Hello, my name is ***** ***** it is my pleasure to assist you with your question today.
Has he been building this during his normal duties for you whilst in employment?
Yes and some in his own time, without me asking him too, he just seems to keep working on it at home
This is an issue of copyright and will be governed by common law and the Copyright and Rights in Databases Regulations 1997, which gives an employer automatic ownership of copyright in works created by its employees in certain circumstances.
There are two questions relevant in these situations - Is the author in fact an employee (rather than a contractor)? If so, was the work created in the course of employment?
If the person is an employee and not a self employed contractor, in order to benefit from the statutory ownership provisions the employer must show that the work was created "in the course of their employment". Inevitably, the wording of an employment contract, and, in particular, any job description will be relevant to define the scope of the employment.
Let’s use an example – if a cashier was drawing in times of low workload, or composing musing, they will own the copyright as this was not done in the course of their employment. However, something in your situation where they are clearly doing the work as part of their employment will likely give you rights over it.
To be certain you may wish to include a clause in their contract to confirm that any works created in the course of their employment will remain with you.
as an apprentice he would still be an employee. However there is no specific need for this to be detailed in his contract - it would help if it was, but if he is required to do that as part of his duties and has done so for some time it would most likely be implied in the contract anyway