saveasteading

If you have the luxuries of space and time, then working with an open trench, or part, removes these risks entirely.

I've seen cables sticking in ducts, resisting the winch tension.... scary. Had to dig another draw point. You must not have any wobbles in the duct. None, zero.

Great advice above. There is some territory defence instinct in us all. Try to rise above it. As insurance, and I think some comfort, i would recommend keeping a diary. Just a blank hard-backed book and only use it when there is something to record. Mundane or passionate as appropriate.Eventually this will also become your site diary. Being blank allows you to make no entry or write a paragraph or whatever. A gap in dates in itself shows that nothing was worth recording in your opinion. Such a record can be amazingly powerful in any future formal argument. Allows you to relax and not carry this mental load at all times.

Or that part of France or what the Mayor thinks. I've been involved once and it was surprisingly informal in a good way. Local contacts helped. Discuss with the selling agency...they might have into or contacts. I was going to say that you always have Saniflo as the worst case, but not if M. le Maire ne ce l'aimez pas. Rearrange words as necessary.

Road partial closure, if that applies, is the worst case for cost. Full closure is much cheaper. That sounds like a safe estimate. I too have often had fruitful discussions , usually requiring homework....with which BH can help: as previous messages... tell us more. Best not disclose who the quotation is from. If it is a quotation rather than estimate then they have to be on the safe side, because they get so many requests, but will then usually engage with more info.

What ground do you have? A 2 to 3 tonner can struggle or be totally ineffective with, for examples, heavy clay, chalk, dense gravel.

Agreed and very easy to resolve. I suggest a plastic chamder and cover, so you can easily get an arm in and to the bottom. Also the possible benefit of allowing rodding in both directions. Depending what's in it, this could be in manhole style with a profiled base, or as a catchpit. Apologies that I have not read back. If there is any reason that you cannot have a chamber there, then you could possibly fiddle that through using pairs of 45° bends or less, or adjustable bends. But there must be a constant fall. If you include a rodding unit then it could all be in 6 or more parts. This gives you a bit more wiggle (adjustment) too.

The only problem I can recall in many km of drains is with connectors from one supplier. They were a pain to fit, but they then worked and it saved a lot of money. My default is to use a smaller merchant and likely a brand that is not major, but the quality is good.

The tiles under the units are the easy ones anyway.

My admirable small grounworker contractors over the years are my guide. They tended to have a middle aged tracked kubota or similar. They break down or lose tracks regularly, and often the repair cost is unviable... then they get abandoned until given away. Owning one has the advantage of instant availability, and saving time, hire cost and transport. Owning on one's own plot removes the HSE overview on commercial sites, and transport. BUT. Breakdowns as above. It very often isn't the right machine...too small, needs tracks, not performing. I suggest a long chat with the managers at local hire companies. The smaller ones especially. They might have a machine nearing selling on stage which could sit with you instead of in their yard. Pay by the clock plus a monthly. They maintain. You also agree a discount on other hire equipment but promise (and keep to it) not to hire from elsewhere. OR they sell you it but provide some guarantee, at least on major issues. They might say no but have another suggestion. They will probably like you, the project, the enthusiasm, and the 2 years of hire coming. I'd enjoy sitting with you in that chat. £5k mentioned above, plus maintenance? How far will that go in hire cost?

They meaning Oso ? For clarity.

To be completely fair I should have added that some consultants, real Professionals capital P, relish information and ideas and practical input on construction and cost from clients and contractors. I recall multidisciplinary design-and-build projects where we effectively won a project in that meeting. Architect, Civil Engineer, QS, electrician, plumber and contractor (design managers and construction manager). What a great buzz and commitment from all parties.... Great for Client value too, but the other 3 contractors were wasting their time for the next few weeks to tender. Sorry, wandering off there... Teamwork and enthusiasm, and the ruthlessness to dismiss non team-players is my point. BH offers some of this.

Seriously, that was a very useful discipline in teaching the power of ten and having an understanding of numbers being big or small. Also in significant figures when using one of these new calculator thingies.

My pitch on this. How much Risk and hands-on? If you project manage and don't have a main contractor, and do some of the work, then it is self build. The degree varies from there of course. 100% means no contractor, but help from friends and family. Next level includes labourers or semi skilled workers ... . But it's all your responsibility. From there down to 10%. A nonsense figure of course. Several trades contractors, some diy. We will all have our own views on this according to skills and experience.

Bravo. Good plan. Some 'experts' ( mostly in these recently created specialities) are lacking but must have known how to pass the exam. Others are technically good but don't consider options or cost. I hate it most when they write in a supervisory role for themselves. Mostly I have encountered these at planning stage. Some I submitted very detailed counter-arguments and succeeded. Archaeology; planting; newts; Breeam; come to mind. On one of those I even achieved a certificate without much study. The experts back down if the argument is strong.