Certification Bodies for Compost Toilets

Navigating the the maze of local building control, planning permission and building regulations in relation to installing a compost toilet can be intimidating. What doesn’t help is that different regions may have different regulations (or different interpretations of regulations).

In the UK, each country/region (England, Wales, Scotland and Northern Ireland) has its own take on building regulations etc. So England and Wales uses a set of regulations that was changed back in 2010 and for the first time, officially permitted the use of composting and chemical toilets in dwellings (as part of a set of measures designed to reduce domestic water consumption).

Whilst building regulations deal with the toilet (and it’s location and general safety), the composting aspect (and the urine or leachate discharge) would then come under the EA (Environment Agency) or SEPA (Scottish Environmental Protection Agency), although providing the volumes of matter produced are ‘domestic’, you are unlikely to need to apply for a permit unless there is some other mitigating factors such as poor drainage, or flooding danger.

In Scotland, building control documents say; “Waterless closets must follow the guidance in this clause and should be certified under Standard NSF 41 or NSF/ANSI 41 or by a notified body e.g. BBA.”, although they then indicate that there many European made compost toilets not made to a specific standard, and imply that you can use them if you can be sure of their safety etc.

https://www.nsf.org/consumer-resources/articles/composting-toilets

The problem with the NSF41 standard is that it applies to compostING toilets – in other words a system where the ‘raw’ material goes in and compost comes out, and I have to conclude that the Scottish standards were probably drawn up many years ago, before ‘modern’ compost toilets were easily available in the UK. Most compost toilets (note the lack of ING on the end) are actually just collection units where the final composting is done away from the toilet. This makes the toilet much simpler and less reliant on power and gears and mechanical stuff (which can easily break). Arguably, most composting toilets (certainly the small units for houses) don’t actually produce compost – at best, they desiccate the solids using airflow, sometimes heat and agitation, but as composting is a long-term biological process, the contents will need further processing before they can be safely used as a growing medium.

The further problem you might encounter is ignorance or a lack of awareness of modern compost toilets and how they work. It’s understandable given the workload many local authority officers are now given – it’s easier for them to refuse at the first hurdle because they don’t have the time to research things.

For new buildings, particularly where planning permission is sought, the issue of the toilet can be a stumbling block, although it does depend on the individuals involved – some people get approval without any issues.

Where the toilet is going in a shed or glamping unit, i.e. no planning permissions are sought, then many people just get on and do it.

Around the world

Each country will have a different approach. France is now more open to compost toilets compared to it’s official position ten years ago. And in the USA you have individual state regulations etc so whilst it is legal to have a compost toilet in Oregon, you are not allowed to compost the contents (or at least that was the position – let me know if it’s changed now!).

It’s easier if you can stay under the radar, but it’s not always possible. My hope is that in time, more governments and local authorities will accept the benefits of compost toilets and adopt a more pro-active and helpful approach to those people who want to install and use them.


If you’re from outside the UK, what regulations are applicable to you? Did you manage to get around them? Let us know!

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