Annual Concrete Seminar

Restoration of Kom Tong Hall into Dr Sun Yat-sen Museum

Architectural Services Department 18 Feb 2008

Part Plan of City of Victoria, Hong Kong 1889

The terrace house known as Lower Woodlands prior to 1914 (Source: from book “ Ho Kom Tong, A Man for All Seasons” by Frances Tze Lu )

Map sheet of Victoria 1936-46

Kom Tong Hall in its early days (Source: from book “ Ho Kom Tong, A Man for All Seasons” by Frances Tze Lu )

Aerial view of Kom Tong Hall in 2000

Kom Tong Hall in 2004

Portrait of Mr. Ho Kom Tong, brother of Sir Ho Tung and Dr. Sun Yat-sen (Source: from book “ Ho Kom Tong, A Man for All Seasons” by Frances Tze Lu )

Background (I) � Owner: Ho Kom Tong, Ho’s Family (1914-1959) Cheng’s Family (1959-1960) Church of Jesus Christ of Later-day Saint also known as “The Mormons” (1960-2004) The Government of HKSAR (2004~present)

� Architects and Interior Designers: A.C. Little, Adam and Wood, Aston Webb and E. Ingress Bell P.K. Ng Architects & EngineersArchitectural Services Department

� Architectural Features: Classical elliptical façade graced with granite columns and curved protruding balconies in a combination of red bricks with masonry is a typical Edwardian Classical features

Background (II)

� Historical Status: Accorded Grade II Historic-building, by Antiquity and Monument Office in 1990

� Site Area: 1,020 square metres � Constructional Floor Area: 2,560 square metres

� Church’s Disposal Plan: The Church wanted to demolish the Building in 1990, but was turned down by its HQ In July 2002, the Church applied for permission to demolish the Building and that provoked protests from District Council (C&W), local residents and Ho’s Family

Background (III) � The Government’s Decision: Choice for the Site of the Dr Sun Yat-sen Museum - proximity to the existing Dr Sun Yat-sen Historic Trail - both Mr. HO Kom Tong and Dr Sun studied in Central School - compatible scale in physical size - convenient location

� The Acquisition: In Feb 2004, the Church agreed in principle to surrender the Building & the Site to the Government of HKSAR

� Deed of Surrender executed on 9th June 2004 on consideration of $53 million

The Interior of Kom Tong Hall

View of grand timber stair and Stained glass window

The Tiles

IssuesThe issues are mainly technical with a view that the building would be re-adaptively used as a museum. Impact onto the existing building with the following requirement have been studied and examined, design made based on the principle of “minimum intervention” to the existing building.

1. The provision of Central Air Conditioning;

2. The provision of Sprinkler System and other Fire Service matter;

3. The Provision of sufficient Means of Escapes;

4. The provision of sufficient sanitary fittings for a museum;

5. The Provision of Barrier Free Access (passenger/disabled lift);

6. Geotechnical and structural safety.

Studies & Investigations � Measured Drawings

� Structural Survey

� Geotechnical Assessment

� Discussion with Fire Services Department

� Fire Engineering Studies

� Traffic Impact Assessment

� Conservation Plan

� Crowd Control

Questions to be addressed Are the materials and construction methods for the building structure and fabric well understood?

Is the building safe for the change of use from a residential building into a museum and is it suitable for conversion? (loading, fire)

Are there inherent defects within the structure and the fabric?

Is it expensive to carry out repair works and what will be the long term maintenance cost?

Is the rear retaining wall safe?

Adopting the minimum-intervention policy for conversion, how can we meet conflicting constraints?

The Castle Road & Woodland Terrace

The Castle Lane, Services mounted on external wall

Registered rear retaining wall 11SW-A/R839

Rear retaining wall seen from Woodland Terrace

Boundary of rear retaining wall

(Source: Appraisal of Existing Iron and Steel Structures by SCI – M Bussell)

History of structural steel

History of steel reinforcement in RC structures

First discovered by Joseph Louis Lambot in mid 1800’s – by adding thin steel bars to concrete in garden tubs and concrete beams.

First patented in USA by Thaddeus Hyatt in 1878 – popularity rocketed in early 1900’s.

Patented by a French engineer Francois Hennebique (1842-1921) in 1892 in the concrete slab with steel bars placed at its bottom face. The bars are flattened at the ends and split to form a ‘fish tail’.

The steel reinforcement has been refined over the years in terms of form, shape and quality.

Existing Structural Framing Plan

NOT FOUND

Structural Survey

The aim of the survey was to reveal the structural system, pathology of the load path, structural sizes including foundations, connection details and construction method.

The performance of the structure was then assessed by investigation of its conditions to establish load carrying capacities.

Construction and design methods were also considered alongside with the materials of the building in the context of age, past use and changes that might have occurred.

Diagnosis and identification of building defects that could betray the the performance of the structure should be reported.

Survey supplemented with sample testing by testing laboratories after initial assessment to confirm findings.

Surveyed lower ground floor framing plan

Surveyed ground floor framing plan

Surveyed mezzanine floor framing plan

Surveyed first floor framing plan

Surveyed second floor framing plan

Surveyed roof framing plan

Structural survey and building defects

Cracking of bricks due to corrosion of steelwork

Opening up to expose existing steel frame

Structural defects

Defects at brickwork

Other defects

On site testing by laboratories

Testing schedule

Cover meter and radar survey

Concrete cover to steel beams

Carbonation test

Compressive strength of concrete core samples

Chloride content of concrete core samples

Water absorption of concrete core samples

Cement content and A/C ratio

Compressive strength of brick

Summary of mortar testing

Compressive strength of brickwork

Tensile strength of steel reinforcement

Mesh reinforcement

Yield and tensile strength of structural steel

Second floor plan

Static floor loading test with water barriers

Floor beam deflection monitoring during loading test

Conversion Work

Rear lift lobby/pit

First floor framing plan

Roof framing plan

Construction

Construction of lift pit at rear of building

Temporary works for lift lobby/pit construction

Ground Floor Plan

Completed lift lobby/pit at lower ground floor

Construction of sprinkler tank and replacement garage roof

Conversion work at 60’s

Plant room at roof level

Cleaning of rust at the structural steel

Jacking of timber staircase for level correction

Timber stair at landing level

Repair work to correct level at the timber staircase

Existing roof slab construction & BS penetration

Existing strip foundations

Existing stair railing

Grand teak wood staircase

Interior after conversion

Interior after conversion

Development Programme

May 2004 Possession of Site by Government

Feb 2005 LegCo’s PWSC (Upgrade to Cat A) ~$90M

May 2005 Construction of Lift Pit & Underground Water Tank

Oct 2005 Commencement of Main Contract (11.5 months)

Nov 2006 Exhibition works

Dec 2006 Opening

Conclusions

Process of giving new life to an old building was presented with the use of the principle of “minimum-intervention”;

Background knowledge of historical materials and construction techniques are very important before we embark on conservation;

Thorough survey of building structure to ensure safety, durability and convertibility are well understood;

Be prepared to act swiftly on site for unforeseen problems.

THANK YOU