Uckfield Electric Forecourt
UKPN Substation

This site is an electric vehicle forecourt. Forecourts historically used coal tar in their surfacing (banned in the late 1980s but still present in older builds) plus decades of polycyclic aromatic hydrocarbons from petrol and diesel spillage. We have assumed half of the 85 tonnes of spoil we excavate is hazardous, which roughly doubles the disposal rate from £20 per tonne (inert) to £100 per tonne (hazardous). If no contamination is found, this £3,400 falls to AIM-ECO margin. If contamination exceeds half the spoil volume, the excess is a variation — we do not carry unlimited hazardous-waste risk.

The cable pit is over 2 metres deep, which classifies it as a confined space under HSE definitions. The law requires a permit-to-work system, a continuous gas monitor (hired at about £40 per day), a 'top man' on the surface keeping watch on anyone working in the pit, and a rescue tripod kit. We have carried 5 days of these provisions to cover the cable pit construction phase.

The substation sits next to a live EV charging forecourt that customers continue to use throughout the 9-week programme. The site cannot be closed. AIM-ECO carries a banksman at the compound entry whenever vehicles or pedestrians could be near the work zone, plus safety barriers segregating the construction area from customer flow. This is not a Traffic Regulation Order — it is the day-to-day cost of working safely on a live operational site.

The 42 working-day programme is tight. We have carried 5 days of standing time for our 3-crew at £800 per day to absorb the kind of slips that happen on multi-trade jobs — late RFI answers, weather days, sub interface issues, the building shell arriving 24 hours late. If we do not use it, it falls to margin.

The internal LV electrical works are priced to the most likely substation specification: BS 5839 Category L4 fire alarm, BS EN 50131 Grade 2 intruder, BS EN 12464-1 200 lux lighting, anti-condensation heating only. If the client confirms a higher specification — Category L3 fire alarm (double the detectors and cabling), comfort heating instead of anti-condensation, or Grade 3 intruder — this £3,500 absorbs the uplift without a variation. If the base specification is confirmed, it falls to margin.

The programme could straddle October through February. Concrete pours below 5°C need frost protection (insulated blankets, accelerator additives, longer cures). We have also carried 2 lost weather days for the open-site civils phase. If the programme lands fully in spring or summer, this £3,000 falls to margin.

Reinforced concrete, structural steel rebar, copper earth tape and HV cable copper are all moving in 2026. With 8 to 9 months between quoting and handover, a 3% escalation on the £50,000 of direct materials covers price drift between today's sub quotes and the day we actually order. Standard practice on long-lead infrastructure jobs.

The base allowance assumes the main contractor's welfare and storage compound is available to us (RFI-005). If they come back saying they do not have one or will not share it, this £1,500 covers a serviced welfare unit hire plus secure storage container for our 9-week site presence.

UKPN substations require evidence of concrete strength compliance — 6 sets of cube tests at an accredited testing house at about £150 per set — plus independent witness inspection of the steel frame erection. The £1,000 covers the testing house fees plus inspector attendance. (Reduced from the v9 allowance, which included HV witness inspection; that scope has moved to the client.)

At handover AIM-ECO issues a multi-trade O&M manual covering civils, building shell and LV electrical, plus as-built mark-ups of every drawing where the build differed from the issue, plus the full certificate pack (EICR, BS 5839 commissioning, BS EN 50131 commissioning, fire alarm test sheets, concrete cube results, HDB torque records). This is more document time than a single-discipline civils job — £1,500 reflects the actual hours.

Our crew has to sit through the UKPN site induction (half a day, cannot be skipped) plus the main contractor's site induction (half a day) plus produce CSCS records for every person on site plus attend the F10 administration the main PC runs. £1,250 covers labour time plus admin overhead for the 5-crew across the 9-week mobilisation.

Our default Professional Indemnity insurance sits at £5 million. Some DNO contracts demand £10 million on multi-trade work — half this line covers the insurance uplift. The other half covers a performance bond if one is requested at award (typically 1 to 2% of contract value per year). If both are confirmed unnecessary at contract negotiation, the £1,500 falls to margin.

AIM-ECO's civils and LV electrical works dovetail directly with the client's appointed HV team. Their cable pulling needs our duct stubs accessible at the right moment. Their termination work needs our building shell handover and external earthing point ready. We have carried £1,500 to cover the programme coordination, fortnightly progress meetings, and on-site liaison hours. If the client's HV team runs to programme, this falls to margin.