Self Build Timber Frame Ltd Caravans Built On-site
Self Build Timber Frame Ltd
Caravans Built On-site
2- Legal Definition of a Caravan
3- Construction Methodology
4- Mobility Methodology
5- Engineering Calculations
These notes are based on legislation contained within:
Section 29 (1) of the Caravan Sites and Control of Development Act 1960
Section 13 (1) of the Caravan Sites Act 1968
Amendment of the definition of caravan 2006
Town and Country Planning (General Permitted Development) Order 1995 Part 5 - Caravan Sites
This documents intends to serve as evidence that caravans and twin-size mobile homes supplied by the company are done so in accordance with the legal definition of a caravan.
The document first outlines the current legal definition of a caravan as set in the caravan’s act and appropriate case laws. Secondly the document explains how our caravans are designed and constructed on-site and finally 3rd party engineering calculations to demonstrate the above.
2- Legal Definition of a ‘Caravan’
The legal definition of a caravan was established in the Caravan Sites and Control of Development Act 1960. It was modified in 1968 to include twin-unit mobile homes and again in 2006 when the sizes where increased.
Section 29 (1) of the Caravan Sites and Control of Development Act 1960 defined a caravan as:
“… Any structure designed or adapted for human habitation which is capable of being moved from one place to another (whether being towed, or by being transported on a motor vehicle or trailer) and any motor vehicle so designed or adapted but does not include
(A) Any railway rolling stock which is for the time being on rails forming part of a system, or
(B) Any tent”
Section 13 (1) of the Caravan Sites Act 1968, which deals with twin-unit caravans. Section 13 (1) provides that:
“A structure designed or adapted for human habitation which:
(A) Is composed of not more than two sections separately constructed and designed to be assembled on a site by means of bolts, clamps and other devices; and
(B) Is, when assembled, physically capable of being moved by road from one place to another (whether being towed, or by being transported on a motor vehicle or trailer), shall not be treated as not being (or have been) a caravan within the means of Part 1 of the Caravan Sites Control of Development Act 1960 by reason only that it cannot lawfully be moved on a highway when assembled”.
Amendment of the definition of caravan 2006
(Permissible Additional Purposes) (England) Order 2006 Paragraph 3 of article 3 of the Social Landlords (Permissible Additional Purposes) (England) Order 2006 (meaning of caravan) shall be amended
(a) Length (exclusive of any drawbar) 20m (65.6FT)
(b) Width: 6.8m (22.3ft)
(c) Overall height (measured internally from the floor at the lowest level to the ceiling at the highest level) 3.05m (10ft)
Conforming to the Definition: Construction, Mobility and Size Tests.
Most commercially manufactured static caravans and mobile homes are prefabricated in a factory and delivered to site via a transporter, partially or fully finished. They have clearly been separately constructed and are capable of transport by road, thus conforming to the definition of a caravan is rarely an issue. However, caravans don’t have to be made in factories and delivered finished. If access is bad or for self build caravans, the structure can be built on location but in order to conform to the definition of a caravan it must meet, what’s know as, the construction, mobility and size tests.
The Construction Test. This relates to how the caravan was built on-site. A caravan must be ‘composed of not more than two sections separately constructed’ If the caravan was not constructed in this manner it may be deemed a building. ‘Separately constructed’ means one half is built separately to the other, the whole must be constructed by the method of first having two separate halves. The two halves of a caravan can be made from many pieces but they must be assembled into two separate sections, then the ‘last act’ would be the assembly of those two sections to the whole. Separately can be interpreted as meaning ‘independently’ and need not necessarily mean ‘separated’. What it clearly doesn’t mean is a caravan can be constructed totally as a whole and split into two separate sections at a later date if needs be. The halves must be ‘separately constructed’, one half then the other.
The Mobility Test. Most factory-finished caravans are delivered from off-site and have wheels and a tow bar, thus mobility is clearly demonstrated. However, some mobile homes are designed to be lifted with a crane and cradle. In order to conform to the mobility test, the decision maker would need to be satisfied that the structure would have the engineering integrity and strength to survive being moved by road from one place to another, by any of the means stated. There is no clear direction within the wording of the caravans act which requires that there should be taken into consideration the conditions which the structure “when assembled” might encounter either on the road while being moved or on the site itself. For example, it’s not necessarily required to demonstrate the practicality of a lorry to drive down any particular lane or enter/exiting a site. The mobility test refers to the structure not the site.
The Size Tests. This simply confirms the dimensions of the structure are under 20m x 6.8m. Measurements are taken from the four corners of the external walls. Internal heights are measured from the lowest point of the finished internal floor to the highest part of the finished ceiling and may not exceed 3.05m.
Single unit caravans and/or each half of a twin-size caravan are usually 10, 12 or 14 feet wide, as these widths can be transported by road with little complication. However, the regulations from the Department for Transport (Road Vehicles General Order 2003) state loads over 6.1m (20 feet) can be transported by special order. There are no clear regulations that state 14 feet is the greatest width allowed for road transport. Thus the size of a single unit caravan can be debated.
Building a Caravan On-Site: High Court Decision 1997.
Clarity was brought to the issues regarding building a caravan on-site with the case law: BYRNE v. SECRETARY OF STATE FOR ENVIRONMENT and ARUN  74 P & C R 420.
In this case a mobile home of the ‘log cabin’ construction method was assembled onsite. The log cabin was deemed NOT a caravan because it failed the mobility and construction tests. The caravan was designed to split in two separate halves but the many parts of the log cabin where assembled directly as the whole unit which could then be separated, where as the many parts should have been assembled in two separate halves and then the whole. It also failed the mobility test not because it couldn’t be demonstrated that the caravan could be lifted by jacking or by crane onto a trailer but because in doing so structural damage may occur to the building.
In this case a planning inspector ‘decided that the log cabin was not a caravan but a structure which had involved carrying out building operations on the land’. The defendants argued this and the case was taken to High Court.
The case starts by accepting ‘The difficulty in identifying the nature of the development arises from the statutory definition of "caravan"’… The form of the 1968 Act is… to deem something… as "a caravan"… if it satisfies firstly, the construction test and, secondly, the mobility test...
The Planning Inspector argues that the log cabin satisfied neither the construction test nor the mobility test. Firstly, by stating that he understood a twin-size caravan to be two caravans jointed together, meaning that the two separate halves should resemble a caravan. Importantly to future cases the Judge disagreed with this ‘There is nothing… to indicate that the separately constructed sections… were to be each identifiable as caravans’.
The case then goes on to explain how the log cabin was ‘design and assembled’. The defendants argue that although the caravan arrived in many pieces, the structure was capable of split into two parts as the ridge beam and floor sections where separate and joined only by means of bolts, it was ‘designed to be assembled onsite by means of bolts and clamps’ as per the definition of a caravan. The Judge accepts this ‘I accept that if that was all that was required in order to satisfy the paragraph’ but refers to the term "separately constructed" in the act.
‘Certainly, it is designed to be composed into two sections, then to be bolted together as the paragraph requires, but this argument disregards two words in the paragraph which seem to me to be of importance. The requirement is that the structure should be composed of not more than two sections "separately constructed". That means, in my judgment, that it was an essential part of the construction process in order to deem a structure as a caravan, that there should be two sections separately constructed’… ‘The whole was not constructed by the method of first having two separate parts’.
In this case the caravan was ‘designed’ to be assembled in two halves and it could be demonstrated the building could split in two divisible sections but because the two sections where not assembled separately prior to connection as a whole, the caravan failed the construction test.
The planning inspector went on to argue the mobility test was not satisfied either. The parties had agreed that it is impossible to tow the structure, as it has no wheels or towing bar. There was then apparently evidence as to the practicality of lifting it sufficiently to be able to place it on the back of a low-loader trailer in order then to move it as a complete unit by such means. The Inspector addressed first the practicality of lifting by crane and secondly the practicality of lifting by jacking. He does not deal with the problem of moving it once it was placed on the back of a trailer by either of those means of lifting. He does, however, in respect of jacking say: "Jacking the structure would be a potentially complex procedure and, despite the claimed strength of the 'glulam' beams, would probably carry a very real risk of structural damage" The Council's evidence as to the real risk of structural damage was not directed specifically to the circumstances of jacking but the moving of the structure if it were once lifted, whether by jacking or by crane, and deposited on the back of a trailer. "If lifted and transported in its constructed state, the base would be likely to fracture and movement would be likely to cause a significant deterioration of some structural members and possibly the roof."
The Judge ruled: "Concerning the question of whether the structure is physically capable of being moved by road from one place to another, it is clearly impossible to tow it. I heard evidence from both sides about the practicality of moving it by motor vehicle or trailer. This included lifting by crane and jacking it up to enable a low-loader trailer to reverse under the log cabin. With regard to the first, the structure lacks lifting eyes or strong points for attaching strops and is of such mass and bulk that it may well be beyond safe lifting tolerances of many cranes capable of gaining access to this site. Jacking the structure would be a potentially complex procedure and, despite the claimed strength of the 'glulam' beams, would probably carry a very real risk of structural damage. In this respect I prefer the Council's evidence to that effect. Consequently I am satisfied that the structure also fails to satisfy the provisions of subsection 13(1)(b) of the 1968 Act."
To conclude what we can learn from this case: Importance of the term ‘separately constructed’. Although the caravan was ‘designed to be assembled in two sections’ those two sections where not ‘separately constructed’… ‘The whole must be constructed by the method of first having two parts’. Secondly, to satisfy the mobility test of a caravan being moved by jacking or by crane, the caravan must have the necessary structural integrity not just a methodology of doing so. Also that the two separate halves need not resemble a caravan prior to finial assembly, meaning that don’t need to be habitable or completely finished.
Building a Caravan On-Site: Appeal Decision Secretary of State in 2002
This appeal decision is commonly used as case law to show how a ‘twin-unit’ mobile homes being built on-site was deemed correct and legal.
Appeal Decision by J G Roberts 2002 an Inspector appointed by the Secretly of State. Brentall v. Erewash Borough Council.
In this case the mobile home was also of the ‘log cabin’ construction method. The appeal decision starts by referring to the definition of a caravan in the Caravans Sites Acts. To conform to the definition of a caravan… ‘There are 3 tests to be applied to the park home: a construction test, a mobility test and a size test.
For assessment of the ‘Construction Test’ the Inspector gives case law from Bryre v. SSE and Arun (the previous case we explored) for the term ‘Is composed of not more than two sections separately constructed’. He cases the High Court Decision ‘It was an essential part of the construction process… that there should be two sections separately constructed… If the process of construction was not by the creation of two separately constructed sections then joined together… the definition of a caravan… is not satisfied’… ‘They were not (satisfied) in that case because the log cabin concerned, composed of individual timbers… had not at any time been composed of 2 separately constructed sections which where jointed together onsite’.
The Inspector examines all the evidence, including the construction of the log cabin to come to this decision that is commonly used as case law today: Though the Park Homes was delivered by lorry in many pieces I see no requirement in section 13(1)(a) that the process of creating the 2 separate sections must take place away from the site on which they are joined together. It is necessary only that the act of joining the 2 sections together should be the final act of assembly. The appellant’s evidence and photographs taken during the process of assembly… demonstrate that the two sections…. Were constructed separately. In my opinion the process fulfilled the test of section 13(1)(a).
For assessment of the ‘Mobility Test’ the appellants provide structural engineering details of the buildings integrity and a lifting methodology that was not disputed. There would be no real risk of structural damage once lifted. However, the Council argue the ‘Mobility Test’ is failed because access to the caravan site is too narrow to allow the caravan to be taken from site i.e. even if it where safely lifted onto a trailer, the trailer couldn’t get out. Here the Inspector makes a significant and important decision ‘It seems to me that it is the structure that must possess the necessary qualities, not the means of access. It is not necessary for it (a caravan) to be towed, only that it is capable of being moved my road. This means to conform to the ‘Mobility Test’ it should not fail if the caravan can’t physically be taken to a highway is access from the site is restricted, for example caravans in a back garden, only that ‘the structure’ itself ‘possess the necessary qualities’ to be transported.
Building a Caravan On-Site: Appeal Decision Brightlingsea v. Morris 2008
This case law gives clarity to the mobility test, whether it’s hypothetical or relates to the caravans specific location.
Brightlingsea Haven Limited and another v. Morris and others 2008 EWHC 1928 (QB)
In paragraphs 83 and 84 of his judgment Mr. J. Jack put the mobility issue thus:
‘The two opposing constructions are these: whether the structure must be capable of being moved by road from one place to another, with no specific places or roads in mind, or whether the structure must be capable of being moved from where it is and moved by road to another place. I have concluded that the first construction is the correct one. My main reason is that it is consistent with the purpose of the Act that, if a structure is once a caravan, it should remain a caravan if it is itself unaltered, regardless of where it is. If a lodge meeting the requirements of the section and so a caravan is assembled on a site, it should not cease to be a caravan if it becomes boxed in by other lodges and cannot be got out because lifting apparatus cannot sufficiently approach… In my judgment the test which the structure has to pass is as follows. It must either be physically capable of being towed on a road, or of being carried on a road, not momentarily but enough to say that it is taken from one place to another. It is irrelevant to the test where the structure actually is, and whether it may have difficulty in reaching a road’.
Carter and Another -v- Secretary of State for the Environment and the Carrick District Council  1 WLR 1212
This case law gives clarity to the mobility test. Twin-units must be movable when assembled as a whole. In this case The Secretary of State has taken the view that, to satisfy the definition ‘a structure must be capable of being moved as a structure (that is, in one piece)...’ This view was upheld by the Court of Appeal. The reasoning appears perhaps most clearly from the judgment of Russell LJ
Russell LJ said: "In order to qualify for the description 'caravan' in section 29 it is therefore 'the structure' that has to possess two qualities. The first part of the section provides that it is necessary for 'the structure' to be designed or adapted for human habitation. This, in my view, clearly contemplates the structure as a whole, as a single unit, and not the component parts of it. The second quality which 'the structure' has to possess is mobility. The structure has to be capable of being moved by being towed or transported on a single motor vehicle or trailer. 'The structure' contemplated by the second part of the section is, in my judgment, precisely the same structure as that contemplated by the first part of the section, not a structure which has been dismantled before loading has taken place. In my view the second limb of the definition can therefore refer only to a whole single structure and not to component parts of it."
Conclusions: The Legal Definition of a Caravan.
Documents of reference:
Section 29 (1) of the Caravan Sites and Control of Development Act 1960
Section 13 (1) of the Caravan Sites Act 1968
Amendment of the definition of caravan 2006
BYRNE v. SECRETARY OF STATE FOR ENVIRONMENT and ARUN 1997
APPEAL SECISION SECRETART OF STATE 2002 Brentall BYRNE v. Erewash
Brightlingsea Haven Limited v. Morris and others 2008 EWHC 1928 (QB) Carter and Another -v- Carrick District Council  1 WLR 1212
Any structure designed or adapted for human habitation, which is capable of being moved from one place to another. Is composed of not more than two sections separately constructed. When assembled capable of being moved.
Conforming to the Definition:
To conform to the definition of a twin-size caravan there are three tests to be applied: Construction Test, Mobility Test and Size Test.
• There should be two sections separately constructed.
• The separately constructed sections need not each be identifiable as caravans.
• The act of joining the two sections together should be the final act of assembly.
• No requirement that the process of creating the two separate sections must take place away from the site.
• It is not necessary for a caravan to be towed, only that it is capable of being moved by road.
• Within the limits of reasonable practicality, the complexity of lifting or jacking a structure onto the back of a trailer does not matter, but the practicality of moving it without very real risk of structural damage once lifted, is the test which is required.
• It is the structure that must possess the necessary qualities, not the means of access.
• Less than 20m x 6.8m when measured from the four corners of the external walls. Less than 3.05m when measured from lowest internal floor to highest ceiling.