The expansion is definitely happening, the school confirmed recently. They are hoping to add the extra class for the Sept 21 intake but that isn't definite yet.
Ah yes the lottery...
There are multiple threads on here about how the equal preference system for admissions works, but in essence you will be offered a place at the school you have ranked highest on the eAdmissions form and for which you (your DC!) qualifies.
So in this instance, let's suppose you live in the catchment for Archer and are likely to get a place, but prefer JCoSS. The important thing is to put the schools down in your genuine order of preference. So in this case you rank them:
- JCoSS, 2. Archer, 3. Fortismere (to pluck a nearby school out of thin air!)
Scenario a: you don't get the lottery place at JCoSS but are allocated Archer; you also qualify for Fortismere but as you placed Archer higher on your application form, you aren't given that place or put on the waiting list there. As you put JCoSS first, you should automatically be put on their waiting list (but it's always worth making sure by speaking to Barnet admissions). You then may or may not get a place at JCoSS from the waiting list as things move around between March (offer day) and September.
Scenario B: you get a place in the JCoSS lottery. Even though you also qualified for Archer, you are not offered a place there because you got your first choice school.
Does that help? The golden rules are 1. to put the schools down on the form in your real order of preference and 2. to put down a school somewhere amongst your 6 choices at which your child will definitely be offered a place. You can stay on the waiting lists for any and all schools you have put higher on your form (or indeed ask to be added to any other list you like) after offer day.