The BHU Code of Practice: 8 Key Areas Explained
Cap. 658 Schedule 1 defines the 8 minimum standards every subdivided unit must meet to become a certified Basic Housing Unit. The Code of Practice tells specified professionals exactly how to inspect and measure against those standards. This guide breaks down each area — and where landlords most often get it wrong.
- The BHU Code of Practice implements Cap. 658 Schedule 1's 8 minimum standards — it is what specified professionals use when inspecting your flat.
- Most commonly failed: toilet must have all 3 fixtures (flush toilet + washbasin + shower/bath); mechanical ventilation must achieve 5 air changes per hour; electricity meters must be issued by CLP Power or Hongkong Electric — an electrician-installed sub-meter does not comply.
- The specified professional must conduct an on-site inspection under s.17(2) of Cap. 658 — a report based solely on documents or photos does not meet statutory requirements.
| No. | Area | Key Requirement | Common Mistake |
|---|---|---|---|
| 1 | Internal floor area | ≥ 8 sq m (toilet included) | Thinking bathroom area is measured separately |
| 2 | Ceiling height | ≥ 2.3 m floor-to-ceiling; ≥ 2 m below beams | Ignoring that false ceilings count as the ceiling |
| 3 | Fire safety | FD30 fire door; annual detector inspection | Installing detector but skipping mandatory annual checks |
| 4 | Loading | Must not exceed proper load capacity | Adding heavy partitions without structural check |
| 5 | Exclusive toilet | Flush toilet + washbasin + bathtub/shower (all 3) | Having only toilet and washbasin, no shower/bath |
| 6 | Water supply outside toilet | Supply point AND sink outside toilet | Thinking the in-toilet washbasin counts |
| 7 | Lighting & ventilation | Option A natural / Option B mechanical (5 ACH) | Assuming any window satisfies Option A |
| 8 | Water & electricity meters | WSD water meter; CLP/HK Electric meter per unit | Using electrician-installed sub-meter instead |
Source: Basic Housing Units Ordinance (Cap. 658) Schedule 1 and Code of Practice
Areas 1 & 2: Floor Area and Ceiling Height
Under Cap. 658 Schedule 1 s.1, the minimum internal floor area is 8 sq m measured from the inner face of the enclosing structures — the toilet area is included, not measured separately.
- 8 sq m: measured from inside walls (inner face of surrounding structures), toilet included per s.1(2). The Housing Bureau does not accept building plan figures — on-site measurement by a specified professional is required.
- Ceiling height 2.3 m: measured floor-to-ceiling; false ceilings count as the ceiling. Under beams the threshold is ≥ 2 m. Both apply throughout the unit.
⚠️ Common Misunderstanding
"My rates notice shows 8.8 sq m, so surely I'm fine?" — Rateable value area and the ordinance's measurement method differ. The rateable value is calculated using a different methodology and may not correspond to the internal floor area under s.1(2). On-site measurement by a specified professional is the only valid check.
Section 17(2) of Cap. 658 states that unless a report is prepared on the basis of an on-site inspection of the principal flat (including the subdivided unit) conducted or arranged by the specified professional, the report is treated as not meeting the application requirements. A document-only report does not satisfy the statutory standard.
Areas 3 & 4: Fire Safety and Loading
Schedule 1 s.3 sets out four fire safety requirements, plus two ongoing obligations that many landlords overlook after certification.
The four requirements: (a) prevent fire spread within and out of the principal flat; (b) adequate fire and smoke resistance; (c) adequate escape routes; (d) structural stability.
In practice, this means:
- An FD30 fire door with self-closing mechanism at each unit entrance to the common area.
- An independent fire detector in each unit AND in common areas — must be inspected at least every 12 months (statutory requirement, not optional).
- A fire extinguisher in common areas — must be inspected at least every 12 months.
- The Housing Bureau — not the Buildings Department — administers BHU fire safety compliance under Cap. 658. Do not conflate this with BD requirements for other purposes.
⚠️ Certification Is Not a One-Time Event
The annual inspection obligation for fire detectors and extinguishers continues throughout the full 60-month validity period. Inspection records should be retained in writing. Failure to maintain compliant fire safety arrangements may affect the validity of the BHU certification.
Loading (s.4): the unit must not exceed its proper load capacity. Landlords planning to add heavy partition walls, cabinetry or equipment should obtain a structural check before works begin — undisclosed structural changes can complicate re-certification.
Areas 5 & 6: Toilet Fixtures and Water Supply Outside the Toilet
Schedule 1 s.5 requires the toilet to be enclosed, waterproofed, and exclusive to the occupant — and to contain three specific fixtures.
The three fixtures are all mandatory:
- (a) Flush toilet
- (b) Washbasin
- (c) Bathtub or shower
⚠️ The Single Most Common Reason Applications Are Returned
Missing a shower or bath is the single most common reason BHU applications are returned. A toilet containing only a flush toilet and washbasin does not meet the standard. Retro-fitting a shower involves drainage and waterproofing works — budget for this in any renovation plan before engaging a specified professional.
Area 6 (s.6) — water supply outside the toilet:
- A water supply point AND a wash sink must be provided outside the toilet enclosure.
- The surrounding area at the water supply point must be waterproofed.
- Common misunderstanding: the washbasin inside the toilet does not satisfy this requirement. The ordinance requires both: the 3-fixture interior toilet, plus a separate water supply point and sink outside the toilet. A kitchen sink qualifies if it is located outside the toilet space.
Areas 7 & 8: Ventilation Options and Utility Meters
Each room (including kitchen, excluding toilet) must meet one of two ventilation options. Getting this wrong is the most common technical failure at certification.
Option A — natural ventilation: complies with Buildings (Planning) Regulations (Cap. 123F) regs 30–33. This requires adequate openable window area to the exterior — not every window qualifies. A window that faces a light well, enclosed shaft or internal corridor may not satisfy the regulation.
Option B — mechanical ventilation: requires:
- (i) At least one openable window of ≥ 0.1 sq m glass area with adequate access to the exterior;
- (ii) Artificial lighting; and
- (iii) A mechanical ventilation system supplying fresh air at ≥ 5 air changes per hour (5 ACH).
Toilet ventilation: Option A per reg 36, or Option B mechanical at 5 ACH. For Option B, no window is required for the toilet.
⚠️ Calculating Whether Your Fan Is Sufficient
5 ACH means the system must exchange the full room air volume 5 times per hour. For a 10 sq m room at 2.3 m ceiling height (23 m³), that requires ≥ 115 m³/h. A standard small extractor fan rated at 80–100 m³/h may fall short. The specified professional will calculate the required capacity based on your actual room volume — do not assume any installed fan complies without a calculation check.
Area 8 — water and electricity meters:
- Water meter: must be provided by the Water Supplies Department specifically for the subdivided unit (i.e. a separate WSD account, not a sub-meter tapped from the principal flat's main supply).
- Electricity meter: must be provided by CLP Power or Hongkong Electric specifically for the subdivided unit. The meter must be supplied, installed, registered and billed by the utility company.
⚠️ "I've Installed a Sub-Meter" — This Does Not Comply
Schedule 1 s.8(b) requires the electricity meter to be "provided by CLP Power Hong Kong Limited or The Hongkong Electric Co., Ltd." specifically for the subdivided unit. An electrician-installed internal sub-meter does not meet this test — it is not issued or registered by the utility company. Landlords must apply to CLP or HK Electric for a separate supply account and metering for each unit. The application process can take several months — speak to your consultant before starting renovation works.
Frequently Asked Questions
What is the difference between the BHU Code of Practice and Schedule 1 of Cap. 658?
Schedule 1 is the statutory minimum — it sets the thresholds (8 sq m, 2.3 m ceiling, the three toilet fixtures, 5 ACH, etc.). The Code of Practice, issued under s.84(1) of Cap. 658, provides the implementation detail that specified professionals use when conducting inspections: measurement methodology, material specifications, ventilation calculation methods, and what documentary evidence the report must contain. The Code sits below the ordinance in legal hierarchy but is the operational standard in practice.
Does the toilet in a BHU need a shower or bath — or can it just have a toilet and washbasin?
All three fixtures are required. Schedule 1 s.5(2) of Cap. 658 lists: (a) flush toilet, (b) washbasin, and (c) bathtub or shower. All three must be present. An enclosed toilet with only a flush toilet and washbasin does not meet the standard. This is one of the most common reasons applications are returned.
Why doesn't an electrician-installed sub-meter satisfy the BHU electricity meter requirement?
Schedule 1 s.8(b) of Cap. 658 requires the electricity meter to be "provided by CLP Power Hong Kong Limited or The Hongkong Electric Co., Ltd." specifically for the subdivided unit. The meter must be supplied, installed, registered, and billed by the utility company — establishing a direct supply relationship. An internal sub-meter installed by an electrician does not meet this test. Landlords must apply to CLP or HK Electric for a separate metering account for each subdivided unit.
Can the specified professional base their report on photos and plans, without visiting the flat?
No. Section 17(2) of Cap. 658 states that unless the report is prepared on the basis of an on-site inspection of the principal flat (including the subdivided unit) conducted or arranged by the specified professional, the report is treated as not meeting the application requirements. On-site inspection is a statutory prerequisite.
If my flat uses Option B mechanical ventilation, how do I know if 5 ACH is sufficient?
Calculate the room volume (floor area × ceiling height in metres) and multiply by 5. The result is the minimum fresh-air supply volume in m³/h the system must deliver. Example: a 10 sq m room at 2.3 m height = 23 m³ × 5 = 115 m³/h required. Compare this with the fan's rated airflow (shown on the product label or data sheet). Many standard bathroom extractor fans rated at 80–100 m³/h fall short for larger rooms. A registered M&E engineer or the specified professional should verify the specification as part of the assessment.