5 Reasons BHU Certification
Applications Fail
Five issues account for the majority of BHU certification rejections in Hong Kong. Every rejection adds 8–16 weeks to your timeline — critical context given the March 2027 enforcement deadline.
- Ventilation failures are the leading cause of rejection — particularly for inner units with no window
- Floor area below 8 sq m and ceiling height below 2.3 m (measured at lowest point) are structural issues that must be assessed on-site by an Authorized Person
- Document errors — property details mismatched against Land Registry records, missing ventilation calculation sheets — cause rejections even when the unit is physically compliant
The 5 Most Common BHU Rejection Reasons
According to the Buildings Department's BHU Code of Practice and Owl Square Group's application records, these five issues account for the vast majority of certification rejections.
Timeline Cost of Each Rejection
According to the Buildings Department's processing records, each BHU-01 resubmission requires a fresh review cycle:
One rejection can push back the certification completion date by 3–5 months. With the March 2027 enforcement deadline approaching, this delay is a material risk for landlords who have not yet begun the process.
3 Steps to Reduce Rejection Risk Before Submission
Engage an AP with a proven BHU-01 track record
An AP's practical experience with the Buildings Department's submission requirements directly affects rejection rates. When selecting an AP, ask specifically about their number of BHU-01 submissions and rejection history. According to the Buildings Ordinance, the AP signs and is professionally responsible for the application.
Conduct a full compliance assessment before any works
A complete assessment covers all five rejection risk areas: floor area and ceiling height measurements, ventilation calculations, fire safety inventory, and owner details against Land Registry records. Any issue identified at assessment stage is far cheaper to resolve than a post-rejection resubmission.
Independent document check before submission
The Form BHU-01, ventilation calculation, floor plan, and authorisation letter should all be cross-checked by a second reviewer before filing. Pay particular attention to: owner name consistency with Land Registry, property address format, unit identification number, and all signature fields.
Frequently Asked Questions
What is the most common reason BHU certification applications are rejected?
According to Owl Square Group's application records, inadequate ventilation is the most frequent cause — particularly for inner units with no direct external window. It is followed by insufficient floor area (below 8 sq m), missing fire safety installations (no FD30 fire door or independent smoke detector per unit), documentation errors, and ceiling height below 2.3 m.
How long does it take after a rejection before you can complete certification?
After a rejection, the Buildings Department requires 8–16 weeks to review a corrected resubmission. If the rejection requires physical renovation works, those add another 2–6 weeks. One rejection typically delays the final certification date by 3–5 months.
What happens if my unit's floor area is only 7.8 sq m?
Two options are available: merge the unit with an adjacent undersized unit to reach 8 sq m combined (HKD 30,000–80,000); or assess whether a non-load-bearing partition wall can be repositioned to expand the floor area (HKD 15,000–40,000). An Authorized Person must assess feasibility on-site. If neither option is viable, the unit may not be eligible for certification.
Can a landlord submit the BHU-01 application themselves?
No. According to the Buildings Ordinance, Form BHU-01 must be signed and submitted by a qualified Authorized Person (AP) — an architect, engineer, or surveyor on the Buildings Department's registered list. The AP bears professional responsibility for the submission.
Is there a way to check if my unit will pass before submitting?
Yes — a full compliance assessment by an AP before submission is the standard approach. The assessment covers all five common rejection areas, provides written findings, and recommends remediation works where needed. This is the most cost-effective risk mitigation before filing.