Retrofitting buildings

The need for Supplementary Planning Guidance on Viability Assessments

Date published: 
01 February 2016

The London Assembly Planning Committee has written to the Mayor to express concern that the planning system in London is too easily manipulated to maximise developer profits.

The Committee has found that some developers are deliberately paying too much for land, to make providing affordable housing unviable, with several hiding behind confidential viability assessments. The Committee is also concerned some developers are overvaluing their costs and undervaluing the final scheme’s value.

A range of measures are recommended to ensure a more balanced, transparent and fair system - including:

  • Measuring the value of land according to its existing value, rather than its potential value. For example, if the land was developed into luxury flats.
  • Promoting the idea that developers should be open and transparent in publishing their deals
  • Developing planners’ skills and setting an example on public land to challenge false assumptions that affordable housing is too costly to build.