Public Health Laboratory Centre
Technical accommodation

Architectural Services Department's close cooperation with the client on the Public Health Laboratory Centre project at Shek Kip Mei has resulted in a building that holds all necessary technical requirements in a tidy and user-friendly package.

When it opens next year, the building will house public health laboratories centralised after decades of being spread across the territory. The Nam Cheong Street site was chosen as a convenient location for receiving samples from health centres city-wide, and 90 per cent of space will be occupied by the Department of Health. A small portion of the development is allocated to the Department of Food and Environmental Hygiene.
        The Centre houses 130 functional rooms for clinical testing of samples and specimens. Several levels of laboratories are provided, with Level III facilities for handling more dangerous infectious diseases being the most critical. Additional provisions in the 15-storey building are support offices and ancillary facilities including sterilisation rooms, cold rooms and incubation rooms as support functions for the labs. A multi-function hall, conference room and 100-space carpark round out the development.
        The greatest challenge presented to the Architectural Services Department design professionals was how to systematically analyse the operational requirements and house them in a building that fits into the site and yet still is architecturally interesting. A schedule of accommodation for the labs and building services was received from the client and a list of requirements for each room was provided. Volumes of information were subsequently collected and functions were analysed to devise a framework under which the building owners could run services efficiently.
        Though the irregular site includes a curved edge, rectangular forms were chosen for the building's L-shaped floorplates. The shape allows for a useful internal functional layout and takes into account that a large amount of equipment going into the building, including fume cupboards, safety cabinets and refrigerators, are squarish on plan. To address the site curvature as well as noise coming from an adjacent flyover, the multi-purpose hall fills out the land and, as it needs no windows, is unaffected by noise pollution. Plant rooms are also placed to the lower edge of the building.
        Lower floors of the building house offices while the laboratories are placed on the floors above. The layout was in part determined by the need for individual fume cupboards to carry toxic gas exhaust from the labs, for which the pipes to the rooftop treatment plants need to be as short as possible. The more dangerous labs are located on the upper floors so the travel of contaminated air in the pipeline is reduced to a minimum. At the top of the building, electrical and mechanical facilities take up the equivalent of two full floors in a 4.5-metre ceiling height with four levels of access routes.
        The building exterior features predominantly light, neutral colours for an image that suits the professional staff working inside, unlike the warmer colours chosen for many public buildings. External walls are white-, grey- and sand-coloured and feature a range of textures. Plant rooms at the base and top of the building feature louvre walls to conceal machinery and add horizontal line texture. The prominent use of lines on the facades is supplemented by horizontal and vertical fins. These are designed to be thick for sunshading use, complementing other energy saving features within the building such as heat exchangers, systems to avoid dangerous emissions, high-efficiency lighting and small windows for a better OTTV (Overall Thermal Transfer Value).

The interior
Lab facilities are placed along the windows as this is where the majority of the staff will spend their working hours. Because of stress on the eyes due to microscope use, it is hoped that looking out to the site's good views will offer welcome relief for staff. Supporting facilities such as refrigeration rooms and washing areas are located in the centre of the floors, as the lab technicians would spend relatively little time at them.
        The client was concerned about circulation between the public and lab workers, and how the samples are collected and distributed to each lab. Security controls near the main passenger lift lobby on each floor separate the corridors to the labs and service lift areas. A service corridor allows for specific maintenance access to supporting facilities without disturbance to lab staff. Specimens are received at a specialised samples collection counter at the ground floor of the building, where an isolated area near the carpark is provided for staff to unpack and carry out sorting close to the loading lift.
        The architect notes that almost one third of space inside the building goes towards E&M provisions. Services installations pass through the building in vertical pockets of pipe ducts attached to each lab. Because of the nature of the building, the client specified 100 per cent air extraction from the labs. Once an individual lab's fume cupboards are operating, another ventilation system is triggered to correct for lost air pressure. A pressure difference is also maintained between the corridor and labs, maintaining negative pressure in the rooms to ensure air does not flow out into the circulation areas.
        Operational problems that needed tackling mostly related to air pollution and waste disposal. For effluent disposal, organic and inorganic waste is divided. The latter is sometimes disposed through the lab sinks, diluted and taken to a neutralisation tank. The tank has a sensor to test the pH value of the waste -- when it is too alkaline, acid will be added to neutralise the waste before disposal.
        The chosen system for handling fumes benefited from working closely with the Architectural Services Department building services engineer to conceal and arrange services. After air extracted through fume cupboards is filtered, treated and dehumidified, it must be expelled from the premises. The designer was advised early in the project that a three-metre-high chimney would be required for each of the fume cupboards. The unappealing possibility of grouping the outlets into 20 or 30 clusters of chimneys was raised but ultimately the BSE specified a Canadian air jet fan system -- a high-power unit that blows exhaust in an invisible air column up three metres before dispersion. The solution not only removed the prospect of a forest of metal chimneys above the building but presents a much more favourable image for the building to nearby residents. Along with the bag-in/bag-out HEPA filtering system for Level III labs and animal houses, the exhaust system is a first for Hong Kong.
        Finishes within the building adopt a range of materials, including wood panel and granite. Lift lobbies feature glazing to open up the spaces to the views and add some transparency to the design, as do the steel staircases located adjacent. Graphics and artworks are currently being commissioned for the building and will be put in place by the time the labs become operational early next year. Noting that the building has great potential for an image of its own, the architects are looking towards art inspired by the colours and shapes witnessed through the microscope. The designers have also put out a call to lab staff for their old equipment, with an eye to creating inspirational and historical displays.

The system approach
Faced with meeting a very complicated set of lab functions, the architect adopted a system approach not only for the labs but for the furniture too.
        Each of the labs in the Centre is different. Working with the client to determine what was needed for each lab, the designers came up with a grid framework based on a single module measuring 3.6 m by 7.2 m. The module size was derived by allowing for lab benches on each side of the space and a working bench for handling documents, charts or entering data by each window. The 3.6-metre width offers room for two lab technicians sitting on high chairs and comfortable space for a sample trolley to pass behind them while the 7.2-metre length is a multiple as well as a good depth natural light can still reach without getting too dim. The module, which includes sinks and cupboards is repeated in double, triple and quadruple configurations with different setups to suit needs. The small-sized windows allow for partitioning up to the building's perimeter with better seals between rooms.
        To accommodate a diverse range of uses, a flexible lab furniture system was needed that has outlets for water, gas and electricity in whatever combination needed. The designers decided traditional furniture was not suited and system furniture was chosen. The German-made standard units are designed to feature all elements necessary for flexible use and have all pipes preinstalled in the factory before shipping and connection.

-- Building Journal