This site with a proposal for 200 dwellings is a sensitive site for development. The NHDC Land Sensitivity and Capacity Study Report - Planning Policy and Projects, November 2006 identified only three Knebworth sites with low sensitivity and high capacity. In each of the three cases the report states "these sites have been appraised as being able to accommodate new housing development without significant effects on their character or the surrounding landscape." KB4 is not one of these sites.

The NHDC Land Allocations - Additional Suggested Sites July, 2009 highlighted the site's weaknesses as:

i. Green field site as grade 3 agricultural land

ii. Site in groundwater protection zones 1 and 2

iii. Identified constraints on utilities and capacity of primary school.