Just go compare their Kingdom Halls with those of the 7th day Adventists or Mormons.
In Scotland there are roughly:
35 Mormon Churches
10 SDA churches
82 Kingdom Halls and 1 Assembly Hall
Mormon churches are bigger than Kingdom Halls but are generally empty on Sunday. The one in Johnstone is literally empty, and presumably will be sold at some point. The one in the west end of Glasgow is the biggest in Scotland and used to have two congregations, now only one since Springboig Congregation was dissolved. I think it’s also used as a base for training missionaries.
SDA churches comprise a variety of different buildings. The one in Irvine is an extension of a shop front. The one in Faifley is like a large hut, which is smaller than most Kingdom Halls. The church in Dundee is a large building and they recently built an extension that almost doubled its size. The church in Glasgow is about the same size as a Kingdom Hall and struggles to accommodate more than 120 on a Saturday, which is sometimes the attendance. In Edinburgh they use a large old converted church, which is cold in the winter because they can’t afford heating. In Paisley they rent a hall in a local community centre. The SDA church in Crieff is probably their nicest church in Scotland it has lots of wood beams and windows and large rooms and gardens. Here is a picture.
http://sm.adventist.org.uk/news/archives/sc/scottish-evangelism-training-creating-a-church-for-others
Within a UK context Mormons are overreprested in Scotland whereas JWs and SDAs are underrepresented.