Having at least one toilet in your place of worship increases the potential for welcoming visitors and the wider community into the building, as well as being a useful facility for worshippers.

Any new toilet should be designed with access for people with disabilities in mind.  This factsheet sets out the key considerations and gives dimensions for wheelchair accessible toilets.

You may find it easier to raise funds for toilet facilities if you intend widening the use of the building at the same time.  If the toilet is important to enable the proposed activities to take place you may be able to secure some funding through a grant towards those activities.

Providing toilet facilities is more challenging for buildings which lack mains drainage or even mains water.  This advice from Churchcare is relevant here.

This paper, originally commissioned by Gloucester CofE Diocese, provides detailed advice if you are unable to connect to mains drainage.