As a Nordbygg visitor ans exhibitor, you get a 10% discount when you travel with SJ in 1 class and 2 class to Stockholm. Breakfast is always included in 1 Class travel on departures before 09.00.
The offer is valid for travel April 21-29 and return trip April 21 - May 2. You can of course book your trip right now.
Other benefits of taking the train are that you get a good opportunity to plan your day and meet colleagues in your sector on the train. It is easy to travel from Stockholm Central to Stockholmsmässan in Älvsjö; if you choose SL you can book it directly via SJ; choose Älvsjö as the destination instead of Stockholm Central.
If you you booked tickets - here you can find more information SJ Info Corona virus »