BC 93/99 THE HONG KONG HOUSING AUTHORITY Memorandum for the Building Committee Current Density Guidelines for Public Housing Development PURPOSE The purpose of this paper is to brief Members on the current density controls for public housing development under Housing Authority (HA). BACKGROUND 2. The development of both private and public housing in Hong Kong is controlled by statutory and administrative measures. The main vehicles of control are - (a) Outline Zoning Plans (OZP) ) Statutory (b) Building (Planning) Regulations (B(P)R) ) (c) Hong Kong Planning Standard and ) Guidelines (HKPSG) ) Administrative (d) Metroplan Broad Density Guidelines (BDG) ) 3. The first set of administrative measures which applied specifically to public housing estates were introduced in 1973, when the new HA was established. Gross population density was adopted as the key factor, and the guidelines specified 2,500 to 3,000 persons per hectare, with 2,700 being taken as the average for long term planning and land reservation purposes. However, with the introduction of new block designs (such as Trident 1 and Trident 2), it became apparent that the these density guidelines could not be followed on a regular basis in practice as the achievable densities depend very much on the efficiency of blocks that could be accommodated on site. 4. In recognition of the need to review the density guidelines, a consultancy study was commissioned by the Department in 1990 with a view
- 2 - to establish an appropriate yardstick for the optimum development of public housing sites. As a result, a new concept known as Development Ratio (DR) was introduced, and endorsed by the then Land Development Policy Committee and incorporated in the HKPSG in May 1991. APPLICATION OF THE DENSITY GUIDELINES Development Ratio 5. DR is defined as the Gross Floor Space (including domestic and commercial) of an estate divided by its Net Estate Area (excluding peripheral slopes, free-standing GIC facilities and roads). It is a concept similar to Plot Ratio (PR), both of which relate the floor area of the buildings to their site area. They are, however, based on different definitions of floor area and site area. A comparison of the two approaches is attached at Annex. 6. DR applies to both public rental and HOS estates. PSPS on the other hand is treated as private developments and would be controlled by PR instead of DR. DR is used in public housing in order to achieve a better consistency with densities achieved in private sector. It allows the exclusion of schools and other free-standing G/IC facilities from the gross site area of the public housing estates to enable its site area to be more comparable to that of the private development which does not normally have these facilities. 7. A DR range between 5 and 7 had been recommended for public housing developments. This range was intended to reflect the diversity of site constraints and planning policies likely to be encountered in the Territory. For estates situated on sites with little development constraints and where infrastructure and transport facilities are adequate, the upper bound value of DR7 would be adopted. For estates situated on sites with severe development constraints such as slopes or irregular shape and where transport and infrastructure capacities are limited, a DR of 5 should be followed. In spite of the DR 5-7 guidelines, past experience has confirmed that many public housing developments were able to exceed the density threshold of DR7. This approach has been generally accepted by the Planning Department (PlanD) on a case by case basis and provided that there is adequate infrastructure to support it.
- 3 - Plot Ratio 8. The level of development for private housing (including PSPS) is guided by way of PR which is defined in the B(P)R as the gross floor area of a building divided by the area of the site on which the building is erected. To cater for a wide range of building types and different circumstances in relation to the provision of infrastructure and utilities as well as other environmental conditions, two systems of PR control have been adopted by PlanD, one statutory and the other administrative. 9. In Hong Kong Island, private housing comparable to public housing can normally be developed up to the PR limits stipulated in the B(P)R (i.e. between PR8 and PR10). In Kowloon, domestic plot ratios are restricted to a maximum under the statutory Outline Zoning Plans. 10. In order to provide a better living environment to attract residents from the main urban areas, the Land Development Policy Committee (LDPC) in November 1973 agreed that a set of density guidelines with a maximum PR5 should be applied to the new towns through administrative means. These guidelines have been used as the basis for the planning of the first generation new towns (including Tuen Mun, Sha Tin, Tsuen Wan/Kwai Tsing, Fanling/Sheung Shui, Tai Po and Yuen Long) and have been consistently applied via the leases ever since. However, due to development pressure, these administrative density guidelines have subsequently been raised to a maximum of PR8 for the second generation new towns (including Ma On Shan, Tseung Kwan O, Tung Chung/Tai Ho), which are comparable to the limits set down in the B(P)R. Definition of site 11. It is noted that the crux of application of PR controls is the definition of site. As a matter of fact, neither the Building Ordinance nor the B(P)R contains such a definition. The lack of a precise definition of a site is particularly important when PR controls are applied to public housing development. In the past, the gross site area excluding through roads would be taken as the site in calculating the PR for public housing developments. Based on this site definition, public housing developments with higher proportion of peripheral slopes and free-standing GIC uses would have high DRs (about or even exceed 7) but low PRs (may be less than 4). 12. As advised by PlanD, although there is no clear definition in the Buildings Ordinance, the site could be interpreted from a Privy Council ruling in 1982 - AG vs Cheng Yick Chi and others. Based on the court case, a
- 4 - site for the purpose of B(P)R should not take into account land which has, or would be, taken into account and used up in enabling some other developments to comply with the same Regulations. In other words, a site is equivalent to the Net Site Area as defined in Figure 1 - it should exclude schools, other GIC facilities, public open space and access roads. FUTURE DIRECTIONS 13. In the past, the choice of DR of 5, 6 or 7 would depend on the relevant constraints and opportunities as mentioned in para. 7 above. However, as a measure to increase flat production, at the 9th HOUSCOM meeting on 15 October 1997, it was determined that the concept of DR should be applied to public housing development and DR7 would be adopted as a basis for initial planning. However, every opportunity will be taken to maximize the development intensity beyond DR7 subject to resolution of various constraints like transport and other utility infrastructure capacity. 14. To implement HOUSCOM s directive the Department has attempted to maximize flat production by achieving the highest DR possible. It is, therefore, envisaged that some projects may exceed the maximum permitted under the B(P)Rs or their corresponding OZPs, if measured according to PR (according to the PlanD s advice on the definition of site ). 15. An increasing proportion of the new developments undertaken by the Department will likely be for sale or transfer (from public rental to HOS) in the future. As such, it is considered that the density of all future public housing developments should be assessed according to the plot ratio system to ensure compliance with statutory controls in the B(P)Rs and OZPs to avoid any hold up at the later site possession or land lease stage. 16. Negotiation with concerned departments, such as Planning and Lands, is currently underway to consider any technical issues which may arise from the application of PR to public housing developments, including potential impact on flat production if plot ratio was adopted. A paper on Public Housing Density Policy is under preparation by PlanD for agreement Members will be informed of the outcome in due course. INFORMATION 17. This paper is submitted for Members information.
- 5 - ---0---0---0--- File Ref. : HD(P) 10/2/4 Date : 18 May 1999