Expandable House

Residential, Social / 1st Quarter 2019

Expandable House

The expandable house (rumah tambah in Bahasa Indonesia, or rubah for short) is a component of the Tropical Town project, and is designed as a sustainable response to the challenges of rapidly developing cities in monsoon Asia.

The expandable house adjusts to the fluctuating patterns of resource consumption and expenditure, or metabolism, of its residents. This includes the influx of young migrants from all over Indonesia—so how would the city accommodate this inflow by way of housing, amenities, etc.? In practical terms, this means understanding the patterns of household income generation and expenditure, water, energy and food consumption, as well as waste production. Rumah tambah focuses on the challenge of housing by allowing the base to be flexibly configured. A prototype of the expandable house has been constructed in Batam, with the support of the community of Kampung Tua Melayu, where a field laboratory is located.


The expandable house is designed around six principles:

1) Seeding 

Seeding common technologies (rainwater and septic tanks, filters, sensors), material strategies (renewable, available, emergent) and spatial planning parameters (street widths, density standards) to catalyse the growth of variable built fabrics and diverse tropical towns. 

2) Sandwich Section 

A hoistable roof and fixed foundations (the ‘bread’) that can support up to three additional floors (the ‘filling’), allowing for flexible financing, where the developer or state housing agency provides the roof and foundations, and the residents construct extra space as their circumstances require and budget allows. It also helps to accommodate crucial income generating functions (shop, café, mechanical repairs, cottage industry) along with the dwelling.

3) Productive Landscapes 

Integrate food and building material production capacity locally, such as bamboo plantations and kitchen gardens, to help further diversify the resource base of the residents. 

4) Public and Private Spaces 

Integrate a spectrum of public and private spaces (squares, streets, laneways, courtyards) and thresholds between them (gateways, balconies, porches, vestibules) that support a good living experience in dense and mixed-use urban environments. 

5) Decentralised Systems 

Plan with decentralised systems—rainwater harvesting and solar electricity generating technologies, sewage and septic tank systems, as well as passive cooling principles—to avoid or supplement expensive and often unreliable centralised or ‘big pipe’ infrastructure. 

6) Density and Scalability 

Encourage vertical densification to benefit from the co-location of dwellings and employment, reduce the settlement footprint on arable land, and the demand for expensive infrastructures (roads, electrical and potable water networks).

Project Name Expandable House
Location Batam, Indonesia
Completion Date November 2017
Site Area 60 square metres
Gross Floor Area 36 square metres
Building Height 3 metres
Collaborator/Owner Community of Kampung Melayu
Batu Besar, Batam
Design Firms Future Cities Laboratory (FCL);
Singapore-ETH Centre(SEC)
Principal Architect Stephen Cairns
Project Team Urban-Rural System, Future Cities
Laboratory (FCL)
Mechanical & Electrical Engineer Azwan Aziz
Civil & Structural Engineers Philipp Müller; Teddy Tambunan
Images/Photos Dio Guna Putra

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