Capacity confirmation letters in a utilities assessment

Utilities capacity confirmation is the part of the evidence base that costs almost nothing to obtain and derails more programmes than any survey. Five letters, raised at the point you acquire an interest in the site, will tell you whether the electricity network can take your load, whether the sewer can take your flows, and whether there is a 33 kV cable running diagonally across the middle of your layout.

Raise them before the masterplan is fixed. An operator's response is information, and information arriving after a design has been approved by a client is just an expensive problem.

What the assessment is for

A Utilities Assessment answers three questions for a decision maker and one for you.

For the authority: can the site be served, are any offsite works needed that themselves require consent, and does existing apparatus constrain the developable area. For you: what does connection cost and when can it happen.

Keep those apart in the document. The planning audience needs the constraint and deliverability answer. The commercial audience needs the cost and programme answer. A single chapter trying to serve both ends up serving neither, and the usual casualty is the diversion that nobody priced.

Enquiries to each network operator

Write to five parties, and ask each for the same three things: asset plans for the site and a defined radius, a capacity position for your stated demand, and indicative timescales.

• Electricity: the distribution network operator for the area. Give a maximum demand in kVA or kW, the number of units by type, and whether heat pumps and electric vehicle charging are included. Ask for a point of connection and a budget estimate.
• Gas: the gas transporter. Give the peak load and say whether gas is required at all, because an all-electric scheme still needs the asset plan for diversions.
• Water and sewerage: the undertaker's developer services team. Give peak and average water demand, foul flow in litres per second, and the proposed surface water discharge point and rate.
• Telecoms: the incumbent network provider, plus any alternative provider active in the area.
• Third party apparatus: any high pressure gas, fuel pipeline, transmission line or private network shown on the plans you receive.

Demand figures are the input that determines the quality of the answer. Give a stated basis and say what it assumes about electric heating, because a response calculated on gas heating for a scheme that will be all-electric is worthless. That number should come from the same place as the Energy Statement assumptions, and the two documents must agree.

Reading a capacity and budget estimate response

A typical response has five components, and the useful information is rarely in the headline cost.

The point of connection, which tells you where offsite works start and therefore whether they cross third party land or highway. The available capacity at that point. The reinforcement required, if any, described by voltage tier or pressure tier. The indicative cost, split between sole use assets and reinforcement. And the assumptions and validity period.

Read the assumptions first. A budget estimate is not an offer. It is a response to the numbers you gave, on the network as recorded on the day, valid for a stated period, and subject to a detailed design that has not happened.

Capacity is allocated on a first come basis by most operators, so a response confirming capacity today is not a reservation. Where the margin is thin, ask what a formal application would secure and at what cost.

Diversions of existing apparatus across the site

Diversions are the single biggest source of unpriced risk in a utilities chapter.

Start with the asset plans and overlay them on the layout at the same scale. Anything crossing a proposed building footprint, a road alignment or an attenuation basin needs a decision: divert it, build over it where the operator permits, or move the development.

The legal routes exist. The Water Industry Act 1991 provides a mechanism for requiring alteration of a pipe in defined circumstances, and the Electricity Act 1989 provides for removal or alteration of electric lines. Both put the cost on the developer and both take months, because they involve survey, design, land agreements and often street works.

Public sewers are their own topic. Building over or close to a public sewer needs the undertaker's agreement, and the terms depend on depth, diameter and construction. Where the sewer is deep and the building is heavy, the answer may be no. Resolve that before the foul strategy in the Foul Sewage Assessment is written, not after.

Reinforcement lead times and programme risk

Ask every operator for indicative timescales in writing, and record the reply verbatim in the assessment.

Two things drive them. The tier of reinforcement, because works at a higher voltage or pressure involve longer design and approval chains than a local connection. And the highway, because works in the public highway are governed by the street works regime, need permits and are subject to noticing periods and seasonal restrictions on some roads.

Then build the programme backwards from the date you need power on site, not forwards from the date you expect to submit. On a scheme with a temporary builder's supply, a permanent connection needed at first occupation and a substation to be adopted, there are three separate dates and each has its own lead time.

As an illustrative example, a 90 unit all-electric scheme with a stated maximum demand that pushes the local network past its firm capacity, requiring a new substation and an upstream reinforcement, is a programme problem rather than a cost problem. The cost lands on the land value. The reinforcement date lands on the sales programme.

Easements and wayleaves

Every new asset that will be adopted and every retained asset crossing your land needs a land agreement, and these are the documents that arrive late.

Adopted substations and cable routes typically need a deed of easement or a lease, with access rights and restrictions on what can be built over the route. Overhead lines crossing land are usually held under a wayleave, which can be terminable, or under a permanent easement.

Three practical points. The restriction strip either side of a retained route removes developable area, so plot it. The operator's standard form will restrict planting and levels, which affects the landscape scheme. And where a route crosses land you do not own, you need that owner's agreement, which is a separate negotiation with its own timetable.

Presenting the correspondence as an appendix

The assessment's credibility rests on the appendix, so build it properly.

1. A schedule listing every enquiry: operator, date sent, reference, date of reply, and a one line summary of the outcome.
2. The enquiry letters themselves, showing exactly what demand figures were given.
3. The responses in full, including assumptions and validity dates.
4. The asset plans, at a stated scale, with the site boundary overlaid.
5. A constraints plan showing apparatus, restriction strips and proposed diversions.

Number the appendices and refer to them from the text by number. Remove individual staff names and direct contact details from anything that will be published on a planning register, and keep the reference numbers instead.

Where surface water discharge is part of the picture, the same correspondence usually supports the Drainage Strategy, and the two documents should quote the same discharge rate and the same consent position. And where a response has expired before determination, re-raise it rather than leaving an out of date letter in the bundle for an objector to find.

Enter your postcode on PlanScope to see which reports your scheme is likely to need alongside the utilities work.

This is general guidance, not legal advice. Check the position with your local planning authority or a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.