Who prepares a utilities assessment
A utilities assessment is written by an engineer but built from capacity responses only the network operators can give. Running those enquiries late is what wrecks programmes.
No statute names an author for a utilities assessment. In practice it is assembled by a civil or infrastructure engineer, or by a utilities consultant, from capacity responses that only the asset owners can give. That division matters more than the job title. The engineer writes the document, interprets the constraint and shows how the layout responds, while the actual capacity position comes from each distribution network operator and statutory undertaker in writing.
Which is why a utilities assessment written without those written responses is a desk exercise. It will read convincingly and tell the case officer nothing.
What the assessment has to establish
A Utilities Assessment answers four questions for each service: is there an existing connection point within reach, is there spare capacity at that point, what reinforcement or diversion is needed, and how long will it take. The fourth is the one that changes programmes.
The services usually covered are electricity, gas, potable water, foul drainage, and telecommunications. Surface water is normally dealt with separately in a Drainage Strategy, because the lead local flood authority and the sewerage undertaker apply different tests to it.
Existing apparatus crossing the site belongs in the same document. Easements, build over restrictions and wayleave widths constrain a layout as firmly as a tree root protection area, and they are harder to argue with.
The assessment also has to draw the distinction between a connection and reinforcement. A connection brings a service from an existing point of supply to the site boundary and is largely a cost question. Reinforcement means the network itself cannot carry the load, which is a programme question and sometimes a viability one. Officers read the two very differently when a condition is being drafted.
Who makes the capacity enquiries
Each service has its own route, its own form and its own charging basis.
- Electricity: a budget estimate or point of connection enquiry to the distribution network operator for the area, or to an independent connection provider competing for the work.
- Gas: a capacity enquiry to the gas transporter, which may be the incumbent network or an independent operator.
- Water: a developer services enquiry to the water undertaker, with a requisition under section 41 of the Water Industry Act 1991 where a new main is needed.
- Foul drainage: a pre development enquiry to the sewerage undertaker, with requisition under section 98 and adoption of new sewers under section 104 of the same Act.
- Telecommunications: a new site enquiry to the fixed line network operator, which is usually the least constraining and the most often forgotten.
The enquiries can run in parallel and should. Sequencing them because each one seems to depend on the last is the single most common cause of a utilities programme overrunning a planning determination period.
Who holds the information you cannot get yourself
Asset records come from the owners. A statutory undertaker will supply plans of its apparatus on request, and the responses define the baseline the assessment works from. Where records are old or hand drawn, a site survey using cable and pipe detection equipment is the only reliable way to fix positions before a layout is committed.
Diversions and who designs them
A diversion is a different undertaking from a connection. For water and sewerage, section 185 of the Water Industry Act 1991 gives a landowner the right to require an undertaker to move a pipe, at the landowner's cost, provided the undertaker is satisfied the alteration is reasonably practicable. Electricity and gas diversions run under the relevant industry codes and the asset owner's own standards.
Design is usually carried out by the asset owner or by a contractor accredited to its standards. The developer's engineer specifies what has to move and why, and then has limited influence over how. Working with a diversion in mind at concept stage is nearly always less expensive than designing a layout that forces one.
Overhead electricity lines are the clearest case. Undergrounding a line to free a developable area is a priced service with a long lead time, and the quotation usually lapses after a fixed period. Accepting it too early ties up money, and accepting it too late holds up the build. The useful discipline is to get the quotation during the application period and accept it on the day permission is issued.
An illustrative example
This example is illustrative. A 35 dwelling site on a former depot has an 11kV overhead line crossing the northern third and a public combined sewer running diagonally beneath the proposed access road.
The overhead line diversion is costed by the network operator and takes the best part of a year from acceptance of the quotation. The sewer is the sharper problem: the undertaker will not accept an access road over a combined sewer at that depth without either a diversion or a structural crossing designed to its standard, and the easement width removes two plots from the layout.
Neither issue is a planning objection. Both change the scheme that should have been submitted. Running the enquiries before the layout was fixed would have cost a few weeks at the start rather than a redesign and a section 73 application later.
Lead times and the programme consequence
Published service levels for capacity enquiries, quotations and connection works differ between operators and regions, so the honest answer is to check the current service standards for each undertaker rather than to assume a figure. What can be said with confidence is the shape of the risk.
- Capacity enquiries are quick relative to everything else and should be raised before the planning application.
- Reinforcement of an electricity network is the long pole, because it may depend on work at a substation serving a wider area.
- Requisitions and adoption agreements under sections 98 and 104 involve legal drafting and surety, which run on a legal timetable rather than an engineering one.
- Street works to reach the connection point need a licence or permit from the highway authority, and that process sits outside the utility's own programme.
Where a condition requires utility works before occupation, the agreement and the physical works both have to be delivered. Reading the condition against the real lead times, before the permission is issued, prevents the familiar stand off between a finished house and an unenergised connection.
Reporting it for the planning application
Officers do not want the correspondence. They want the conclusion and the evidence that it is reliable. A usable assessment states the enquiry reference and date for each service, summarises the response, identifies the works needed, and says plainly where a constraint has shaped the layout.
Where capacity is confirmed, say so in one sentence and move on. Where reinforcement is needed, explain the route to delivering it and whether a condition or an obligation is the right mechanism. Where the position is unresolved at submission, say that too, because an officer who finds a gap is better placed than one who finds an unsupported assurance.
Where a scheme relies on a private treatment arrangement because no public sewer is within reach, the assessment has to deal with the first time sewerage provisions and the environmental permitting position, because the sewerage undertaker will say so if the applicant does not.
Foul capacity deserves its own paragraph on any site of scale. A Foul Sewage Assessment that records the undertaker's response on treatment works headroom is the document that stops a late objection from becoming a refusal.
PlanScope drafts a Utilities Assessment structured to the way councils read it, with "TO BE CONFIRMED" flags wherever a capacity response is missing, and the professional directory is there for the engineer who needs to check and sign it off.
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.
Frequently asked questions
Does a utilities assessment need a chartered engineer?
No statute requires one, and councils do not usually name a qualification on their validation lists. What they expect is evidence: dated enquiry references and written responses from each undertaker. A chartered civil engineer adds most value in interpreting reinforcement options and easement constraints rather than in assembling the correspondence itself.
When should I raise capacity enquiries?
Before the layout is fixed, and certainly before the planning application is submitted. Capacity enquiries are inexpensive relative to a redesign, and the answers often move a substation, change an access position or remove plots. Raising them after permission is granted converts a design question into a section 73 application.
Can I build over a public sewer?
Sometimes, with the sewerage undertaker's agreement and a structural design to its standard. The alternative is a diversion, which a landowner can require under section 185 of the Water Industry Act 1991 at their own cost where the undertaker is satisfied it is reasonably practicable. Either route needs settling before the layout is committed.
Who designs a utility diversion?
Normally the asset owner, or a contractor accredited to its standards. The developer's engineer defines what must move and why, but has limited control over the design and none over the asset owner's internal programme. That is why avoiding a diversion at concept stage usually costs less than managing one later.
Is surface water drainage part of the utilities assessment?
Usually not. Surface water is normally covered by a separate drainage strategy because the lead local flood authority applies the SuDS hierarchy and the sewerage undertaker applies its own discharge criteria. Keeping them separate also avoids a single document being held up while one consultee comments.
Sources and further reading
This article is general guidance about the planning system in England and, where stated, the rest of the UK. It is not legal or professional advice. Check your local planning authority’s validation requirements and take professional advice for your specific site.