Regarding the Huay Kon (Nan) crossing, Auke showed some pix from 2011 where the old building was demolished and temporary ones put in place. The old building looks identical to the one at Phu Doo, which I assume will also eventually be converted into something new (on the Lao side the Phu Doo crossing has new buildings). Going through Huay Kon in 2015 I saw the temporary ones. I am assuming they are planning on constructing a new customs/immigration complex on the Thai side as well as on the Lao side. When are these likely to be finished?
New buildings at the Huay Khon crossing - There is a new Immigration building as well as a new customs building (a bit west of the Immigration building) at the Thai side but these apparently are being used by the administrative staff. I think that the main problem is the location and layout of the roads at the border crossing. Around 2011 there were drawings of the new border crossing buildings to be built on the Lao side of the crossing but since that time almost nothing has happened with regard to the Immigration/Customs building at the Lao side.
The new Immigration building at the junction of the road to the village (Chalem Prakiat) and the shortcut to road 101