Hanoi/ The Informalization of Formal Housing

Before 1990, there were 30 KTTs built in Hanoi. The quantity was far from satisfying the rapid growth of population and the corresponding needs of housing. Meanwhile, the complexes faced the problem of maintenance due to its low rental fee, economic struggles and large scale.

Before the country entered market economy in 1990, government used strict socialist housing regulations to control private ownership, private construction and building renovation activities in Hanoi. Though since the 1990s, certain official papers from the ward are still in need, there have been enormous spontaneous renovations constructed in the KTT buildings which haven’t been demolished. Residents tried to solve the insufficiency of living space and maintenance on their own, adapting the public spaces and buildings to their daily needs.

Since Doi Moi started in the late 1980s, these socialist symbols have changed significantly. The originally monotonous buildings with flat facades have been added with ‘informal building addition’ and gone through interior renovation. The floor plans could be elongated by adding extra rooms to the front and the back of the blocks and the communal rooms could be further divided into smaller rooms. The extended structures were built by the owners themselves with recycled materials and they all have quite different decoration motifs, colors and materials corresponding to different rooms and uses. These socialist mass buildings became architecturally and culturally closer to the existing urban grain but distinctively with its poor living standards and over-high living density.

Illegal addition (Dinh Quoc Phuong, 2011)
Illegal addition (Dinh Quoc Phuong, 2011)
Informal building addition in plan (Nelobo, 2015)
Informal building addition in plan (Nelobo, 2015)


  1. Dinh Quoc Phuong (2011). The Impact of ‘Informal’ Building Additions on Interior/Exterior Space in Hanoi’s Old Apartment Blocks (KTT). Ph.D, Swinburne University of Technology, Australia.
  2. Emmanuel Cerise and Kelly Shannon (2010). Informalization of Formal Housing / Formalization of Informal Housing.
  3. Nelobo (2015).Heterotopia: Hanoi, Vietnam, 1999-2000 & 2003. Retrived at http://www.nelobo.com/travaux/05_heterotopie/05_heterotopie_eng.php.
  4. William S. Logan (2000). Hanoi: Biography of a City. Seattle: University of Washington Press

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.