By: John Carter, Lorenzo Taverna-Turisan (ACE) and Jean-Jacques Kriel
In 2022 the UCL Company, leaders in the sugar, wattle and timber industry in the KZN Midlands, branched out into the fruit growing and packing industry by commissioning their project team to design and implement a unique facility near the town of Dalton, in line with the highest standards in the global industry.
Typically packing facilities are designed to accommodate a single commodity, or at least similar ones, which was not the case for the UCL packhouse. Rather, their brief was to pack both avocados and kiwis in the same facility, which led to them creating very specific protocols in terms of product flow and refrigeration solutions to suit both commodities in the same facility.
“The combination of logistics, post-harvest treatment, sorting and packaging processes, statutory requirements, local by-laws, export compliance and food safety have evolved this building typology into a complex and specialised field of architecture.”
Project dimensions & challenges
Long gone are the days when one could simply erect a ‘plaas stoor’ or farm storage and install a pack line. Considering the high-quality and statutory standards required to export fruit to the various global markets and the complexity of packing both avocado and kiwi in the same packhouse, the building also needed to take into account the various export protocols. These differ from one country to another – for instance, the UK and EU, and Eastern markets like China. They demand segregation of the fruit once packed, as well as different draw-down applications in cold storage. The combination of logistics, post-harvest treatment, sorting and packaging processes, statutory requirements, local by-laws, export compliance and food safety have evolved this building typology into a complex and specialised field of architecture.
The raft foundation – a functional solution to a pressing problem
Each packing facility is unique, and UCL was no exception. Challenges started with the poor soil conditions, which is perfect for the sugar cane previously cultivated on the site, but not for construction. The combination of the significant slope of the site and its high clay content required the implementation of a raft foundation. This allowed the use of in-situ material from the site, instead of carting away and importing fill amounting to +- 30,000m3 to and from a site about 9km from the premises. The decision was based on both the cost of importing the material, and the impact that such a high volume of trucks carrying fill would have on the roadways to the borrow pit.
The benefit of the raft foundation would be seen later in the construction process, where the contractors had a solid base to work from overhead. However, this came at the cost of having to ensure all subsurface services were installed prior to the raft slab being placed.
This was achieved by implementing BIM software to coordinate all aspects of the building and accurately issuing this information to the contractors in both 2D and 3D BIM platforms. An example of this is the drainage services, which are labelled and referenced back to a known benchmark and global coordinate system in X,Y and Z Axis, which in turn allowed a surveyor to set out all services on the site before any building references were set up.
The implementation of the BIM was applied to all aspects of the building, including structural steel, refrigeration equipment, fire water, electrical main reticulation, plumbing and others, to the extent that the BIM Model is an accurate virtual version of the actual building on site. This allowed Bespoke Agri-tects (a division of Bespoke Architects), as the architects of the packing facility, to identify and solve collisions between services in a virtual environment prior to the problem being found on site. In turn, this saved time and costs by preventing later remedial work or alterations to solve collisions. A further benefit of applying this tool is that the contractor has a 3D version of the building to use as reference on-site when a detail on a drawing or connection might not be immediately visible on a 2D document.
Microclimates addressed
Taking into account the building type and export market the client intended to service significantly influenced the composition and pallet of materials used. The commodities packed require very specific protocols in terms of area segregation and temperature control in order to maintain product shelf life and comply with export cooling regimes.
For this reason, there are four temperature areas: ambient; cooled; pull down refrigeration, and holding refrigeration. Each area requires an efficient, yet cost effective solution to maintain the desired environment.
The first microclimate is the ambient space, in this case, for receiving fruit and packaging materials. Receiving areas generally do not need to be temperature controlled. In these areas, a typical combination of roof sheeting with a radiant barrier and side cladding is sufficient, where the carton store envelope is a 120-minute, fire-rated masonry wall. All side cladding was 0.53 ZincAl AZ150 Colorplus Textured Thunderstorm, rolled into a Trimflute profile, colour to broad flute, to allow the fixing of the sheeting to the girts to be done inside the inverted rib and against the purlins, allowing for a more securing fixing method, and also hiding the screw head to some extent on the elevations.
The packing area of UCL Packhouse required a unique solution due to the temperature regulated environment, which also needs to allow natural light into the building in both the summer (for kiwi) and winter (for avocado) seasons. Dalton can reach very high summer temperatures and receive snow during the cold winters, necessitating a specific application of materials to address both conditions. The bespoke solution to this problem was to apply a composite roofing solution of concealed fix sheeting (Saflok 0.53 ZincAL AZ150 Textured Colorplus) with rigid roof insulation (40mm Lambdaboard) installed between purlins, combined with an 18mm Palram Sunpal polycarbonate panel applied vertically on the North elevation to allow natural light into the space while maintaining a controlled temperature internally.
BIM precision
The roofing composite was again coordinated using the BIM and IFC software to provide pre-drilled purlins as fixing points for the roof sprinkler installation. As part of the design process, Bespoke always takes into account how the building will be erected in very tight timelines, so they anticipated that the roof sheeting and insulation would be installed prior to the sprinkler pipes, which limits the access for fixing sprinkler hangers. The solution was to pre-drill the purlins, install the hanger rods as part of the roof installation, then sheet the roof, allowing the sprinkler pipes to be installed thereafter. This provided a very clean installation of overhead services and is particularly important as the building and pack line equipment are considered a unit, hence the paint colours of all steel and services were matched with the colour pallet received from the equipment suppliers.
Considering the two fire escape stairwells placed on the northern façade, Bespoke decided to treat them as architectural elements by applying red insulated Sunpal panels to these elements, as opposed to the opaque panels of the rest of the façade. This creates a very unique lighting quality in these areas, but also makes the fire escapes highly visible from anywhere in the packing area.
Purpose-made insulated panels with grey fluted faces to the external façade and toward the packing area were installed to complement the colour palette of the interior space. These rooms were placed on in-situ concrete plinths as constructed using permanent 3CR12 stainless steel shutters. This protects the panels from forklift collision and also raises the panels from the floor to prevent oxidation and corrosion caused by condensation collecting at the base of the panel.
Refrigeration protocols differ between the two commodities, which require holding areas of various size and function. This facility has been designed to accommodate two separate cold chains from packaging to dispatch in the event of varying export standard protocols.
Structural framing & envelope
Structural framework was determined by a few functional factors but primarily, by the pack line. Racking in cold storage and forklift movement are the influencing factors when designing these structures.
Form and structure follow function; the column positions are placed in areas where no equipment is required, resulting in alternating grid spacing to accommodate the small tolerances between equipment and structure. The pack line equipment complexity further influences escape routes and flow patterns within these buildings, which require innovative and integrated design solutions between the building team and pack line team to create a homogenous solution.
Roofing solution aids function but also form
All materials and design elements on the building envelope were determined by a functional aspect relating to either climatic or environmental elements. The roof sheeting for example was chosen primarily for the Saflok 700, which allows a much lower roof pitch and continuous sheeting lengths. These, in turn, facilitate a more cost-effective span to volumetric ratio. The challenge with such long sheets on a sloping site is the natural spring in the material causing oil canning, the wavy distortion in the flat areas of metal cladding and roof panels. This was overcome by using the Colorplus Textured sheet. This also hides the bagasse sediment from the sugar cane surrounding the site. Very few horizontal areas are left exposed; this is to prevent the accumulation of the begasse, which causes a building to age quickly, so sloped surfaces are dominant in the design elements.
Services
In terms of services, these was dealt with in an industrial manner to allow for ease of maintenance and to reduce risk in the event of the failure of an installation, as it would be nearly impossible to repair any subsurface services below the raft. Services corridors were created in accessible areas and limited to the perimeter of the building as far as possible.
Project team
Client: UCL Company
Architect: Bespoke Agri-tects (Division of Bespoke Architects)
Principle Agent / Consultants: Feroqs Consult
Quantity Surveyor: Feroqs Consult
Packling Consultant: Packline Solutions
Civil Engineer: Kantey & Templar
Structural Engineer: Stance Consulting
Electrical Engineer: CPP Marepo
Fire Engineer: ASP Fire
Building Contractor: Robertson & Poole Construction
Structural Steel Contractor: NJW Engineering
Refrigeration Contractor: ES Engineering
Roofing Contractor: MJC Industrial
Fire Contractor: FireCo
Packline Equipment: Tomra / Masgcor / Gossamer
Content by: John Carter M.Arch (FS) Pr.Arch of Bespoke Architects (Pty)Ltd.
