Blog Friday 14th November, Bevan Brittan, Corporate Partner

Holding back the homes: can councils tie occupation to sewage upgrades?

Few areas of planning law generate as much local tension as new housing meeting old infrastructure. Across England and Wales, housing schemes are increasingly colliding with limits on wastewater capacity. Environmental regulators are warning that overloaded sewerage systems and treatment plants are polluting rivers and estuaries, just at a time when local authorities are being asked to deliver record numbers of new homes.

A common device emerging from this clash, and one which is strongly supported by the water companies whose creaking and leaking systems sit at the heart of the problem, is the ‘Grampian condition’ - a planning condition which prevents the occupation of development until such time as the system can handle the additional connections. Water companies cannot refuse to connect a new home to the system once built. Therefore, to protect their systems, their best bet is to encourage the local planning authority to delay those connections for as long as possible.

But can local planning authorities lawfully grant planning permission for new homes, subject to a condition preventing development or occupation until wastewater treatment upgrades are delivered?

The legal framework

The power to impose planning conditions derives from section 70(1)(a) of the Town and Country Planning Act 1990. Conditions must meet the well-established six tests, now reflected in paragraph 56 of the National Planning Policy Framework (NPPF). To be lawful, a condition must be:

1. necessary,

2. relevant to planning,

3. relevant to the development,

4. enforceable,

5. precise; and

6. reasonable in all other respects.

A ‘Grampian-style’ condition, so called after Grampian Regional Council v City of Aberdeen District Council (1984), restricts development until works on land outside the applicant’s control are completed. Such conditions are permissible where there is a reasonable prospect that the off-site works will take place within the period allowed by the permission.

Applying these principles to wastewater infrastructure

In many areas, treatment plants are already operating at or beyond their capacity and water companies are taking a hard line when commenting on applications for more homes in areas where their infrastructure is already struggling.

There is no statutory requirement on local planning authorities to consult water companies on development proposals, although many do so. Even where a water company has been asked to comment on a planning application, the local planning authority is not legally bound to follow their recommendations. The final planning judgment lies with the authority itself.

Granting permission with a condition preventing occupation until upgrades are complete can, in principle, be lawful and appropriate, provided that the condition satisfies the six tests.

If the existing treatment works cannot accommodate new flows without breaching their limits, a condition tying occupation to confirmation of capacity improvements may be the best means to ensure that the development doesn’t result in disastrous environmental consequences. In such cases, the condition may be necessary to make the development acceptable in planning terms.

Reasonableness and the prospects of delivery test

Government guidance (PPG, para 009) supports the use of Grampian conditions, but cautions that such conditions should not be used where there are no prospects of the action in question being performed within the time limit imposed by the permission.

This leaves the question: if the upgrading of the wastewater treatment plant or capacity improvements depend on third-party funding, uncertain regulatory approval, or long-term investment cycles, might the condition be deemed unreasonable, because there is no reasonable prospect that it will be fulfilled within the lifetime of the permission?

Practical considerations

In cases where the water company already has a funded improvement scheme in its five-year investment plan, a condition restricting occupation until completion of those works is likely to be both lawful and defensible. The local planning authority can point to a clear, time-bound programme and reasonable certainty of delivery to support its decision to impose the condition.

The use of such conditions was recently supported in Wealdon District Council, where an appeal inspector supported the Council’s refusal to remove a Grampian condition restricting occupation pending foul water capacity upgrades, where such works had not been done, and the Council remained concerned that the new residential connections would result in overspills.

By contrast, conditions which impose a similar restriction but based on commencement of development, rather than occupation, should be used with caution. In the context of a standard 3-year implementation period, such a condition may be more difficult to defend where any capacity upgrade works are merely aspirational or unfunded.

Conclusion

It is lawful for local planning authorities to grant permission for residential development subject to a condition preventing occupation until wastewater treatment upgrades are complete - but only where the condition meets the six tests. Properly used, such conditions offer a pragmatic balance between housing need and environmental protection and provide a useful reminder that, in planning as in plumbing, you cannot simply pour more in and expect the pipes not to burst.