Even in Oahu’s high-demand housing market, there’s truth in the saying: “You can lead a horse to water, but you can’t make it drink.” Not when the watering hole consists of tiny, under-300-foot condos that, for their price tag, don’t include amenities and come with resell restrictions that stymie wealth-building potential.

The Sky Ala Moana tower now being built on Kapiolani Boulevard, a block from Ala Moana Center, is offering key lessons for future “affordable housing” projects — and some hard truths.

In an Aug. 6 article, Star-Advertiser reporter Andrew Gomes checked in on sales at the 774-unit Sky Ala Moana twin-tower condo-hotel project, and found this startling situation: Despite Oahu demand for affordable housing, only 14 of Sky’s 84 units under a city affordable-housing program — priced under $515,000 — have sold over the past nine months. Dismal, considering that all of Sky’s market-priced condos in its West tower have sold out, at prices from $568,800 to $1.3 million. The affordable units, called The Flats, all sit in the East tower, below 300 hotel rooms.

Several factors inform why the units aren’t moving: no access to the pool and other building amenities due to lower monthly maintenance fees, and an option to buy a parking space for $38,000. But two other aspects seem particularly unattractive to prospective buyers of The Flats’ who meet applicable median-income requirements:

>> The 84 “affordable” units are priced from $270,000 to $515,000 — and while there are one- and two-bedroom units, most are studios of only 290 or 299 square feet. No debate: That’s very tight for that kind of money.

>> Strict limits on how much buyers can resell their unit for if they sell within 10 to 30 years. Resale of a Flats unit is capped at 1% per year above the original price, plus the cost of improvements made — well below profit margins that a market-unit owner would get for resale.

The Flats is the first condo project here to test this resale-cap at a longer 30-year affordability term, instead of the more-standard 10-year period. But that was an agreed-to condition with the city so that the developer could build fewer units at the lower pricing.

Of course, Sky execs and development interests are now lamenting The Flats’ stagnated sales as a failed experiment. The CEO of JL Capital, the condotel’s developer, said he doesn’t expect the 70 remaining units to sell unless the city allows changes to terms governing Sky Ala Moana’s affordable condos.

But the city should not acquiesce — and certainly not without deeper review of other options. Some rightly suggest, for instance, reducing prices, due to unit size and other limitations.

Holding fast to agreed-upon conditions — secured by developers in exchange for zoning variances and breaks on fees and taxes — will be crucial as new housing projects are proposed. And especially over this next year, when the governor’s yearlong emergency proclamation for housing aims to launch more affordable housing.

The myriad formulas on how many units to offer at what percentages of median income will be all-important, as developers will surely be pressing for zoning and fee exemptions, in order to make their projects “pencil out” financially. Certain to be pushed to the max will be height and density variances in transit-oriented development zones within a half-mile of rail stations.

On this Sky tower and others, government officials will need to stand firm against being too easily swayed by development interests. To remember the great need for truly affordable housing for Hawaii’s current and future workforce of tourism and service workers, of teachers and health-care staffers.

So yes, while it may make sense to ease the 30-year affordability term on some future projects to gain more units, it also makes sense for developers to price their tiny new units more appropriately. Homebuyers know a good deal when they see one, and it shouldn’t be available only to market-priced condo owners. Buyers of “affordable” units deserve decent opportunities, too, and that could happen at The Flats with better prices.