In year school admissions & appealing due to a SEN sibling

[Annabel111]

I have two children, one is 5 and the other is 3. My 3 year old will be going to a special needs school in September 2021.

In September, we will be moving to Hertfordshire. For my 5 year old, the closest school is full for the September year 1 intake. If he goes to a school further away it will be more challenging for us to take him to school and do the school pick up as we need to wait for the school transport to take my 3 year old to his special needs school. It's also more challenging should my youngest need to go to hospital on short notice.

I was wondering if anyone has any advice on whether we can appeal for a place in our nearest school because of our situation?

You want one of the admissions experts really :) but ..

Would it be an infants class size appeal (i.e. there is 30 or a multiple of 30 in your 5 year old's year group)? These are harder to win and transport issues would not normally be taken into account.

If it's not, you might have a better chance at appeal as you can argue on balance of prejudice (to you in not getting a place versus school in taking an extra child).

How far is the allocated school? You may be eligible for school transport.

You can appeal for any reason. As your younger son is going to a special school you do not have the reason that you need both pupils in the same school. The general rule is that it is for parents to get their child to school. Given your principal reasoning will be that you need the nearer school because of getting him to school in time, I think that will not be considered a strong case.
The other major issue is that your elder child is 5 and so any appeal is likely to be an infant class size appeal and the only way that you can successfully win that appeal is for a mistake to have been made. That is very unlikely in the circumstances.
You need to ensure that you do have a school place for SEptember and also ensure that you are on the waiting list for your preferred school. I would also ask the LA about the possibility of the timing of the transport for your younger son being altered so that it fits better to getting your elder son to the offered school on time. If I was in the panel that would be my first question and I might then have a bit more sympathy if there was documentary proof that the LA had said No to your request.
I am not saying do not appeal you just need to be aware that it will be difficult.