The NLE noise standard is virtually 100% louder than standards abroad

The proposed Northern Line Extension maximum noise standard for residential properties does not compare well to other countries in the developed world or other projects in England.

The best standard is  32 dB in  Norway. The Northern Line Extension proposed level of 40dB is almost 100% louder (10dB over is a doubling in perceived loudness)

I have listed here the ones I have found in reverse chronological order of their use (all values are Lamax for ground-borne noise):

Northern Line Extension:    40dB   (June-2011)
Dublin:                                  35dB   (Application Oct. 2010) document
Australia:                              35dB   (June 2010) document p. 8 (35dB night and 40 dB day)
Crossrail:                              35dB   (April 2008) document
Norway:                                32 dB  (prior to 2005) document
USA:                                     35dB   (since April 1995) document (day and night)

The picture that is emerging is an international alignment towards a value between 32 and 35dB Lamax for ground borne noise lead by the USA from 1995.

I am starting to wonder whether we should ask for a 32dB Lamax.