Hong Kong’s South Island Line has only four stations, and two of the residential districts it serves are, in transaction terms, barely districts at all. Each is effectively one estate. Over the trailing three years, every registered sale transaction in Wong Chuk Hang belonged to a single development, and every registered sale transaction in the South Horizons catchment on Ap Lei Chau belonged to a single estate. The two sit one stop apart. Per square foot, one costs roughly twice the other.
That makes the pair unusually instructive. Most district comparisons in Hong Kong are muddied by mixed stock — a 1970s walk-up beside a 2015 tower beside a converted tenement. Here almost all of that noise is stripped out: one district is uniformly new, the other uniformly middle-aged, and each has a single deed of mutual covenant and a single management régime. What remains is a comparatively clean reading of what building age, unit mix and construction phase actually cost. The figures below were read from publicly available registered transaction records covering late July and the first three weeks of August 2026. They are individual transactions, not market averages, and any single deal can reflect unit-specific factors that no aggregate captures.
Two districts, two estates, no comparables
Wong Chuk Hang recorded 2,999 registered sale transactions over the trailing three years. Every one sat in the same development, the residential project above and around Wong Chuk Hang station, and 100 per cent of that stock fell in the “under five years old” band. Alongside those sales the district recorded 790 rental transactions over the same period. The South Horizons catchment on Ap Lei Chau recorded 669 registered sale transactions across the same three years, all in South Horizons, with 100 per cent of stock in the 25-to-40-year band.
The practical consequence is identical in both places and easy to overlook: there are no cross-estate comparables. In Mid-Levels or Sha Tin, a buyer can triangulate between three or four estates of similar vintage before making an offer. In these two districts the only comparables are other units in the same development, and the nearest genuinely different benchmark is one MTR stop away. A buyer who does not look across the line is, in practice, negotiating against the vendor’s own reference points.
The price gap, read one deal at a time
In Wong Chuk Hang, a two-bedroom flat of 499 sq ft saleable on the 17th floor of a Phase 4B tower was recorded on 17 August 2026 at HK$14.191 million, or HK$28,439 per square foot. A three-bedroom flat of 773 sq ft in Phase 3B (Blue Coast) was recorded on 10 August at HK$20.26 million, or HK$26,210 per square foot. A one-bedroom flat of 304 sq ft in Phase 6A (Deep Water South) was recorded on 10 August at HK$10.214 million, or HK$33,599 per square foot.
In South Horizons over the same weeks, a three-bedroom flat of 637 sq ft in Block 7 was recorded on 14 August at HK$10 million, or HK$15,699 per square foot; a three-bedroom flat of 614 sq ft in Block 13A on 13 August at HK$8.98 million, or HK$14,625 per square foot; and a two-bedroom flat of 516 sq ft in Block 26 on 19 August at HK$7.48 million, or HK$14,496 per square foot.
The gap is close to a factor of two per square foot, and it is being paid for one MTR stop and roughly three decades of building age. That should be the starting point of any budget conversation about the South Island Line, not an afterthought.
Same budget, very different flat
Per-square-foot figures are abstract. Unit mix is where the gap becomes concrete, and the two districts are close to mirror images.
In Wong Chuk Hang, two-bedroom units made up 47.6 per cent of sale transactions over the trailing three years, one-bedroom units 4.2 per cent and open-plan units 2.13 per cent. By size, 7.32 per cent of deals were in flats of 400 sq ft or less, 68.21 per cent in the 400-to-800 sq ft band and 16.37 per cent in the 800-to-1,200 sq ft band.
In South Horizons, three-bedroom units made up 64.79 per cent of sale transactions and two-bedroom units the remaining 35.21 per cent. By size, 88.21 per cent of deals fell in the 400-to-800 sq ft band and 11.79 per cent in the 800-to-1,200 sq ft band. There were effectively no transactions under 400 sq ft, because the estate does not contain that product.
Put a budget of about HK$10 million against those profiles and the difference stops being academic. In South Horizons, HK$10 million bought a 637 sq ft three-bedroom flat on the 25th floor of Block 7 on 14 August, and HK$10 million bought a 618 sq ft three-bedroom flat on the 30th floor of Block 18 on the same date. In Wong Chuk Hang, HK$9.12 million bought a 300 sq ft one-bedroom flat in Phase 6A on 7 August. Roughly the same cheque, roughly double the floor area and two extra bedrooms — in exchange for a building three decades older. Neither answer is wrong; they are simply not the same purchase.
Inside one tower: what a floor is worth
Because Wong Chuk Hang is a single development sold in phases, it offers something rare in Hong Kong — a near-controlled reading of floor premium. Three flats in the same 499 sq ft two-bedroom stack of the same Phase 4B tower were recorded within a fortnight: the 6th floor at HK$13.745 million (HK$27,545 per square foot) on 7 August, the 12th floor at HK$14.077 million (HK$28,210 per square foot) also on 7 August, and the 17th floor at HK$14.191 million (HK$28,439 per square foot) on 17 August.
The spread from the 6th to the 17th floor is HK$446,000 in price and HK$894 in per-square-foot terms — and note that most of it, HK$332,000, was earned over the first six floors, with only HK$114,000 added over the next five. Floor premiums in tall towers are rarely linear. If a price list or a vendor asks materially more than this for a handful of floors in the same stack, the premium is being justified by something other than height.
Phase beats floor, and it beats size
The floor premium above is worth a few hundred thousand dollars. The phase premium is worth several million.
Within the same Wong Chuk Hang development across the same three weeks, registered per-square-foot prices ranged from HK$26,210 to HK$39,715. At the top, a 960 sq ft three-bedroom flat on the 21st floor of a Phase 4B tower was recorded on 7 August at HK$38.126 million, or HK$39,715 per square foot. In between, a 1,267 sq ft four-bedroom flat on the 29th floor of Phase 3B was recorded on 17 August at HK$40.2906 million, or HK$31,800 per square foot, and a 577 sq ft two-bedroom flat in Phase 6A on 6 August at HK$18.738 million, or HK$32,475 per square foot.
Two things follow. First, there is no such thing as “the Wong Chuk Hang price”: a spread from roughly HK$26,000 to nearly HK$40,000 per square foot inside one development makes any quoted district average close to useless for negotiation. Second, the familiar Hong Kong assumption that smaller flats carry a higher per-square-foot price does not hold cleanly here. The 304 sq ft one-bedroom in Phase 6A transacted at HK$33,599 per square foot and the 499 sq ft two-bedroom in Phase 4B at around HK$28,000 — yet the 960 sq ft three-bedroom in that same Phase 4B tower transacted at nearly HK$40,000. Phase, tower position and product type are doing more work than size. When comparing two units here, the first question is not the floor; it is which phase, and whether they are genuinely the same product.
The older district has a resale record. Read it carefully.
This is where South Horizons offers what Wong Chuk Hang cannot: a long chain of previous sales against which current prices can be measured. It is also where the numbers are most easily misread.
Four South Horizons deals in August 2026 carried a comparison against the seller’s own purchase price. A 618 sq ft three-bedroom on the 30th floor of Block 18 was recorded on 14 August at HK$10 million, up 43 per cent. An 886 sq ft three-bedroom on the 19th floor of Block 21 was recorded on 13 August at HK$14.5 million, up 96 per cent. A 633 sq ft three-bedroom on the 12th floor of Block 20 was recorded on 11 August at HK$9.35 million, up 202 per cent. And a 592 sq ft two-bedroom on the 16th floor of Block 21 was recorded on 17 August at HK$9.2 million, down 5 per cent.
A 202 per cent gain is not an investment return and should not be read as one. It tells you when the seller bought, not what the flat is worth. Held over two decades or more, a gain of that order implies a modest compound rate before stamp duty, fees, interest, management charges, rates and refurbishment: any percentage change against a previous sale is arithmetically dominated by the holding period.
The more revealing detail is that two of those deals were in the same block: one sold up 96 per cent and another down 5 per cent, four days apart. Nothing about the building changed in four days. The variable was the seller’s purchase date. For a buyer, the vendor’s gain or loss is not a fact about the flat.
Wong Chuk Hang has almost no such record. Most of its registered sale transactions carry no previous-sale comparison because there has not yet been one. Where a comparison existed it was sparse — a Phase 3B two-bedroom recorded on 12 August at HK$12 million showed a 27 per cent rise, and another on 5 August at HK$15.85 million showed 16 per cent. Across the small subset of the district’s transactions that could be compared to a previous sale at all, only about 6.7 per cent recorded a fall of within 10 per cent. That sounds reassuring, but a three-year sample from a development still releasing new phases is not a price history; it is a snapshot of one part of one cycle.
What differs once you own it
Building age is not only a price input. With every unit in the Wong Chuk Hang development under five years old, major plant — lifts, pumps, tanks, external finishes — is early in its life and a large capital works levy is unlikely in the near term. The trade-off is that management fees in newer developments start high, reflecting extensive clubhouse and landscaped provision, with little historical record of how they escalate.
South Horizons, uniformly 25 to 40 years old, sits at the other end. Stock of that age is comfortably within normal mortgage tenor, but it will periodically require significant common-area expenditure, so read the owners’ corporation minutes and any special levy history rather than assume the quoted monthly fee is the whole picture. Flats of that vintage also vary enormously in internal condition — a large part of why similar three-bedroom units transacted between roughly HK$14,300 and HK$16,400 per square foot in the same three weeks.
For landlords the calculus differs again. The newer district’s 790 rental transactions over three years, against 2,999 sales, point to a substantial investor-held component, which means a letting there competes against a large and fairly homogeneous supply. In an older, mostly owner-occupied estate, letting stock is thinner but far less standardised, and presentation carries proportionally more weight.
The takeaway
Wong Chuk Hang and the South Horizons side of Ap Lei Chau are one MTR stop apart and, in registered transactions this August, roughly a factor of two apart on price per square foot. The newer district delivers small, uniform, warranty-fresh flats with no resale history and a wide internal price spread driven by phase. The older district delivers family-sized flats at roughly half the per-square-foot price, with a deep but easily misread transaction record and far more variation in condition.
Three habits follow. Price across the line rather than within the estate, because comparables only the vendor can also see are not comparables. Identify the phase and the stack before comparing anything, then let floor height explain the remainder. And treat any percentage change against a previous sale as information about the seller’s holding period, useful for judging how much room a vendor has and useless as a forecast. In single-estate districts the discipline that matters is not finding the best flat in the estate — it is refusing to price the estate without looking outside it.
Transaction figures cited here were read from publicly available registered transaction records for the periods stated. They are individual transactions, not market averages, and percentage changes against previous sales reflect the seller’s holding period rather than any expected return. Nothing here is a recommendation to buy, sell or let a particular property.