The Housing Board's push to ramp up its supply of flats saw it spend $1.5 billion on housing programmes in the last financial year.
Some 72,737 flats were under construction last year, up from 58,731 the previous year.
As the building programme accelerated, HDB forked out $5.2 billion to buy land, a quarter more than what it paid in the previous year.
The overall effect of this stepped-up building programme was a wider overall deficit for HDB, some $350 million more than the previous year.
"Our key focus has always been to... make home ownership and housing accessible to all segments of Singapore's population," said HDB chairman James Koh Cher Siang in its annual report.
During the year ended March 31, HDB posted a home ownership deficit of $719 million, up from $411 million previously.
Housing grants and the sale of flats accounted for most of the $1.5 billion housing bill, followed by upgrading, rental flats and mortgage financing.
Analysts point to the large number of flats in the pipeline as the main reason for the wider housing deficit.
HDB posted an overall deficit of $797 million before government grant and taxation, up from $443 million the year before.
R'ST Research director Ong Kah Seng said the number of new flats sold has increased substantially since 2011, and many of these are still being built.
Fewer new flats were completed last year, with the number falling to 11,541 units from 17,947 units in the year before.
Since 2011, HDB has launched a record 25,000 to 27,000 new flats per year. This added to the net deficit because HDB will receive non-deposit payments from the buyers of these flats only after they are completed, said Mr Ong.
Furthermore, HDB flats are "priced in accordance with affordability, not construction costs or resale flat pricing. So the risks from rising construction material and labour costs and construction contingencies are borne by HDB", he added.
HDB chief executive Cheong Koon Hean said the agency's "challenge ahead is to ensure smooth completion and delivery of the new flats, given the large volume and resources involved".
To finance its activities, HDB has received a $1.04 billion government grant and issued more bonds worth a total of $6 billion last year.
Mr Koh also said that the housing agency will keep evolving to be more inclusive. "The next chapter of our public housing story must speak of greater diversity."
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