Lisle-Mainwaring and SSCLG v Carroll 2017 EWCA Civ 1315

From Encyclopaedia of Planning Law and Practice Monthly Bulletin (Oct 2017) “Citing the judgment of Auld LJ in R. (Mount Cook
Land Ltd) v Westminster City Council, Lindblom LJ said
that the law was clear on the circumstances in which
a potential alternative future use of the site on which
development was proposed was a material
consideration. The Mount Cook principles aligned with
“the most fundamental principle of development
control decision-making: that an application must be
determined on its own merits, in accordance with the
statutory scheme”. If the proposed development was
acceptable in its own right, the alternative proposal
was normally irrelevant. Alternative proposals would
only be material in “exceptional circumstances”, and
even then, only if the alternative was not “inchoate or
vague” and there was a “real possibility” of its being
implemented in the foreseeable future.”

R v on the Application of Mount Cook Land Ltd v Westminster City Council 2003 EWCA Civ 1324

(para 30)1) in the context of planning control, a
person may do what he wants with his
land provided his use of it is acceptable
in planning terms;
(2) there may be a number of alternative uses
from which he could choose, each of
which would be acceptable in planning
terms;
(3) whether any proposed use is acceptable
in planning terms depends on whether it
would cause planning harm judged
according to relevant planning policies
where there are any;
(4) in the absence of conflict with planning
policy and/or other planning harm, the
relative advantages of alternative uses on
the application site or of the same use on
alternative sites are normally irrelevant
in planning terms;
(5) where … an application proposal does
not conflict with policy, otherwise
involves no planning harm and, as it
happens, includes some enhancement, any
alternative proposals would normally be
irrelevant;
(6) even in exceptional circumstances where
alternative proposals might be relevant,
inchoate or vague schemes and/or those
that are unlikely or have no real possibility
of coming about would not be relevant
or, if they were, should be given little or
no weight.’