Hello and thank you for your inquiry.
Your situation is governed by the Residential Tenancies Act 2010:
If you are no longer within the term of a fixed term lease agreement, or never were, then your landlord can terminate your lease at any time, but must give you not less than 90 days notice, as set out in Part 5 of the above Act.
If your husband did major work to the sun room with the landlord's consent and this work has significantly improved the value of the property, then it might be possible to argue that you are entitled to some payment in equity to compensate you, however, if it was done without consent, the landlord can technically require you to reinstate the property to its original state at your own expense.
For more general information about your obligations and rights as a tenant and the process of ending your tenancy, I suggest you review the material at the following link:
I trust the above assists.
Good luck and please rate my answer.