After a sharp slump at the end of last year, the government announced the other day that housing construction has been edging up for three months in a row.

As welcome as this development is, don't start cheering yet. The new construction consists of apartments. Construction of single-family homes is declining, and rising mortgage interest rates can be expected to further that trend.That means the American dream of owning a home is fast becoming an impossible dream for many young couples, particularly those with average or less incomes.

America's home ownership rate has dropped from the peak rate of 65.6 percent in 1980 to 63.8 percent today, meaning nearly 2 million fewer families can own their own homes than if the previous rate had been sustained.

While the plight of the families who can't afford a home of their own has recently come to the fore, the problem has been a long time in the making. Most experts peg the beginning at 1974 when, for the first time, housing costs started increasing in double-digit numbers and kept it up for nearly a decade. At the same time, wages -spurred by inflation - also rose dramatically but failed to keep pace with home prices.

Today, an income of $50,000 is just barely enough to qualify for a home in the nation's large metropolitan areas, although in Utah, with lower-than-average home prices, that's considered an adequate income for homes wanted by most families.

But Utahns, particularly younger ones with new families and lower-than-average incomes, are finding it as hard to qualify for home mortgages as other Americans.

Part of the problem is the Reagan administration's slashing of government support for low-income housing programs from $25 billion in 1981 to $7 billion this year.

Middle-income people have felt the cutbacks also. Until a few months ago, the Federal Housing Administration - a key source of low-cost financing - stubbornly refused to raise the limits on the size of loans it would insure. Another important federal government insurer of mortgage loans, the Veterans Administration, also kept its loan limit low.

The government-chartered Federal National Mortgage Association has also tightened its loan standards, making it harder for borrowers to buy a house with only 5 percent or 10 percent down.

But it's unfair and inaccurate to place the blame exclusively on the policies of the Reagan administration, policies prompted at least in part by the need to curb government spending so as to eventually eliminate the massive federal deficxit.

Potential homebuyers also must accept much of the responsibility for their plight as they have opted to buy all sorts of goods and services now, rather than save money for a downpayment on a home. Although some baby boomers have been saving for their first home, many others have splurged on luxury items. In all, the savings rate for Americans has dropped from more than 9 percent of disposable income in 1975 to about 5 percent today.

That's a shame because a home is still a smart investment. Unlike renters, homeowners know they can stay indefinitely where they are and do not have to worry about rent increases. In many places, the value of a home has risen far faster than inflation.

Americans can't abandon the dream of owning their own homes without also abandoning a major source of social stability and economic progress.