Doors that are part of the pool barrier must adhere to the The Building Regulations 2012, that all private swimming, spa and portable pools that contain water that is more than 300mm to have a compliant safety barrier installed.
If you already have security doors and screens on your property, they can be changed so they follow these safety regulations. This may include raising the lock height of your existing security door and add a self-closing device which can be done for a third of the cost of a new door.