Navigating the pitfalls

Good day all; This is my first post in the forums, my name is as above ( i hope, i won’t know until i see it i guess)…please bear with the following, i will have numerous Q’s, but not all in one post :slight_smile:
I have been looking into the possibilities of buying in Northern - Western France - Normandy /Pays de la Loire areas - That is really a logistical reason of transport back to/from UK…

The question this time is regarding fosse septic…
Before buying a property, i need to know what i am getting myself into, if i buy property that is off mains drainage.
I have seen various threads, ( which has given me good indications of things to look for), but those that i find are a bit out of date.

What i need to know really are : what are my options for systems … and if anyone has links ( or names) I can have a look myself without being a burden.

I also understand some of them can be quite costly - so factor it in to how much to pay for a property, depending on what type of property you buy…ie total renovation, to partly done with a “working system”…

I have also read stories on here that point to drainage installs that reading between the lines have been installed by Cowboys…unless the “rules”/regs are not stringent enough… in this example, house pipework with no U bend traps from showers/sinks etc… but i guess that’s another topic :smile: :smile:

many thanks


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The average cost of a fosse is about 8-10k euros so factor that in with any offer.

Any house being sold that is not connected to mains sewage has to have a diagnostic undertaken:

If the diagnostic reports that there is no Fosse, or the one that does exist is not in spec you will have 1 year after the purchase of the property to build one or make the existing one conform.

In France, renovation can cost anything between 1500 € - 3000 € per sq metre. So for a 150 sq metre house account for anywhere between 225 K - 450 k Euros. Doing some work yourself will bring the cost down but major work should done with a qualified artisan.

Thanks for the info Mark, and had a look at the link… some more burrowing needed.

I’ll do a search for Micro Station, as i wondered if these were widely allowed now or not, as they seem to be “tidier”, and easier / cheaper to install maintain.

I can’t offer any advise on construction of a Fosse.

Controversial as this may sound to those here, for many reasons my rule number 1 when buying a house in France is to make sure it is connected to mains sewage.

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Very few houses outside largish towns are connected to mains drains and consequently the subject of fosses turns up very frequently. Whenever a house is sold the nature and condition of its drainage system is inspected and reported upon. If a buyer isn’t happy with the report he has two choices, either walk away or use the fosse as a bargaining tool. If he chooses the latter and subsequently buys the property he will be given a time span to complete any upgrade needed. At that point I believe SPANC will become involved and after having a survey including a soil analysis the options will be listed. They may include a micro station but anything that relies on electric pumps is not recommended for a maison secondaire. Exactly what the specification required is and consequently the cost varies almost from property to property so generalisations are almost impossible. I can’t understand why a micro station would be ever be considered easier as the word micro is confusing, they are rarely that, and nothing could be simpler than a well installed fosse toutes eaux.

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Blow me down - I just spat some :wine_glass: across the terrace! :slight_smile:

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What a waste :grin:

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You know what Mark? I’m on the cusp - I don’t know whether to invite you over for a long lunch or call 112!

Thank you all for the inputs…besides wasting wine ( obviously a tasting session )…

I have maybe found a solution or two, of products that have been used ( not MS’s with electrics)…

regarding the buying of property either on mains drainage - or not… i guess that depends if you can get what you want within the confines of areas that have mains drainage. If you cant, then has to be as a calculated reasoning as you can make it.


The cost of a standard 3000l fosse with a filter bed is around 5-6k at most not 8-10k. As for renovation costs of 1500-3000 Euros per sqm, that would not make any project viable.

Hi Tim

I think you will find if you google about and read the French renovation sites and also read the renovation type magazines in France that 1500-3000 euros is an accepted guesstimate for renovation. If I were to do another renovation that is how I would price up a property.

In terms of project viability, well I suspect a lot of people have learnt the hard way that renovation is not viable unless it is your dream or hobby.

Also, a fosse guesstimate on French websites is around the 7K mark…but that depends on so many different factors.

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Perhaps it involves Batiments de France?

Having done two renovations for myself and overseen another ten for other people I tend not to rely on Google to work out the viability or cost of a project, obviously I’ve doing things wrong.


i think people can argue until they’re blue in the face on costs… but it is obviously subjective on what the required works entail, from a 150 sq mtr shell with no roof, bad wall, no sanitation… unless it had a gold mine within its boundaries, why would anyone pay 3k euros per sq mtr to have it done ?? doesn’t make sense.

Now turn that around for some quotes for a sanitation system, kitchen / bath, some decorating, window replacements for 30k euros total… for 100 sq mtr house is 300 p sq mtr is viable ( depending on purchase price)…
if someone quoted me 1500 euros per sq mtr ( total 150 k) to do the above, i would ask which banana boat did he think i came over on :smile:

1500€ seems bloody expensive - even more than new build prices in expensive parts of the country according to this list Building Construction Costs in France 2014 | I’d want gold taps for that :slight_smile:

It depends on where you start from (a shell which needs water, leccy and a fosse is obviously going to be more than somewhere with services but in need of a refresh) but our 150m² place had had about 50k€ spent by the previous owner which covered new roof, heating, bathroom, UPVC double glazing, exterior painting and interior decoration. We’ve added a kitchen and repainted maybe 60% of the interior (the quality of the work he had done was good but the colours, oh my the colours) and will not have spent more than an additional 10k€

Yes Paul, as regards the “renovate” / “refresh” - to be fair, what i intend to do would possibly be seen as a refresh.
I am looking at all sorts of properties…but a main priority is somewhere livable, and to the greater good, structurally sound ( not minding some small roof repair or damp proofing). The kind of things ( or combinations of), what i will take on, new fosse, re-plumb and rewire, windows, external render, internal plaster, kitchen / bathroom, general decorating… a lot of the last bits i would do myself; so you could see where the major costs would be.
Probably looking at a max 3 bed…even if it has space to internally fit out for more beds would leave it, as there would then be additional taxes…but if putting in a new fosse, may go larger than required for future proofing.
Lots of things to think of…

But yes, i have seen the decors and colours of property…Oh my word :open_mouth: