Garden Annexe, Caravan, or Mobile Home?

Tim Catchpole of the Mortlake and East Sheen Society writes…

Our Society has had a recent experience which we would like to share with other London Forum members who may or may not have had a similar experience.

As a rule we do not normally make comments on planning applications for any development that is not visible from the public realm. However, the application in question was for planning permission for the ‘construction of a granny annex ancillary to the main house.’ We were not going to comment until neighbours approached us and drew attention to the size of the annex and the loss of trees. So we sent a representation to the Council recommending refusal in accordance with its policies against back-garden development and, sure enough, permission was accordingly refused.

However, a few days later a new application arrived for the same site, this time for a certificate of lawful development for the ‘use of the land for siting a mobile unit for use incidental to the main dwelling.’ We inspected the drawings and discovered they were identical to those in the original application, the only changes being the removal of any reference to a granny annex and the addition of a drawing showing how the mobile home can be lowered into place. So we sent in the same representation as before only to discover that the certificate of lawful development had already been granted.

We wrote to the Council demanding an explanation and received an answer as follows:

“It is settled law that stationing a caravan on land, even for prolonged periods, is a use of land rather than operational development. This principle is embedded in the legislative framework, endorsed by case law and routinely applied by the Planning Inspectorate. Thus, the limitations in the General Permitted Development Order that apply to the erection of buildings in the curtilage of a dwelling house have no relevance to this case.

“According to the planning statement submitted as part of the application, the mobile home would be used as residential accommodation annexe ancillary to the main house on the site. The mobile home would not be larger than the existing house in terms of accommodation or scale and remain subsidiary to it in terms of use, that is to say, the mobile home would not become the ‘main house’. The submitted floor plans indicate that there would be an open plan living/dining area with kitchenette. There would be a bathroom as well as a double bedroom. In this respect, the unit has all the primary facilities required to be an independent residential unit. The presence of such facilities is not however determinative. Testing separateness and independence of residential accommodation is key to decision making.

“A personal statement has been submitted confirming the accommodation is for a family member who will continue to spend their time predominantly in the main house. Services will not be separately metered and it will not have an independent address. The garden will be shared. The LPA have no reason to doubt this, and it is noted that the backland siting with no independent street access does not lend itself well to creation of a separate planning unit. Therefore, it would not constitute a separate dwelling and could be described as residential accommodation ancillary to the main house.

“As such, the mobile home would not result in a material change of use of the site which would remain in residential use as a single dwellinghouse with ancillary accommodation.”

This response from the Council has prompted us to do a little research. First, the legal definition of a mobile home. We discovered the following: “a structure designed or adapted for human habitation that is capable of being moved from one place to another, and is legally treated similarly to a caravan under UK law.” What has been approved on this site is clearly not mobile because the back garden is not accessible from the street. Conceivably the mobile home could be brought to the house on the back of a flat-bed lorry and then carried over the roof of the house using a crane (as shown in the above illustration) and presumably, when it is time to move, the crane will return. However, the mobile home has actually arrived as a construction kit in numerous parts which have taken several weeks to assemble. Presumably, when it is time to move, the mobile home will be dismantled and then reassembled on its new site.

Secondly, the size and dimensions. We discovered that “mobile homes typically come in various sizes, with single-wide homes averaging 14 to 18 ft in width and 40 to 80 ft in length, while double-wide homes range from 24 to 32 ft in width and 40 to 80 ft in length.” Interestingly the width of a flat-bed lorry is 8 ft 6 in, so a mobile home would indeed arrive in several parts which can be assembled on site and then be partially dismantled before moving.

Thirdly, under the legislation for caravans and mobile homes there have to be occasional inspections of their condition. Under planning law the opposite is the case in that after ten years or so a temporary structure can become permanent!

So, it seems there is nothing we can do about applications for a certificate for lawful development except bite the bullet. Besides, we have come to the realisation that mobile homes provide much-needed affordable accommodation especially for the young generation who are unable to enter the housing market. Thus, the houses in London that were typically built to accommodate two generations are now having to accommodate three, possibly even four, generations. So be it – this is common practice in other parts of the world and could become so here too.