose most of their heat up the chimney. For households with access to cheap or free firewood, a wood stove could slash heating bills dramatically, even if it meant splitting logs and cleaning creosote from the flue.
How Thermostats Worked
The device controlling all of this was far simpler than today’s smart thermostats. The standard 1970s thermostat was an analog unit mounted on an interior wall, typically made by Honeywell. Inside, a bimetallic strip (two metals bonded together that bend at different rates as temperature changes) tilted a small glass tube containing mercury. When the temperature dropped, the strip bent enough to tip the mercury to one end of the tube, completing an electrical circuit and switching on the furnace. When the room warmed up, the strip bent the other way, the mercury slid back, and the furnace shut off.
More advanced models like the Honeywell Chronotherm added a clock face with colored pins. You could insert red and blue pins at different hours to set daytime and nighttime temperatures using two levers on the front. It was an early programmable thermostat, entirely mechanical. The system wasn’t precise by modern standards, with temperature swings of several degrees around the set point being normal, but it was reliable and required no batteries or software updates.
The Solar Experiment
The energy crises also sparked serious interest in solar heating. Architects and engineers experimented with both active and passive solar designs throughout the decade, particularly in the sunny Southwest. Active systems used flat plate collectors mounted on rooftops to absorb sunlight and transfer the heat to water or air circulated through the home. Near Corrales, New Mexico, builders constructed experimental homes with glass walls that opened during the day to let sunlight heat blackened 55-gallon drums filled with water. At night, the walls were covered, and the drums slowly released their stored warmth.
These projects were genuinely innovative, and some worked well. But solar heating remained a niche pursuit. The collectors were expensive, the systems were complex, and when oil prices temporarily stabilized in the early 1980s, much of the urgency faded. The technology laid groundwork for later developments, but in practical terms, solar heated only a tiny fraction of 1970s homes.
Regional Differences Shaped the Experience
Where you lived in the 1970s largely determined how your home was heated. A family in suburban Boston likely had an oil-fired boiler feeding hot water radiators, and they felt the 1973 embargo acutely. A family in Houston probably had a gas furnace with central air conditioning already built into the same duct system. A new home in the Carolina Piedmont might have had electric baseboard heat, installed cheaply by a developer banking on low electricity rates. A farmhouse in Vermont might have supplemented its aging oil furnace with a cast-iron wood stove after the second price shock in 1979.
These regional patterns persisted for decades. The Northeast’s reliance on heating oil, the South’s embrace of electric heat and early heat pumps, and the Midwest’s deep connection to natural gas all trace back to infrastructure and pricing decisions made in the 1960s and 1970s. The energy crises of that decade didn’t just raise prices temporarily. They permanently reshaped which fuels Americans trusted to keep their homes warm.