Bojonegoro is located about 110km west of Surabaya (capital of East Java) and is the capital of the Bojonegoro Regency. With that Bojonegoro is a hub for people living and working in the region. SHAU was requested by the current Regent of Bojonegoro, Kang Yoto to support their efforts of city renewal regarding several projects like waterfront refurbishment, pocket parks, Alun-Alun (Main Square) Microlibrary and rebuilding the Banjarejo market area which currently houses a traditional market (Pasar Tradisional).
The aim of the renewal project of Banjarejo market area in Bojonegoro is to improve several aspects of the current market situation. Those are logistics – delivery and waste management, parking, hygiene, climatic aspects, lighting, usability, etc. The project also consists of two design and execution phases. Phase 1 deals with the recently finished parking area and roof and the grain market. Phase 2 deals with the main market (Pasar Tradisional) and nearby Mushola (praying room). Here the idea is to build the market in sub-phases and during execution use the newly built parking roof to temporarily house parts of the market during construction periods.
SHAU did extensive research, also with the help of a group of students from Institut Teknologi Sepuluh Nopember (ITS) Surabaya to survey, map and analyze the current situation. In discussion with the city the current phasing was decided to be able to design and execute the first phase within a rather tight schedule of 3 weeks each. The boundaries for the various functions were also agreed on to be able to build each element without disturbing the other functions, mainly with respect to roads and logistics during building projects. Early on it was also decided to use steel as the main construction/structural material due to the fact of being able to construct swiftly and local construction knowledge at hand.
Phase 1 Parking area and Grain market
For the parking area, the proportion and orientation of the site was insofar optimal since it allowed for a design of the parking roof stretching from East to West, thus having the long roof line facing North and South which is better to be able to shade the space underneath. Due to extreme time limitations SHAU decided to re-use and adopt a previous design for a competition entry in Germany and after placing the 3D model into context they realized that the geometry fits in well. The woven structure of the large roof of alternating bands zig zagging along East-West direction taking up the scale of the surrounding Kampung buildings and the column system in terms of span and placement can be adopted well for the parking lots underneath. The openings on the roof are cladded with translucent, white polycarbonate and enable sunlight to enter in a diffused way during high sun altitude coming from either North or South depending on the Month. For the roof cladding, it was decided to use a sheet metal standing seem product, due to light weight properties which is coated in zinc to reflect as much heat as possible.
The grain market was already existing in form of run-down concrete buildings stretching in North-South direction flanking a street in the middle. SHAU picked up on the central street design, broadened it to grant better access for loading and unloading as well as other vehicles being able to pass by, while at the same time reserve the small strip in the middle for trees and public seating. The undulating zig-zagging roof design was picked up again but at this time interpreted as a continuous band of pitched roofs of three different heights, playing with irregularity in order to bring in variation, scale down the long building but also to break the linearity of the central street and “slowdown” and structure the open space. A roofed front porch was built with a lamella frontal façade to protect the continuous loading colonnade and facade behind as much as possible from rain and low sun altitudes. The roof is cladded in the same way as the parking roof and due to inclination and height is more visible from below. Due to this inclination and orientation it reflects the color of the sky to the visitor and appears as an aluminum wrapped Toblerone bar.
Phase 2 Main market and Mushola
For the main market, a different roofing system was developed. After several studies of references especially Pasar Johar in Semarang by Herman Thomas Karsten and the umbrella concrete structures of High Life textile factory by Felix Candela, SHAU developed their own umbrella design taking previously analyzed design features into consideration. Both examples employ daylight as one of their design features. Pasar Johar with its clearance above the market stalls implies the possibility for ample cross ventilation and the visibility of the columns from the ground level impose a certain order and structured space above the messier and less controllable market activities underneath. The self-supporting umbrella idea was picked up in order to be able to build the main market in phases. That means parts of the current market activities will be housed temporarily under the newly built parking roof, while the first part of the market is going to be built without vendors losing their income during construction. As a main structural and construction element steel was chosen due to afore mentioned reasons. The umbrellas are cladded with a system of cement board lamellas which serve several purposes. The lamellas are arranged in such a way to form an arching geometry, while simultaneously give the roof a layered more tectonic appearance. At the same time, the lamellas shade the space underneath but let daylight pass in a reduced amount and sunlight being reflected by the lamellas in a diffused way for more equal light distribution. The target was to reach about 200-300 lux of illuminance underneath on floor level at worst daylight conditions like overcast sky. This was decided based on EN 12464-1 illuminance levels norm stating to have 300 lux for retail space. Several shading and Radiance daylight simulations were made to determine the vertical distance between the lamellas and the depth of each lamella. The decision of a 40cm vertical lamella distance was made based on illumination values, architectural appearance and construction costs. The individual market stalls underneath need to be locked individually and need to be secured against theft. To let natural light pass into the stores but also hot air escape. It was decided to cover the stalls with metal crating. The whole arrangement of umbrellas is arrayed in such a way that the market stalls are set back to the inside. That serves several purposes, firstly forming and external colonnade space for people to move around while being rain protected but also bring the order of the whole roof structure to the foreground and define a permeable boundary of the market. The top of the lamellas will be cladded with glass and rainwater is intended to be collected through the central umbrella column and stored centrally to be used later for cleaning the market after opening hours. In total, there are three different types of umbrellas with different heights designed, which are placed in such a way that the highest ones are placed in the center of the market to enable the raising hot air escape to the outside via the roof.
The Mushola (prayer room) is located next to the parking area. Here a clean and simple volume with folded inwards entrances was designed. The prayer room which is facing Mekka is oriented towards an open horizontal slit stretching across the whole façade. The low wall and water feature in front of the slit, block the noise and sight from the parking lot and the moving water with is sound of sprinkling generates a peaceful ambience. At the same time air can enter there and is cooled by the water feature through evaporative cooling. Hot air similar to the market can escape via the roof. The choice of using the same umbrella system like in the market is twofold. Firstly, a unique daylighting situation from above is generated and secondly the Mushola serves as a construction prototype for the whole market. That means the Mushola gets built before the actual market and the umbrella system can be tested and evaluated on a 1:1 prototype and eventually design flaws or construction problems can be detected and improved early on.
Team Architectural Design: SHAU Indonesia, Bandung Florian Heinzelmann, Daliana Suryawinata and Tobias Hofmann with Rizki Supratman, Aditya Kusuma, Yasser Hafizs, Ryan Azhar, Roland Tejoprayitno, Muhammad Ichsan
Surveyor from ITS (Institut) Teknologi Sepuluh Nopember University Fajar Harwiansyah Dzikri , Abdi Juryan Ladianto, Firdhiansyah Fathoni,Yusuf Prasetyo
Contractor phase 1 PT. Cipta Karya Multiteknik ,Surabaya