They have their own Building Standards, which are more stringent than England and Wales which can be found at:

http://www.sbsa.gov.uk/

Air Tightness is already a part of current standards, however currently they can (subject to a few proviso's) use a design air tightness of 10m³/m²/hr @ 50 Pa and avoid the requirement for air tightness testing to be undertaken.
From the next reg's change, air tightness testing will be required of a representative sample of each dwelling type being constructed for each development.

Their consultation document for the next regulations change is also currently available for download and consultation responses:

http://www.sbsa.gov.uk/latestupdates/consul_energy09.htm

Sorry to bother you once more. I seem to having problems finding the information I require. The conservation of fuel and power is Part J in Scotland isn't it?

I also cannot find reference to the regs change and consultation responses?

Building standards are changing in Scotland on 1st October 2010. Aiming for 30% reduction in predicted CO2 than 2007 standards. Airtightness testing is to be phased in from May 2011. The target will be 7 m3/ m2h@50Pa.

Regards
Matt

Energy is part 6 in the Scottish Regs.

Its route to zero carbon is based on the Sullivan report:
http://www.scotland.gov.uk/Topics/Built-Environment/Building/Building-standards/about/sullivanreport

The regulations will be changed in steps in Oct 2010, 2013 and 2016. Non domestic is likely to take until 2018 to change. We do not have the code up here, the regs are only interested in carbon emissions. Scotland claims the 2010 regs will be the toughest in Europe, but given there are no standards for airtightness (just targets) it is a little difficult to see how this claim is justified. Also the 2010 regs for non-domestic buildings are watered down from the Sullivan report.

There are rumours of a Scottish Code of sorts but what shape it will be is anyones guess.
Matt