When all else fails, the British secret services are the perfect excuse - and London has rolled them out as an argument against one of the most complex pieces of legislation on the EU agenda.
In theory, energy saving should be obvious and simple, especially in times of economic crisis.
In practice, it has generated multiple amendments and mathematical formulae, Byzantine even by EU standards, as governments find ways to dodge targets on increased energy savings through more efficient buildings.
One of many heated debates has focused on how many public buildings should be overhauled to make them use less energy.
The current proposal is for a proportion of the total space to be renovated each year, but EU member states have been whittling away at how many buildings should be included.
To a growing list of exceptions, Britain has added barracks and offices for the armed forces and other staff employed by national defence authorities "capable of being shared with other central government authorities", in comments on the draft directive seen by Reuters.