Mr Punter

Ask him where it says that in the regs or what standard he is working to. BS EN 752 only refers to minimum gradients as do all the warranty providers. The only time steep gradients are an issue is with systems with slotted pipe to allow infiltration to the ground and systems where you need to control the velocity before entering a treatment plant.

It just gets silted up if on clay

Can I be your friend as well please?

But I think the OP wants line, not level.

Depends on the soil type. You don't want the pipe clogging up and I guess the graded thing should stop this. Depends on soil type. In heavy clay, most land drains fail over time because they clog up. I have seen lots of examples of old pipes completely blocked with clay. Regarding fall, as long as the pipe does not get silted up it is fine to lay level if it is sited low enough and has a gravity outfall.

As a more simple but slightly bodged solution, fit a drainage channel in the gap with a downpipe going through upper bit of the wall with the decking on it and dropping down by the bins. Make sure it is set slightly lower (5-10mm) than the driveway paving and seal the paving and channel with decent mastic. If the gap is not wide enough you may need to cut down the paviours or rotate them.

If you had a French drain against the outside of the wall and a route for the water to go it would improve things. You would need to remove the course of charcoal paviours and dig down to the garage floor level. While there you could apply some external tanking. You would need a pipe so that the water could be directed to a drainage point where the bins are? Does it properly flood or is it just the bit of seepage?

Maybe crushed concrete, Leca, EPS? Work out the area and the required finish and see if it would work within your budget.

Plenty of big contractors have their own SEs and will get them to value engineer the design to remove the unnecessary bits. If we have got to the on site stage and something comes up we would approach the engineer with our suggested design and ask if would be acceptable. Normally I try to do this at the design stage, before I have paid their invoice! I recently got some ground floor slab mesh changed from 2 layers of A393 to a single layer of A142. The ground is hard chalk. The site is really restricted and I didn't fancy hefting heavy mesh about that was not required. They also removed at our request a lot of steelwork from an earlier design that would have made demolition / temporary works very awkward. I do agree it is not sensible to just ignore what has been designed.

You could remove the suspended timber floor and install a new fully insulated solid floor.

I only ever see water bar in a basement. I often see SEs wasting client's money on pointless items or impractical details that end up being adjusted or omitted on site.

Please tell me you don't need to go back to planning with the changes?

Absolutely no idea why there is a water bar specified. A complete waste of money and resources.

Can you drive in a stake nice and upright either end then use them as a sight line for the intermediates?

Why not just submit plans to discharge the condition that show the existing driveway being retained as is?

If the chamber is outside it is a matter disconnect mains, open the lid, pull out the pump, which will be attached to a chain or rail, disconnect waste pipe and cable, connect pipe to new pump and cable to mains, drop it back in and switch on mains again. You may like to take a shower after, or at least give your hands a quick rinse, before you go out to dinner with that nubile secretary from accounts.

The 30 year multipanel stuff is ply. Any chance of a target price per m2 column?

If it is normal screed (sharp sand / cement mixed damp), 75mm is the standard thickness.

You may find that external wall insulation will be better in terms of damp, as the wall will be kept much warmer.

The MVHR system is for ventilation only, not heating or cooling. You would need an air conditioning system to achieve this. A 100A single phase supply is fine for most houses. It is very rare that you will be anywhere near this. With car charging, if you want to charge at 22Kw you will need 3 phase.

I would insulate the walls with PIR like Celotex or Kingspan, 60mm thick. Either tape the joins with aluminium foil of cover the lot in polythene. Use 25mm x 50mm battens with 130mm screws and rawlplugs to hold it in place and create a service void. Finish with 15mm plasterboard. For the loft assuming you are having a ceiling you could use loft roll insulation 300mm, making sure there is decent airflow from the eaves.

I got some a few years ago from Vastern Timber. May be worth getting a quote. It is quite splintery so wear gloves.

We specified Sandtoft 20/20 interlocking clay tiles in ‘Antique’ for a forthcoming project. Dark grey / black clay.

Perhaps visit your local builders merchant. Did you work out the cause of the crack?

If the existing frames are OK, secondary glazing can be cost effective. The glass sizes will be bigger than the primary glazing so have a different resonant frequency. If you use a thick acoustic glass, which is laminated with an acoustic PVB interlayer, there will be a marked improvement.