Limits of Deviation (LoD) meaning

In infrastructure consenting, Limits of Deviation (LoD) describe the lateral and vertical tolerances within which authorised works may vary from the design shown on the works plans, allowing construction flexibility while remaining within the envelope assessed and consented. In Development Consent Orders (dcos) under the Planning Act 2008, LoD are not defined by statute; they are a drafting device secured by the Order and shown on the Order/works plans. They typically comprise: (a) lateral LoD (a corridor within which the alignment may move) and (b) vertical LoD (maximum upward/downward deviation expressed in metres). The promoter must explain and justify how the LoD have been derived—commonly in the environmental statement, engineering/design documents and during examination—so the Examining Authority can be satisfied that environmental effects, land requirements and any compulsory acquisition are properly assessed. LoD operate within the Order limits; they do not authorise works outside those limits or beyond the stated vertical tolerances. Usage is broadly consistent across England and Wales (DCOs and Transport and Works Act Orders), Scotland (Transport and Works (Scotland) Act orders) and, by analogy, Northern Ireland (infrastructure orders, though the DCO regime does not apply). In Ireland, LoD are commonly used in railway orders and some strategic infrastructure consents.