A promising outlook in wood construction

The Microlibrary Warak Kayu is the first library in Indonesia to be made entirely of 100% SVLK-certifi ed wood (Indonesian legal wood certification) and 98% FSC-certified wood.It is the fi fth built project within the microlibrary series – an initiative to serve lowincome neighbourhoods and encourage reading in the city of Semarang. This project, a gift from the Arkatama Isvara Foundation, is the fruit of a three-way collaboration between the community, private sector and the government. Designed by SHAU Indonesia and prefabricated by PT Kayu Lapis Indonesia, this project aims to create socially performative and multifunctional community spaces using environmentally conscious design and materials.

The design process was a bottom-up one, where all available products in the factory were fi rst evaluated and the design was developed from that. As one of the design exploration results, the brise soleil was based on the “Zollinger Bauweise” – a German construction system developed in the 1920s. It is a form of reciprocal system, resulting in a distinctive slightly shifted diamond pattern. This pattern happens to resemble a local mythical creature “warak ngendog” and its dragonlike skin, displayed during annual festivals in Semarang. Hence, the name Warak Kayu in Indonesian – meaning “wooden warak” – is a positive narrative for communicating the design to a wider audience.

SPATIAL CONCEPT Architecturally, it represents SHAU’s passive climate design, material and typology experimentation in the tropical context. After numerous design iterations, the most favourable design concept was having the whole building elevated, like a traditional “rumah panggung” (“house on stilts”), because it isn’t just a library but also a neighbourhood and community centre. It is also being used to promote Indonesian engineered wood products and manufacturing capabilities. Elevating the library allows for various spatial confi gurations and the facilitation of multiple programmes and activities. On the ground, a large semi-outdoor area can be used for workshops, and a wide tribune seating at the entrance can be used for watching presentations or movies. A wooden swing is placed within to grab the attention of children. The ground area is framed by a ring of planter boxes to create an intimate atmosphere. Upstairs in the library itself, there is a net where the children can lay down, relax and read but also directly communicate with their parents and friends in the space beneath. Since reading alone is not yet considered a “fun” activity to many children, it is important to have this multi-programmatic approach to make the library a popular place.

ENVIRONMENTAL PERFORMANCE The Microlibrary Warak Kayu is designed around passive climatic design aspects: no air conditioning is used and therefore no energy is spent. According to the Köppen climate classifi cation, Semarang has a tropical monsoon climate with a temperature of up to 34 degrees Celsius during the end of the dry season. The building is cooled down using cross ventilation and solar heat is prevented from entering using shading elements. The roof overhang provides shading around noon. The longer facades are oriented north-west and south-east due to site restrictions. Therefore, an egg-crate-like deep screen – the Zollinger brise soleil – is designed to block the lower sun altitude angles in the mornings and afternoons. This means that direct sunlight cannot enter the building in an unobstructed way. As a result, the diff use-refl ected sunlight is sufficient to read books without artifi cial lighting. In addition, the depth requirement of the Zollinger brise soleil was determined by the angular relationship between the sun path and building rotation. The crossventilation aspect also helps to drag the moisture out of the building and prevents books from getting mouldy or damaged.

SUSTAINABLE AND CERTIFIED WOOD Wood as a construction material outperforms many other materials in terms of embodied energy, water and air pollution, carbon footprint, and re-

Cross ventilation allows the building to stay cool throughout the day

growth. The majority of wood materials used are FSC-certifi ed and the building can be seen as an educational spot for wood material and construction techniques. This is possible thanks to the donor and client, Arkatama Isvara Foundation, who has strong relationship with PT Kayu Lapis Indonesia, an integrated wood manufacturing company. A great variety of their available materials and products for construction are used, and the only non-wood-based materials are for the foundation, footings and roof cladding.

Bangkirai-based fi nger joint laminate is used for the main structural components

All wood materials used for Microlibrary Warak Kayu are also in compliance with the SVLK (Indonesian Legal Wood) certifi cation.

Wood is sustainably logged in Central Kalimantan, then shipped from Sampit over the Java Sea southwards to Semarang (Java) and the factory. The whole process also includes nursery, replanting and harvesting time planning to maintain sustainability for the coming years.

Various types of wood products and wood species were used. For the main structural components like columns and beams, Bangkirai-based fi nger joint laminate was used. For decking and the Zollinger brise soleil, different Meranti-based plywood types in various thicknesses were employed.

The main structure of columns, beams and secondary beams has the highest volume of all materials. Here, only Bangkirai – a tropical hardwood with high weather resistance often used for outdoor furniture and decks – is used. The byproducts of manufacturing, in the form of leftover and small-cut wood pieces, are trimmed and processed for fi nger joint strip elements. This means that the whole structural element also makes use of factory leftovers. Apart from the concrete foundation, all wooden elements are prefabricated at the factory in Semarang and transported within 20 km to the site. The prefabrication of the elements at the factory, on-time delivery and on-site assembly means less noise, dust and generally less harmful impacts on direct environment during assembly, and at the same time, faster construction time. In addition, with prefabrication at the factory, due to better trained workers, modern tools and higher safety standards, a safer construction process and higher degree of precision is reached and less mistakes are made. In general, wooden waste material produced at the factory can be collected more easily because no sorting is needed. Also, there is no distance involved in transporting waste for recycling and valuable leftovers from cutting can be used for other products consisting of smaller pieces also made at the factory. The construction of the main structural elements uses a mixture of engineered connections and carpenter joints – most notably scarf joints – for prolonging the main beams. | WIA

Architect: SHAU Indonesia (Florian Heinzelmann and Daliana Suryawinata with Rizki Maulid Supratman, Muhammad Ichsan, Alfi an Reza Almadjid, Multazam Akbar Junaedi) Structural Engineer: Joko Agus Catur Wibowo Prefabrication: PT Kayu Lapis Indonesia (Andre Sulistyo Purnomo, Dodong Budijanto Purnomo, Yosep Bayu Setiyawan) Contractor: RAH Contractor Photography: KIE & Team