A homeowner placed a mobile home on land next to their main dwelling, just outside what the council considers to be the residential curtilage. The council said it wasn't permitted development. The land sits within the Green Belt — one of the most heavily protected categories in English planning policy.
Our client owns a rural property where the main dwelling sits on Grade 4 agricultural land covered, in its entirety, by a Green Belt designation. Adjacent to the house, the client placed a mobile home for additional living and ancillary use. From the homeowner's point of view this felt like an entirely reasonable use of land they already owned, in a location that was visibly part of the same residential setting as the main house. The council, however, took a different view: in their assessment, the mobile home was outside the curtilage of the main dwelling and therefore did not fall within permitted development. An informal conversation made clear that planning consent was needed.
Green Belt policy is unusual in that it works in reverse. Most planning categories ask whether a proposal is acceptable on its merits. Green Belt policy starts from the position that almost any new development is, by definition, inappropriate — and substantial weight must be given to any harm it would cause. To overcome that, an applicant has to demonstrate "very special circumstances" that clearly outweigh the harm.
This is, frankly, the hardest end of the retrospective planning market. We were honest with the client up front: there is no version of this case that gets approval easily, and we are not going to pretend otherwise. What we can do is build the most coherent, evidenced argument possible and put it in front of the council.
The case has two angles worth exploring. The first is the curtilage question: there is a legitimate technical argument to be had about where the residential curtilage of the main dwelling ends and where the open Green Belt begins. The mobile home sits in a transitional area immediately adjacent to the existing residential use, and a careful site analysis can make a real argument that the location is functionally part of the residential setting rather than an incursion into open countryside.
The second is the openness question. Green Belt policy protects the openness of the land — the sense of unbuilt countryside — and a mobile home is, by its nature, a removable, low-impact structure. Compared with a permanent building of the same footprint, a mobile home leaves the underlying land effectively unaltered: it can be moved, the soil is intact beneath it, no foundations have been laid, no permanent structure introduced. That isn't a knock-out argument, but it is a meaningful one.
We prepared and submitted a full retrospective application that does several things in parallel:
We also discussed with the client the realistic range of outcomes: from outright approval (unlikely on Green Belt land of this kind) through to a temporary or personal consent that recognises the practical situation while protecting the Green Belt designation in the long term.
Alongside the planning statement, we prepared and submitted a full set of scaled architectural drawings — site location plan, block plan, and existing and proposed elevations and floor plans where relevant — giving the case officer a clear, accurate and measurable picture of the development to assess against policy.
Green Belt retrospective applications are some of the hardest cases in the planning system. We don't pretend otherwise. What we promise is a clear-eyed view of the prospects, an evidence-led application, and an honest conversation about what realistic outcomes look like — including the ones that fall short of full approval.
If you have placed a mobile home, an outbuilding or any other structure on Green Belt land and the council has flagged it, the worst thing you can do is wait. The clock starts the moment they make contact, and the right strategy depends on facts only a Chartered Town Planner can properly read. The first conversation with us is free.
This is hard territory. It needs experienced advice. Talk to a Chartered Town Planner today.