Statistics on the errors in appeal decisions relating to Part 1 of the GPDO …

The Planning Jungle website has calculated the percentage of appeal decisions relating to Part 1 of the GPDO that appear to contain at least one interpretation of the legislation that was subsequently shown to be "incorrect".  The statistics are as follows:

Appeal decisions issued BEFORE the DCLG "Technical Guidance" document (August 2010):

  • 27% of appeal decisions (35 out of 129) issued between October 2008 and August 2010 appear to contain at least one "incorrect" interpretation of the legislation.

Appeal decisions issued AFTER the DCLG "Technical Guidance" document (August 2010):

  • 13% of appeal decisions (48 out of 369) issued between August 2010 and November 2013 appear to contain at least one "incorrect" interpretation of the legislation.

ALL appeal decisions (i.e. includes all of the above):

  • 17% of appeal decisions (83 out of 498) issued between October 2008 and November 2013 appear to contain at least one "incorrect" interpretation of the legislation.

Notes about the above statistics:

  • The above statistics were calculated by looking at all of the examples within the "Part 1 of the GPDO - Appeal Decision Summaries" document of where one group of appeal decisions contradicts another group of appeal decisions.  For each such example, it was assumed that the group containing the DCLG "Technical Guidance" document (where applicable), or the group containing the most appeal decisions (in all other cases), is the "correct" group, and that the other group is the "incorrect" group.
  • As an exception to the above method, the group of appeals that was shown to be incorrect by the High Court judgment on 18/06/2013 is now taken to be the "incorrect" group, even though it contains the DCLG "Technical Guidance" document.
  • It's important to note that the above method is a relatively conservative method that is likely to underestimate the percentage of appeal decisions that contain at least one "incorrect" interpretation.  As an example, if there are 6 appeal decisions that support a particular interpretation versus 3 appeal decisions that support the opposite interpretation, then the above method would assume that the majority (i.e. 6) are "correct" and the minority (i.e. 3) are "incorrect".  As another example, if a group of appeal decisions hasn't been contradicted by any other appeal decisions, then the above method would assume that this group is "correct".  In other words, the above method would generally minimise the number of "incorrect" appeal decisions.
  • It should also be noted that the conclusion that an appeal decision contains at least one incorrect interpretation is not necessarily the same as the conclusion that the outcome of the appeal was incorrect.  For example, if an appeal is dismissed for two reasons, one of which is incorrect, then the appeal decision would contain an incorrect interpretation but the outcome of the appeal would be correct.
  • The above statistics relate to all of the appeal decisions that have been summarised within the "Part 1 of the GPDO - Appeal Decision Summaries" document as of 25/11/2013, excluding the 21 appeal decisions relating to applications for prior approval under Part 1 of the GPDO.
  • It's important to note that the above statistics are based upon the assumption that all of the advice within the DCLG "Technical Guidance" document (other than the advice about the 20cm set-back from the eaves) is correct, which is not necessarily an accurate assumption (e.g. as highlighted by the High Court judgment on 18/06/2013).  If other parts of the DCLG "Technical Guidance" document are also shown to be incorrect (e.g. by future court judgments), then the above percentages of "incorrect" appeal decisions would be likely to increase, because since August 2010 most appeal decisions have followed the advice within the DCLG "Technical Guidance" document.