Have you tried something like:

GRANT ALL PRIVILEGES ON ALL TABLES IN SCHEMA individual_schema1 TO PUBLIC; GRANT ALL PRIVILEGES ON ALL TABLES IN SCHEMA individual_schema2 TO PUBLIC; GRANT ALL PRIVILEGES ON ALL TABLES IN SCHEMA individual_schema3 TO PUBLIC; ... GRANT SELECT ON ALL TABLES IN SCHEMA core_schema TO PUBLIC; 

This will give R/O access to the core schema to all users (current and future) and R/W on all other schemas.

Alternatively you can grant all this rights to a group (basic_group) and then do

GRANT basic_group to newly_created_user; 

Also you may need to setup the default privileges on schemas, as described in this question http://stackoverflow.com/questions/10352695/grant-all-on-a-specific-schema-in-the-db-to-a-group-role-in-postgresql

Have you tried something like:

GRANT ALL PRIVILEGES ON ALL TABLES IN SCHEMA individual_schema1 TO PUBLIC; GRANT ALL PRIVILEGES ON ALL TABLES IN SCHEMA individual_schema2 TO PUBLIC; GRANT ALL PRIVILEGES ON ALL TABLES IN SCHEMA individual_schema3 TO PUBLIC; ... GRANT SELECT ON ALL TABLES IN SCHEMA core_schema TO PUBLIC; 

This will give R/O access to the core schema to all users (current and future) and R/W on all other schemas.

Alternatively you can grant all this rights to a group (basic_group) and then do

GRANT basic_group to newly_created_user; 

Also you may need to setup the default privileges on schemas, as described in this question https://stackoverflow.com/questions/10352695/grant-all-on-a-specific-schema-in-the-db-to-a-group-role-in-postgresql