Presume buying your own timber is cheaper than readymade panels…? Any tips as to where to buy?

I want offset or spaced out vertical timbers to let some light in, for the sake of the garden, but give some sense of enclosure. Thinking of concrete posts with horizontal timbers slotted in, and then the verticals simply nailed on.

Gravel boards might be your friend on an uneven site. Presumably you don’t get roadside litter much?

No litter, no. Cul-de-sac.

Cheaper to do it yourself if you want a decent job.

I bought mine from a local timber yard. Did me a better price for cash. 75m boundary length of post + rail + 3ft pickets was about £300 in materials, plus postcrete and a 2-3 days to fit

Wow jam Bo that is cheap. We want 6ft high but only about 10m, 4 posts and two gate posts..

Any builder’s merchants, I would have thought. The sort of thing you’ve sketched is something like I was going to have, but I ended up with feather-boarding in the end, I’d suggest you allow for a strip of weatherboarding along the bottom, about 4-6″, to prevent the bottom of the vertical palings from rotting, each board would be easier to replace than a long length of verticals. The gap between each vertical should be the width of each vertical, so there’s only a slight gap visible at an angle, the beauty is that in strong winds the gaps allow a bit of air movement, easing strain on the fencing. Not so much an issue with mine, and the featherboard was cheaper and easier, although I did get a mate to do most of the work, I’m totally inept at that sort of stuff; I just helped dig the post holes, hard enough in the brash soil around here, where it’s just like dry-stone walling a foot down.

The gap between each vertical should be the width of each vertical

That’s a “hit and miss” style fence:

e.g.: https://www.jacksons-fencing.co.uk/fencing/fencing-panels/hit-and-miss-vertical/fencing-panels-hit-miss-vertical.aspx

Budget a bit for the tools if you’re going to DIY. 2 bags of postcrete per hole, post hole spade and digger. Something heavy to ram down soil and rubble around the posts before using the postcrete.

Typical professional costs are around £50 per metre all in. They’d probably allow 2x half day visits. More for gates.

DIY you could do this around:
4 posts – £20. Postcrete £30. Horizontal timbers £25. Verticals £80. Plus screws.

Either way you’d then have to add money for painting.

The gap between each vertical should be the width of each vertical, so there’s only a slight gap visible at an angle,

I might go for a little more gap than that because I could do with more light on that side of the garden.