Re-issued under new categorization in August 2009 as Practice Note for Authorized
Persons, Registered Structural Engineers and Registered Geotechnical Engineers APP-28
Practice Note for Authorized Persons
Buildings Department 83
and Registered Structural Engineers
Requirements for Qualified Supervision of Site Formation Works,
Excavation Works, Foundation Works on Sloping Ground, and
Ground Investigation Works in the Scheduled Areas
Buildings Ordinance Section 17
Buildings Ordinance Section 17 explicitly empowers the Building Authority
to require ‘qualified supervision’ of certain building works when giving his approval of
plans or consent to the commencement of the works.
2. The principles used by the Building Authority in assessing the need for
qualified supervision of building works with significant geotechnical content, including site
formation works, excavation works, foundation works on sloping ground and ground
investigation works in the Scheduled Areas, are as follows :
Category (I) periodic inspections by a qualified geotechnical engineer
who was involved in the preparation of the geotechnical
content of the submission
This category of qualified supervision applies to sites
where the results of stability analyses or ground movement
calculations are sensitive to variations in the geotechnical
design assumptions. According to B(A)R 8(1)(bb), (bc)
etc, the geotechnical design assumptions must be checked
on site as works proceed. This is the first duty of the
geotechnical engineer providing the site supervision.
Having checked the geotechnical design assumptions, the
need for modifications to the design has then to be judged
by the geotechnical engineer.
Some types of design assumptions which may be critical
for stability, and which are often found by expert
inspection on site to be in error, are :
(a) the geological model (eg variation in weathering
may affect the penetration depth of steel sheet
piles); and
(b) the groundwater regime (eg occurrence of a
perched water table may impair stability).
/Category (II) ....
- 2 -
Category (II) periodic inspections by a senior qualified geotechnical
engineer who was responsible for the preparation of the
geotechnical content of the submission
This category of qualified supervision is to be imposed for
sites of high sensitivity (eg excavation sites adjoining old
buildings with shallow foundations). The personal
attention of the qualified supervisor is needed to recognise,
evaluate and communicate concerns to the authorized
person and the client at a senior level.
Category (III) full time supervision by a suitably experienced person
This category of qualified supervision applies to sites
where day-to-day checks on compliance with specifications
or working procedures are necessary. It is used for works
which depend for their success and safety on a high
standard of workmanship and materials.
Some examples are works involving ground anchors,
compaction of fill slopes, and excavation and lateral
support works involving complicated working procedures.
3. A qualified supervision package may be provided using a combination of
Categories (I), (II) and (III) above. In any case, details of the individuals who are to carry
out the supervision are to be submitted to the Building Authority for agreement.
4. The following provides guidance on the suitability of persons nominated for
compliance with qualified supervision requirements :
Category (I) - Registered Professional Engineer (Geotechnical) or
equivalent from the firm which prepared the
geotechnical content of the submission.
Category (II) - Registered Professional Engineer (Geotechnical)
who is a partner/director or equivalent of the firm
which prepared the geotechnical content of the
submission.
Category (III) - Suitably experienced qualified or graduate
engineer/geologist or technical inspector/works
supervisor, depending on the type of works.
/5. Registration ....
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5. Registered Professional Engineer (Geotechnical) is not a pre-requisite for
acceptance of persons nominated for Category (I) and Category (II) qualified supervision.
Each case should be considered on its own merits. For sites where geotechnical problems
are of a minor nature and the consequences of failure would be insignificant, the Building
Authority will normally not impose the requirement for qualified geotechnical supervision.
6. For certain sites, geotechnical supervisory requirements have been included
in the lease or land title document, and on application the sectional Chief Building Surveyor
will advise whether this is the case for a specific site.
(CHOI Yu-leuk)
Building Authority
Ref. : BD GP/BORD/32
First issued March 1982
This update December 1997 (GGE, AD/SE) - Supervision levels renamed
Index under : BO s17 - Requirement for Qualified Supervision of Building
Works with Geotechnical Content
Supervision - Building Works with Geotechnical Content
