Monday, 4 January 2016

Barn conversions – the structural issue

Anyone who has ever had to deal with a ‘barn conversion’ (i.e. the change of use of an agricultural building, usually to residential use but sometimes for other purposes) will be well aware of the structural problems that may arise, especially where the pre-existing building proves not to be sufficiently robust to allow conversion without substantial reconstruction and, in the worst case scenario, where the building collapses (or is demolished by well-meaning builders, or destroyed by fire or storm) before the project can be completed.

I have previously discussed these issues at some length in a series of five articles I published in this blog under the title “Barn Conversions again” in March 2013, and in a sixth and final article in December 2014. However, the considerable extension of permitted development rights for various changes of use introduced between May 2013 and April 2015 has given rise to further structural issues that can arise in these cases.

Some classes of permitted development within Part 3 of the Second Schedule to the General Permitted Development Order allow a certain amount of operational development in connection with some, but not all, residential conversions. However, the extent of the building operations that can be undertaken is strictly circumscribed by the terms of the Order. The changes of use in respect of which building operations are also permitted are Class M (formerly IA) (residential conversion of a shop or of premises providing financial or professional services), Class N (residential conversion of an amusements centre or of a casino) and Class Q (formerly MB) (residential conversion of an agricultural building). It is in relation to the last of these that structural issues are most likely to arise, especially if the pre-existing building is of unconventional, and perhaps insubstantial, construction.

In all three cases, the Order permits building operations reasonably necessary to convert the building to residential use (within Use Class C3 - dwellinghouses). In the case of Classes M and Q (but not Class N), development is not permitted if it would result in the external dimensions of the building extending beyond the external dimensions of the existing building at any given point. In the case of Classes N and Q development is only permitted to the extent that it would consist of the installation or replacement of windows, doors, roofs, or exterior walls, or water, drainage, electricity, gas or other services, to the extent reasonably necessary for the building to function as a dwellinghouse. This stipulation is not made in respect of Class M, but in all three classes development demolition is prohibited, other than partial demolition to the extent specified by that Class. The wording varies slightly as between these three classes of permitted development. In the case of Class M, any partial demolition must be reasonably necessary to convert the building to residential use. In the case of Classes N and Q, it must be confined to the extent reasonably necessary to carry out the building operations permitted by that Class (as listed above). A developer under Class M thus has a slightly wider discretion with regard both to the building works carried out and as to the extent of any partial demolition, compared with a developer under Classes N or Q. A prior approval application must, of course, be made in all cases.

These statutory provisions represent the entirety of the legal constraints on the building operations that may be carried out as permitted development under these three Classes in Part 3. However, there is another important factor to be considered. Section 55(2)(a) of the 1990 Act provides that the carrying out, for the maintenance, improvement or other alteration of any building, of works which affect only the interior of the building, or do not materially affect the external appearance of the building, are not to be taken for the purposes of the Act to involve development of the land. It would be excessively legalistic, in my view, to argue that the words “for the maintenance, improvement or other alteration” of the building limit the scope of the works that are covered by section 55(2)(a). In particular I would not accept that the words “or other alteration” are to be construed ejusdem generis with “maintenance” or “improvement”; the purpose of such works may well be much wider than that. Thus I would contend that purely internal works (or works that do not materially affect the external appearance of the building) can be carried out to any building at any time and for any purpose, and that they would not amount to development under the Act provided that the completion of those works does not in itself constitute a material change of use.

Impey v. SSE (1984) 47 P. & C.R. 157 established that actual occupation of the converted building is not required in order for a material change of use to have taken place, if the conversion works have actually been completed. This was confirmed by the Supreme Court in Welwyn Hatfield v. SSCLG [2011] UKSC 15, where the contrary suggestion that had been raised in Backer v. SSE (1984) 47 P. & C.R. 149 was rejected. However, (short of completing the conversion works) any internal works that might be, or might be alleged to be, preparatory to a change of use for which a prior approval application has not yet been made would not constitute an unlawful commencement of the permitted development in the absence of prior approval, nor would they be a breach of planning control.

There may be some readers who are tempted at this point to cite Somak Travel Ltd -v- SSE(1988) 55 P. & C.R. 250, where an internal spiral staircase had been installed. By virtue of section 55(2)(a) this did not itself constitute development, but in this case it was part and parcel of the material change of use (or integral to the change of use) of an upper floor to office use, and so a requirement in the Enforcement Notice to remove the spiral staircase was upheld. The essential point, though, is that this case was concerned solely with the requirements of the enforcement notice. The breach of planning permission comprised only the unauthorised change of use of the upper floor of the building from residential use to use as part of the travel agency business which occupied the ground floor.

It was not alleged, nor did the inspector or the High Court find, that the installation of the internal staircase constituted development in itself. [The unlawful change of use would not have occurred, at the earliest, until all the works necessary for its occupation as an office had been completed.] However, in order to remedy the breach of planning control, i.e. the change of use of the upper floor, the removal of the staircase was seen as a necessary step in the restoration of that floor of the building to residential use. It was for this reason that the requirement in the enforcement notice that the spiral staircase should be removed was upheld by the Court. The case simply confirmed that the requirements of an enforcement notice can go beyond the scope of the breach itself, if the additional steps required to be taken (in this case the removal of the spiral staircase) are a necessary part of remedying the breach so as to restore the premises to their previous use. (This was in line with two earlier cases - Murfitt -v- SSE [1980] JPL 598 and Perkins -v- SSE [1981] JPL 755.) It does not, however, justify calling Somak Travel in aid in an attempt to argue that there are any circumstances in which purely internal works (or works that do not materially affect the external appearance of the building) are not exempted from the definition of development under section 55(2)(a).

Bearing in mind the clear legal effect of section 55(2)(a), it is difficult to reconcile this statutory provision with the statement in the government’s online Planning Practice Guidance, as amended on 5 March 2015, that it is not the intention of what was then Class MB(b) (now Class Q(b)) to permit the construction of new structural elements for the building and, accordingly, that it is only where the existing building is structurally strong enough to take the loading associated with the external works to adapt the building for residential use that certain building opera¬tions would be considered to come within Class MB(b) [Q(b)].

This advice clearly overlooks the fact that (so long as it is confined to purely internal works or works that do not materially affect the external appearance of the building) the installation of new structural elements in the building, such as a new floor, or the addition of a mezzanine floor, structural strengthening, including a new or augmented load-bearing frame, additional or strengthened roof trusses, etc. does not constitute development at all, and is not therefore governed in any way by the scope of the permission granted by Part 3, either in respect of the change of use itself, or in respect of the operational development that is also permitted under Classes M, N and Q. The latter can clearly refer only to any external works, or works that do materially affect the external appearance of the building. There is absolutely nothing in the Planning Acts, or in the GPDO itself, that prevents or inhibits other works within the building and/or which do not materially affect the external appearance of the building, whether they are carried out before, during or after any external works permitted by the GPDO.

The restriction of building operations under Classes N and Q to the installation or replacement of windows, doors, roofs, or exterior walls, or water, drainage, electricity, gas or other services, to the extent reasonably necessary for the building to function as a dwellinghouse applies only to the external works permitted by Part 3. It has no application whatsoever to purely internal works, no matter how extensive those may be.

On the other hand, if the existing structure, and the materials from which it is constructed, are so insubstantial that the building would require almost complete demolition and reconstruction in order to meet the requirements of the Building Regulations, then this clearly falls outside the scope of what Part 3 permits (particularly as regards the limited scope of the partial demolition that is permitted). In my book on Permitted Changes of Use, I have cited an appeal decision in Bedfordshire, issued in February 2015 that confirmed this.

There have, however, been other appeal decisions where inspectors would appear to have fallen into error in determining that certain agricultural buildings which comprise, for instance, a steel frame clad with light corrugated sheet, are incapable of conversion within the terms of Class Q. In one case, in August 2015, the proposal was to replace the corrugated sheeting with timber cladding, and a roof of slate. However, the Inspector doubted that the increased weight of the new materials could be carried by the existing steel frame, which was showing signs of corrosion. No structural report had been produced to confirm that the proposed conversion could be based on the existing steel frame, and so he concluded that the conversion could not be carried out within the limited structural parameters of the permitted development allowed by Class Q. A similar decision was reached on very similar grounds in another appeal in September 2015. What both these appeal decisions appear to have overlooked is that the necessary internal strengthening could (and quite probably would) have been carried out under section 55(2)(a), and would not therefore impact in any way on the limited extent of the building operations permitted by Class Q(b).

The two specific examples mentioned above are among a growing number of prior approval appeals that have been dismissed on these or very similar grounds. In our seminar in November, members of Keystone Law’s planning law team expressed their strong disagreement with this approach to the structural issues arising in prior approval cases under Class Q, and our guest speaker Sinclair Johnston agreed with us, and showed examples of structural works that in his view are entirely lawful in accordance with section 55(2)(a). We are all agreed that any future appeal decisions which conclude that the need for internal structural alterations and strengthening of an agricultural building takes the proposed development outside the scope of the development permitted under Class Q would be open to legal challenge in the High Court under section 288 and are liable to be quashed.

At the application stage, I am also aware of one case in which the LPA refused their prior approval on the grounds that internal structural works had been carried out to the building without prior notification having been given under Part 6. They therefore alleged that the agricultural building as it existed at the time of the prior approval application was unlawful, so that permitted development under Part 3 was now ruled out, by virtue of Article 3(5). Bearing in mind the effect of section 55(2(a), this reason for refusal is clearly nonsense.

A practical way forward in future in cases where internal structural works have either been carried out already, or where they will clearly be necessary in order to facilitate the residential conversion of the building, would be to give details of those works as additional information accompanying the prior approval application, so as to demonstrate the practicability of the proposed conversion, while at the same time making it abundantly clear that those internal works do not form part of the application for prior approval because, by virtue of section 55(2)(a), they do not constitute development and do not therefore require prior approval under Part 3. The LPA should then have no excuse for alleging that the proposed development does not comply with any conditions, limitations or restrictions specified in Part 3 as being applicable to the development in question. Nor, in light of the information given by the applicant as to the purely internal works covered by section 55(2)(a), would there be any excuse for alleging that the applicant has not provided sufficient information to enable the authority to establish whether the proposed development complies with those conditions, limitations or restrictions.



  1. Dear Martin,

    Thank you for your clarification in relation to the previous article.

    "... purely internal works... can be carried out to any building at any time and for any purpose, and that they would not amount to development under the Act provided that the completion of those works does not in itself constitute a material change of use."

    I recall your imaginary speech in which Grade II-listed buildings might be exempt the requirement for Listed Building Consent, but of course that hasn't happened yet, so while Planning Permmission might not be required as per the statement above, in the case of 'any' listed building, presumably LBC still would be!

  2. In response to Passer-by’s comment today, my suggestion in an earlier blog post (not related to permitted development) that the requirement for Listed Building Consent for internal alterations to Grade II listed buildings could perhaps be dispensed with was simply kite-flying on my part. I did not seriously suggest that it was about to happen, nor is it likely in the foreseeable future.

    As regards permitted development for a barn conversion, this is not allowed if the barn is a listed building, so the question posed by Passer-by does not arise in relation to permitted development under Part 3. However, so far as internal alterations generally are concerned, the position is that by virtue of section 55(2)(a) these are not development (as explained in this blog post); however, if the building is a listed building, whatever its grading, such internal alterations will require Listed Building Consent if they would affect the character of the listed building as such. This does not apply to every conceivable alteration to a listed building; it is a question of whether the works do affect its character. In view of the fact that the present blog post is on an entirely unrelated subject, I don’t propose to be drawn into a discussion on that point at present.

  3. Dear Martin,
    A very interesting post from you again.
    I think I have a reasonable understanding of the issues discussed and I can see where you are going in terms of section 55(2)(a) but I still think it will need a test case in court.
    My question to you is, the PPG issued in Spring 2015 states "it was not our intention to permit the introduction of new structural elements to the building".

    It makes no distinction between internal or external works, but does this statement over rule the use of section 55 exemption?

    Conditions applied to planning consents seem to have the effect of precluding certain changes of use.
    Would the same principle apply here?

  4. In answer to “beech2430”, I would say that the answer is “No”. The NPPG is of no binding legal effect, and cannot rewrite or over-ride legislation. The debate, if there is one, is over the precise terms of the planning permission granted by Article 3 and the various Classes in Part 3 of the Second Schedule.

    I have been reminded of another judgment that may be relevant to this issue, and so I shall be publishing a further article on this topic shortly.

  5. Martin. thank you thank you thank you for the publication of your book .
    Had two previous refusals for my barn to class Q.
    The third attempt was heading the same way.I purchased your book in the electronic format and that evening found a little nugget of info.
    Submitted this as additional information,within 48hrs the case officer had "re-evaluated " my application and now being approved.

    "Approved subject to my agreement of a financial contribution towards off-site mitigating measures for the New Forest SPA"
    Hence my question, can the authorities impose such a condition for off-site purposes ?
    Thanks Again Martin

  6. Martin,
    I have read the legislation for Class Q again and although I am not a Lawyer, it appears to me that
    paragraph Q1(i)(i) is incredibly restrictive.

    In essence, any "building operations other than"
    those specifically detailed in (aa) or (bb) mean development is not permitted.

    Any mention of other works in an application, could in my opinion cause it to be rejected by the LPA for this reason.

    New Internal walls,would in almost every case be required, not to mention a second floor, mezzanine or staircase etc. etc.

    I am now even more persuaded that section 55 is the only way out, detailing internal works in the application as you suggest.

    Do you think that the complete absence of any mention of internal works in the Class Q wording, implies that such works are not relevant , by virtue of Section 55?

  7. In answer to the further query from “beech2430”, I intend to write another article shortly on various aspects of this issue.

  8. Thanks for all your planning information
    We are thinking about changing part of our agricultural barn to Class C1,Permitted development Class M, so that we can convert part of the barn under 150 sqm to a boarding house or holiday let. The existing barn is double this size. We would keep the rest of the barn as agricultural. Can we do this and just develop part of the barn or will we be forced to change the whole barn or nothing at all.

  9. The query raised by the anonymous enquirer on 26 January does not admit of a simple answer here. We would require formal instructions to advise on the points raised by this query.

  10. I wonder if you have a view on the following.

    A barn currently meets the criteria to be able to be converted under permitted development rights to a dwelling. A notification of intention application has been submitted to the local planning authority who have not objected and therefore do not require prior approval. The barn however falls within part of the country which is due to form part of the expanded Yorkshire Dales National Park.I assume that if nothing is done the "permission" is lost once the site falls within the National Park. In order to preserve the "permission" therefore, does the development need to be commenced or completed prior to the implementation date of the extension order?

  11. JNH raises an intriguing question. As I read the GPDO, the exclusion of permitted development by paragraph Q.1(j) applies at the time when the development is (or would be) carried out. Thus, notwithstanding prior approval (which is only approval of certain specified matters, and does not represent approval of the development as such), the designation of the National Park will preclude permitted development under Class Q (and under certain other Classes) that has not taken place by the time this designation takes effect.

    A change of use is a single event, so the development under Class Q(a) is commenced (and also completed) only when the change of use is actually made. This does not necessarily require actual occupation, but the conversion must have been completed, so that residential occupation is imminent or is imminently likely (e.g. by being available for letting). However, development under Class Q(b) commences when a material operation is carried out. To be an effective commencement of the development, the operation in question must be referable to the permitted development under Class Q(b), and so other works (for example, purely internal alterations) would not count for that purpose.

    I am not sure off-hand (and would require full instructions in order to be able to consider this more carefully) whether permitted development involving both a change of use under Class Q(a) and building operations under Class Q(b) can be regarded as having been commenced for the purpose of both developments when a material operation comprising the commencement of building works permitted by Class Q(b) takes place. It would seem anomalous if this were not the case, but in order to put the matter beyond dispute maybe the residential conversion should be completed in its entirety before the National Park designation takes effect. This would be the best way to avoid any difficulties arising if the change of use itself has not actually taken place before the National Park comes into being.

  12. Early in 2015, I received Prior Approval for a conversion under Class M(b). Since then, of course, barn conversions are now subject to Prior Approval under Class Q and I have recently submitted plans for 450 m2 within the new classification. However, rumour suggests today that the area of any approvals under Class M are included in the area permitted under Class Q.

    I have searched as best I can, but I can find no reference to this.
    Is it true?

    Thank you for your most informative resource.

  13. In reply to today’s anonymous query, this is a point I have discussed in my book on this subject. Unfortunately, the GPDO 2015 contains no specific saving provision which would make the position clear in this regard, but as I read the Interpretation Act 1978, the 450 sq m floorspace limit under the former Class MB and the same floorspace limit under Class Q must be read together, so that any floorspace converted under Class MB in the 1995 Order must be aggregated with any floorspace converted under Class Q. Thus the total floorspace that can be converted under both Classes combined is limited to 450 sq m in aggregate (not 900 sq m).

  14. I am reverting to JNH’s query of 16 February, and my response of the same date, because my colleague Ben Garbett has just reminded me of the decision of the Court of Appeal in R (Orange Personal Communications Services Ltd) – v - Islington LBC [2006] EWCA Civ 157 (in which Ben acted as the instructing solicitor on behalf of Orange). This decision may be relevant in answering JNH’s question. In giving the Court’s judgment, Laws LJ made it clear that, where an application for prior approval is required, then once a prior approval is given, the extent of the permission granted by Article 3 is clearly crystallised or defined, and such permission is effective.

    Laws LJ made the point that in a case where the planning authority grants prior approval, it would surely be unjust if the developers' inevitable reliance on the grant could be defeated by the adventitious fact of (in the Orange case) a conservation area designation. His Lordship considered that there is a strong parallel between the prior approval process and the process of the grant of planning permission by a local planning authority in the ordinary way. In that latter case, he said, it is beyond contest that the planning permission once granted cannot be undermined by a later change in the status of the land save, possibly, where there is expressly retrospective legislation or something of the kind. Prior approval fixes the particular location and details of the development and the time within which it may be carried out.

    As Laws LJ put it, this produces, in the end, fairness and overall conformity with the scheme and the planning legislation.

  15. Sorry to resurrect a post about Agricultural barn conversions but I'm struggling to find answers to a query I have regarding this.

    I have a site that has two agricultural buildings on it. A Prior Notification application was submitted to the LPA on building A and was deemed not to require prior approval for the change of use to residential.

    2 months later (following this decision) an prior notification application was submitted on building B for the same change of use. The LPA have refused this application stating that the site is not only agricultural (stating it is an agricultural/residential mix).

    Nothing has changed on the site since either application was submitted, the same information/history was submitted for both applications the only difference being it was a different LPA case officer.

    I'm not understanding how the LPA can make a different decision on two applications on the same site. Can they revoke the first decision on building A? Am concerned that I'll be heading into enforcement action if I attempt to convert building A.

    Just not sure where to look for the answer to this...

  16. In answer to the anonymous query of 28 February: - Without knowing the full facts, I cannot give a definite answer, but it seems that the LPA may have overlooked the fact that the “site” in relation to a prior approval application is defined by paragraph X as “the building and any land within its curtilage”, and “curtilage”, in the case of Class Q is confined to “the piece of land, whether enclosed or unenclosed, immediately beside or around the building, closely associated with and serving the purposes of the building , oran area of land immediately beside or around the building no larger than the land area occupied by the building, whichever is the lesser” (see paragraph X again).

    Bearing in mind these definitions, Building A could not possibly form part of the same site as,or be within the curtilage of Building B, and so the LPA would be entirely wrong if what they are asserting is that the residential conversion of Building A has resulted in “the site” being in a mixed agricultural/residential use. Assuming no other issues arise, an appeal against the refusal of prior approval would appear to stand a good chance of success, and a full award of costs should also be sought, as there is no excuse for an LPA failing to understand and apply the relevant law. Alternatively, it might be quicker to submit a fresh prior approval application, although this would involve payment of the full application fee again; there’s no ‘free go’ for second prior approval applications (unlike second planning applications).

  17. On the subject of barns - I have searched high and low but can't find an example of our current situation - so any thoughts gratefully received. I have a Client who has a no of barns, all currently agricultural. However there is one barn which is attached to his property and he would like to use the PN procedure to convert this to resi but as an extension to his house rather than creation of a new dwelling. LPA are currently unsure.

    Part Q states:
    a change of use of a building and any land within its curtilage from a use as an agricultural building to a use falling within Class C3(dwellinghouses) of the Schedule to the Use Classes Order.

    Thoughts on its use in this way?

  18. The query raised by my anonymous correspondent this morning is not one I have come across before, but if one pays attention to the actual wording of Class Q, I think the answer is straightforward. As this enquirer points out, what Class Q permits is “a change of use of a building and any land within its curtilage from a use as an agricultural building to a use falling within Class C3 (dwellinghouses) of the Schedule to the Use Classes Order”. It is clear from this wording that the C3 use need not necessarily comprise the creation of a new dwelling; it would apply equally to any change of use that brings the use of the agricultural building within Use Class C3. In my view, incorporating it as an extension to the dwelling to which it is attached would undoubtedly be “a change of a use falling within Class C3”, and would therefore come within the scope of the development permitted by Class Q.

    It would, of course, be essential that all the other restrictions, limitations and conditions applying to Class Q should be fulfilled and complied with. So, for example, if the existing house is a listed building, and the barn is physically attached to it, then by virtue of section 1(5) of the Listed Buildings Act, the barn itself is also listed (and would in that case be disqualified from conversion).

  19. I am currently in middle of an application for the conversion of a barn in an AONB.
    The planning authority are considering refusal on the grounds of the Hibbitt case. The Hibbitt case refers to Part Q applications so is it correct that the planning authority can act in this way.

    1. I take it that this query relates to an application for planning permission, as a barn conversion in an AONB is disqualified from being permitted development under Class Q.

      I saw a judgment only a few weeks ago in which the court quoted Hibbitt in a case involving an application for full planning permission. In the context this is strictly incorrect, but there are equivalent judicial authorities that apply to such cases, including in particular the decision of the Court of Appeal in Williams v SSCLG [2013] EWCA Civ 958.

      So it would be rather pedantic to complain that the LPA is referring to the wrong case. Williams (and other similar cases that preceded it) established precisely the same principle in relation to barn conversions generally as Hibbitt confirmed in relation to PD under Class Q, namely that it must be a conversion, not a rebuild (or demolition and substantial replacement). In all cases, this is a matter of fact and degree for the decision-maker to determine.