New to this

Our perc test failed for soakaways, so our planning has insisted on all surface water being piped into a drain with a rumble strip and then on out to the ditch. Aren't we fortunate?!

Thanks @SimonD - I didn't know about the Type 1 vs 3 thing. Is that in the BRegs? My site is quite a decent size and there will be about a third of an acre left after build for water to run off to, if that makes sense, but I've no idea about this stuff and it does concern me I'll run into issues with BC inspections and sign-offs!

Hoping you experienced folk will guide me; how do I research / know what is the 'correct' ground prep for excavating - in this case specifically site access (needs widening considerably as all construction vehicles need to get from single track lane onto site currently entrance <10m wide) and then the 30+m of sub base that will eventually be finished as our new driveway and also the 2m perimeter around the house for scaffolding, and later for pathways? I haven't chosen a final drive surface yet. Two builders have given figures but I can't compare them as one goes down 300mm while the other 400mm (this is to lay geotextile, then hardcore, then Type 1 compacted, in case that makes any difference). I want to spend the 'most minimum' I can on this without compromising quality; it needs to last once driveway is topped with whatever the final finish is, but I don't want to throw money I don't need at it either. Ground is very high plasticity clay, if that makes any difference.

Hoping you experienced folk will guide me; how do I research / know what is the 'correct' ground prep for excavating my access (needs widening - a lot - from single track lane onto site) and putting down the hard standing that will eventually be finished as driveway and also the 2m perimeter around the house for scaffolding, and later for pathways? I haven't chosen a final drive surface yet. Two builders have given figures but I can't compare them as one goes down 300mm while the other 400mm (this is to lay geotextile, then hardcore, then Type 1 compacted, in case that makes any difference). I want to spend the most minimum I can on this; it needs to last once driveway is topped with whatever the final finish is, but I don't want to throw money I don't need at it either. Ground is very high plasticity clay, if that makes any difference.

Really appreciate the input @Nickfromwales, @Russdl and @BotusBuild - we are sticking with ONE BIG DOOR 🎉

@Nickfromwales I think this may help - there's width to add the central pillar, by reducing the two side returns. All the supporting pillars around the permeter will be tied in as they are built. At our previous house, we had the garage in the photo - the pillar isn't massive. Apparently the concern now being expressed within the New To This household is that pretty much the entire width of the garage is exposed to the elements once that single door is opened, I personally don't see it as an issue, but it's Himself's baby, not mine!!!! His precious chariot will live in there, alongside the tractor mower and a few other bits. There's a separate pedestrian door in/out as well. @BotusBuild, I wouldn't put the goal post in if we are going for two single doors, simply the normal lintel over each opening. I should have added images at the start, would have made it a little more evident for all what I was getting at.

Definitely where my head's at - but as a total novice, I don't know if a decision like that 'now' has consequences down the line! Thanks for sharing your view BotusBuild

Hoping you can point me in the right direction - our plans all drawn up by previous architect, approved by local authority planning department and foundations/steel work calcs completed by our SE. We now wish to switch out the planned 4750mm-wide large roller door in favour of two more typical (about 2.4m each) doors. What do I need to organise next for this to all work out ok? Will I need to go back to the SE, to get the steel goal post structure replaced with 'just' appropriate lintels, or can builder simply get on with that? Aside from the planning angle, what other impacts should I be considering here? It's a block single skin structure with double block pillars at appropriate points around the perimeter. I'd now look to block or double block the central supporting 'wall' between the two new openings, and sit the lintels on those. The already-designed structure has double blocks on left and right hand side of original large door anyway. We are likely to have LABC and self build warranty in place, we plan to build this structure first, to provide on site storage / welfare etc while house is built.

Hi Russell, I don't have the drawings for the DAN-wood house just yet; however I have the drawings for the previous timber framed house. That was as I described - made my eyes water!! 1.9m deep closest to hedge on strips 750 wide, graduating back to 1.1 deep on 500 wide, then the B&B with a huge void and finally a reinforced slab. That was for a passivhaus, but I'm not sure I should hope for it to be any different now, and I'm sure the D-W spec on site prep says something like 'do your SE-designed foundations, then cast a slab over the top to this specification' ... my computer's playing up just now, and won't let me access the files I wanted, to share more info.

Full virgin clay, three trial pits from 1-1.5m depth showed only blue/grey with occasional orange tinges of clay under a silty topsoil no more than 200 at most deep. This land was agricultural for a minimum of the last 100 years, as we know the farming family who had it. I need to go and read up on structural slab versus anything else ... our design to date has reinforced strips foundations, topped with blocks and beam, above a void of 300mm, then an insulated slab on top of that. Pricey!

Thanks for replying so very quickly. Our architect did suggest we could remove the hedge completely, but we don't want to (nor can I imagine the Planning Dept being at all happy!)!! And I completely agree with you regarding the risks of neighbours planting whatever they like on boundaries ... oaks and willows seem to be the worst possible tree species especially on clay from the viewpoint of how much they drink from especially clay soils.

@Rosslyn that's so good to hear. I wonder if you have the geo-tech results and would feel able to/happy to share with me? I'm just pondering whether it's an investment for me to get a different SE's take on the design - it's not that I have any reason not to have blind faith in my SE, more that I haven't a clue about the subject, and pondering would a different SE perhaps have a different take on the information. I have a set of lab results from our geo-tech survey that show our ground ranges from the highest category of "High" plasticity, up the middle of the "Very High" range and I believe it's this that is blocking our preference for an insulated raft solution.

@saveasteading the structural engineer said because of the species, they had to be accounted for even though it's a hedge we own / control. It's about 2m wide, as a hedge, and the building is going to be about 7m from the inside edge of it. The specific species are hawthorn, blackthorn and field maple, if that's of any use?!

@Rosslyn just wondered how you got on with your foundation design? We too are getting close to that stage; highest plasticity clay and a hedge the full length of the house with tree species has me a tad worried!!

That's super helpful, thank you very much. They've now said £7K, they will give me my connection. Still staggered at £7K when I'm doing 90% of the trenching - literally - but I don't think I have any choice do I? Who would I even complain to about the DNO quote ... it's a monopoly situation isn't it?

Thank you for this - how can I tell whether it's classed as extension or reinforcement, as clearly it's better for me if it comes under the latter ... should I be asking them to increase supply provision to my existing home here perhaps (as new build is in garden)?

Tearing my hair out; in Jan 24 several months after submitting our application, we were told by our DNO that we could have our new connection and a quote & proposal offered at about £12K for the work. Fast forward a few weeks, we went back to ask them to look again for an alternative route as that first one wouldn't work, too close to the main roots of a 300-400 year old Oak in the boundary line. They've now come back and said they think the first quote was incorrect, that the line won't cope with our new connection and they've referred it up to the detailed or senior design team. This despite my explaining - again - that we are building a passivhaus with a tiny heat load requirement, no ASHP etc etc all the ground I covered with them the first time around. The inference on the phone today is that we could be looking at upwards of £100K to upgrade the line - we're on the lowest power and the transformer is very small currently. I'm heartbroken; not only have we spent several thousands (tens of) since they gave an affordable quote on surveys and fees, but this feels like The Dream going up in smoke. I now have to wait another 4-6 weeks for a decision. I've logged a complaint on the basis two people worked on the quote last year and accepted the load, now one chap has reviewed it and says 'no'. Appreciate there's probably nothing I can do but has anyone got any ideas of what else I could try / who else I could talk to etc please?

Hello, first timer here, hoping to self build a 2 storey upside down house with a balcony along most of two sides of the building, plus a large 4m2 'platform' to one corner. At the stage of architect design, hoping to sign off in the next three weeks on the high level design but anxious about the cost of my huge extravagance. I've tried to work out who to open a conversation with to get some idea of the possible costs and complexities involved. Do I 'just' need a local steel fabricator? I'd like steel posts from ground to first floor level to support it, a steel 'bed' to set the floor into and glass panels all around ... and a stair case to the garden. South Somerset area, if anyone can recommend a contact? Thanks v much

Yes the NSBRC has clay blocks, JUWO is the brand. As others have said, been used on the continent for decades and I’m told over here, many Lidl stores built with these. I haven’t heard of them being used for retaining walls though (I am a simple wanna-be self builder though, so that carries no weight!); if the NSBRC is within your reach, go along and speak with one of their experienced members of staff/owners, they will try to help you.