Planning and polytunnels - John Sones looks at recent case law involving polytunnels and related planning issues

Hall Hunter v First Secretary of State and others (2006) was an appeal against the decision of a planning inspector who had decided that "Spanish polytunnels" - described as large walk-in plastic tunnels - were a building operation. As such, they constituted a development under the Town and Country Planning Act 1990 and therefore required planning permission, which they did not have. The appeal was refused, thus deciding that on the merits of this particular case, planning permission was required.

Important factors in reaching this decision were the type and scale of the polytunnels, their size, degree of permanence and physical attachment to the ground.

What factors will planners consider?

The key question is, is a polytunnel a building operation or a use of land? If it is deemed to be a building operation, this is a development and may require planning permission. If it is a use of land, no planning permission is required under the terms of section 55 (e) of the Town and Country Planning Act 1990 which states that the use of land for agriculture or forestry does not constitute development.

There is case law in addition to the one mentioned previously about what is or is not a building operation but this can sometimes muddy the waters rather than make it all clear. Each case will be looked at on its own merits so the 2006 case does not mean that every "Spanish polytunnel" now requires planning permission.

Three main aspects will be considered: size, permanence and physical attachment. Relating these criteria to Hall Hunter v First Secretary of State and others, their operation was on a large scale:

• The height of the polytunnels varied from 3.2 metres to 4 metres, in length from 50 metres to 100 metres and in width from 6.8metres to 8 metres. The area covered varied from 34 hectares to 43 hectares.

• They were in place from between three to seven months in any one year.

• The legs were screwed into the ground using machinery to a depth of 0.6 to 1.0 metres.

This was not your average smallholder! To further put it into context, the Hall Hunter Partnership owned the 470-acre Tuesley Farm in Surrey. They bought the farm in 2004 and subsequently installed the polytunnels, windbreaks and caravans for up to 250 workers. The farm is situated in Green Belt land inside an area designated as of great landscape value. It could also be seen from the nearby Surrey Hills, which is an area of outstanding natural beauty.

The Inspector in this case decided that the polytunnels were therefore of a substantial size and proportion, that even the shortest period was sufficient to be a consequence for planning purposes and that they had a substantial degree of physical attachment to the ground.

He also made it clear that his findings did not apply to all polytunnels.

Does the size of holding matter?

For any proposed development, not just polytunnels, the size of a holding is extremely important. If a holding is of five or more hectares then there are certain permitted developments which a local authority cannot refuse provided that they meet all the requirements of the Town and Country Planning (General Permitted Development) Order 1995. Part 6 relates to agricultural buildings and operations and allows for the erection of a "building" which is reasonably necessary for the purposes of agriculture within that unit. Thus a polytunnel may be covered by this and thus not require planning permission. However, if several are proposed then there are restrictions on size and where sited. For example, the area such a "building" can cover is 465 square metres and they must be at least 90 metres from another building. The planners may also be more likely to question the need for several rather than one or two.

A word of caution here. This exemption relates to "purposes of agriculture". So for example the provision of stables for horses cannot be classed as permitted development as horses are not deemed to be agriculture unless they are used on the land. You may also have a problem if you have an existing disused building which could be used for the purpose that you propose as the planning authority may argue that a new building is not "reasonably necessary". In my experience, the provision of a new building will be resisted wherever possible.

The local planning authority must be given 28 days notice of any proposal for a development under this section which they can challenge.

If your holding is less than 5 hectares but not less than 0.4 hectares, Part 6 referred to previously also allows for the extension or alteration of an existing agricultural building but not for the erection of a new building.

Should you have inadvertently contravened the planning regulations by erecting a polytunnel without planning permission when it is required, the local planning authority can take enforcement action to make you remove it. However, advice from the Government's chief planner is for them to take into account "the harm which has been, or may be, caused to local amenity. If there are no planning objections to the unauthorised polytunnel, there may be no need for a local planning authority to take enforcement action merely to regularise the situation. The better course of action is to invite a retrospective planning application".

You cannot of course guarantee that your local planning authority will follow this advice.

There are certain circumstances when you may have a defence to any enforcement action. The grounds for an appeal against an enforcement notice include the following: That at the time the enforcement notice was issued it was too late to take enforcement action against the matters stated in the notice.

Two periods of time are relevant here; four years and ten years. These were introduced by the Town and Country Planning Act 1990 after which times as explained below enforcement action is not possible against a breach of planning control.

The four-year rule: Any building, engineering or other works which have happened without the appropriate planning permission and have remained unchallenged by enforcement action for four or more years cannot have enforcement action against them. Thus a building which goes undetected for four years will be allowed to remain.

This does not protect the use to which the building is being put and so we come to the The ten-year rule: Any change of use of land and buildings must have existed unchallenged for in excess of ten years to be protected from enforcement action.

If we now consider two scenarios: A polytunnel which does require planning permission both for its siting and use is used for growing vegetables for five years without the required permission. The local planning authority becomes aware and decides to take enforcement action. The structure is protected and will be allowed to remain under the four-year rule but you may not be able to continue to grow vegetables in it.

Alternatively, in the same circumstances, the planning authority find out after 11 years. This time they cannot do anything as its use is now also protected. You will of course have to prove your case in terms of the time periods but you can also then apply for a Lawful Development Certificate which legitimises the situation both for the "building" and its use.

Conclusion The Inspector in the 2006 case specifically listed some "portable" items which are not buildings and therefore do not generally require planning permission when brought on to agricultural land. These include "low tunnels", "French tunnels", covers for cherries, pig arks, chicken houses, cloches, huts for agricultural uses, hop poles and polythene sheeting and nets and fleeces for covering plants at ground level.

In my experience, planning decisions appear to be to a certain extent subjective particularly in that what one authority will allow another won't. I feel it is very risky to make assumptions based on what your neighbour has done especially if they come under a different local authority. My advice is to speak to your local planning authority before putting up a polytunnel or any other building (or extension). It may also be useful to write to them with a plan of your holding showing the location of the proposed polytunnel, building or extension. You need the planners on your side and by seeking advice from the start, hopefully you will achieve what you are requesting. The last thing you want is to build up a business involving polytunnels and then find yourself in the middle of a planning enforcement action. Problems could also occur if you decide to sell an existing business and do not have the required planning consent or proof that it is a permitted development.

I am not a planning expert and professional advice should always be sought before erecting anything which may require planning permission.