Friend's Meeting House
Ship Street, Brighton, East Sussex
100% positive
Directions: When you come in the main entrance, the gendered toilets are on your right. There are steps into the main entrance. The corridoor leading to the toilets is sloped with a handrail. The step-free entrance is on the left when you are facing the building. I've not used this door so I can't describe how to get to the accessible unisex toilet from there.
Comments: They ask you to make a small donation after using the loo if you've come in off the street. The lock on the accessible loo is difficult to work.