If you need to carry out any work to your church (other than routine maintenance and minor repairs), then you will need permission to do so in the form of a faculty, which applies to all Church of Wales’ churches regardless of whether or not they are listed. Faculty applications are submitted on a faculty form to the Diocesan Advisory Committee (DAC) in each diocese for review. They are then passed onto the Diocesan Chancellor who makes the decision to refuse or grant the faculty. It is strongly recommended that all faculty applications are discussed with the DAC Secretary before submission. The faculty procedure and its rules are part of the Constitution of the Church in Wales. Click on the link below for more information about faculties:
Faculty FAQs Guidance Note

The following topics will also assist you in making a faculty application:

Minor and Emergency Works
Some minor works or maintenance tasks do not require a faculty. However, it is important to be able to identify these works as an accumulation of minor works or small changes to a church can have a significant impact on both its appearance and fabric over time. Always consult your DAC Secretary or Archdeacon for clarification. Also, carrying out emergency works to a church without a faculty is normally only justified when an unforeseen incident has occurred that will seriously affect the security or structural stability of the building, or the safety of people in and around it. For more information please click on the link below to download a guide.
Minor and Emergency Works: Guidance Note

Listed Buildings and Scheduled Ancient Monuments
Many Church in Wales’ churches are listed buildings (LBs) and will therefore require more sympathetic treatment than an unlisted church when considering any works to them. It is therefore advisable to check if your church is listed and view the list description before applying for a faculty. Occasionally, you may also find a scheduled ancient monument (SAM) within the churchyard, such as the remains of a medieval preaching cross. Any works to to a SAM will require scheduled monument consent directly from Cadw in addition to a faculty. You can search for information on LBs or SAMs on the Historic Wales Portal. Alternately, you can speak to your DAC Secretary or Local Authority for LB information, or Cadw for both LB & SAM information. See links below for Cadw and the Historic Wales Portal.
Go to the Historic Wales Portal
Go to the Cadw website for scheduling information

Planning Permission and Building Regulations
Some works to churches (such as an extension or new building) will require planning permission and building regulations approval, in addition to a faculty. These would normally be applied for by your professional advisor (eg. architect). If in doubt speak to your DAC Secretary. Information about planning permission & building regulations can be found on the Planning Portal and the Directgov website. You can also contact your Local Authority.
Go to the Planning Portal
Go to the Directgov website

Statements of Significance & Justification
A Statement of Significance defines what is special about your church. This could be architectural, archaeological, historical or liturgical. It helps you to think about the wider context of your building and its relationship with the surrounding areas and how any proposed changes to it will affect these. A Statement of Justification gives you the opportunity to explain why the work you are seeking permission for should be allowed. It asks you to consider the impact of the work on your building and why it is necessary. It is required for any work that will affect the significance of your church and needs to be submitted at the same time as the faculty application. For information on when these statements are needed and how to write them, click on the link below:
Statements of Significance & Justification: Guidance Note