Upward Extensions Permitted Development Rights – The opportunities and limitations

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As ministers grapple with the pros and cons of reforming the planning system, it is worthwhile looking at the changes that the government has already introduced.   In August 2020, Part 20 of the Town and Country Planning (General Permitted Development) (England) Order 2015 (as amended) came into force allowing the construction of new residential floorspace in airspace above a variety of buildings in England.

These new permitted development rights (PDR) were billed as a ‘fast-tracked approval for building upwards’ and were intended to provide a ‘much-needed boost to the construction sector – creating jobs and getting the housing market going post covid’.  As a quick reminder, six new classes were introduced under Schedule 2 Part 20:

– Class A allows new flats on detached block of flats

– Class AA allows new flats on detached buildings in commercial or mixed use

– Class AB allows new flats on terrace buildings in commercial or mixed use

– Class AC allows new flats on terrace buildings in use as houses

– Class AD allows new flats on detached buildings in use as houses

– Class ZA allows demolition of buildings and construction of new flats or a house in their place

In addition, Class AA was introduced under Schedule 2 Part 1 which allows the enlargement of a dwellinghouse by construction of additional storeys.

So, just over a year on from their introduction, how useful are the new Part 20 airspace PDRs proving to be? The short answer is ‘very useful’…if the PDRs apply (there are various limitations) and if the Prior Approval process can be successfully negotiated.  Both of these issues are discussed below.


The limitations

Whilst it may seem fairly obvious, it is important to carefully consider whether a scheme can actually take advantage of the PDRs.

Firstly, the existing building must comply with the relevant PDRs in order for them to be used.  There are a number of broad-brush exemptions across all of the classes including Article 2(3) land, which includes conservation areas and national parks, as well as listed buildings and SSSI’s.  In addition, each class has its own specific exemptions. For example, Class A can only be used on detached, purpose-built blocks of flats (all terms that are defined in the legislation) constructed between 1948 and 2018.

If it can be established that the existing building itself complies, it is then necessary to consider whether the proposed extension (or replacement building in the case of Class ZA) also complies with the criteria specified under the relevant class. The PDRs allow up to two additional storeys but there are limitations on the height, siting and design of any extension and this needs to be taken into account in the design process.

Determining whether a scheme complies with the PDRs is intended to be a tick box exercise.   The legislation and explanatory notes set out and define the criteria and, if a proposal does not comply, it cannot benefit from the PDRs.  However, as it the case with other PDRs, we are finding that there are instances where it is not necessarily clear cut whether a scheme complies with the Part 20 rights or not – particularly as there is limited case law to fall back on at this early stage.    It is therefore important to have a detailed understanding of the PDRs and their limitations from the outset in order to identify any potential risk.

One area that needs particular consideration is ‘associated works’.  In addition to the upward extension, the PDRs allow for some associated work such as ‘engineering operations reasonably necessary to construct the additional storeys and new dwellinghouses’ and ‘works for the replacement of existing plant or installation of additional plant’. Class A, AA and AB also allow ‘works for the construction of storage, waste or other ancillary facilities reasonably necessary to support the new dwellinghouses’.  It is important that all of the proposed works fall within the scope of the PDR, otherwise the scheme as a whole may not be deemed to be permitted development.  This was the case in a recent appeal where the Inspector concluded that new lift shafts were not considered to fall within the definition of ‘associated works’ permitted under paragraph a(c) of Class A. Consequently, the appeal was dismissed.  If there is any doubt over whether certain ‘associated works’ are allowed under the PDRs, it may be worthwhile considering whether the works can be designed out of the scheme or applied for under a separate planning permission.


The Prior Approval Process

Assuming a scheme is indeed eligible to use the upward extension PDRs, it is then possible to seek Prior Approval for the additional storey(s) rather than having to secure full planning permission. The Prior Approval route is intended to be a ‘fast-tracked’ route to securing consent where a local planning authority (LPA) must consider specified matters only.  Importantly, the LPA is not required to assess the proposals against development plan policies. As a consequence, there is no requirement to provide an affordable housing contribution or to justify the loss of commercial space, for example.  This makes the PDRs an attractive option for some developers.

So, in practice, how straightforward is the prior approval process and what are this issues to watch out for…

Timescale – Unlike other Prior Approval applications, applications under Part 20 do not automatically receive Prior Approval if they are not determined within 8 weeks. Instead, the applicant has a right to appeal to the Secretary of Stateagainst non-determination.  However, from our recent experience, LPAs do tend to try and determine Part 20 applications within the 56 day period.  This has the advantage of a relatively quick decision and perhaps more certainty over timescales than the planning application route.  However, the downside is that there is often limited scope for negotiating with officers and/or potential to make revisions during the course of the application.  Our approach has therefore been to ‘frontload’ applications as much as possible to ensure that the submission is robust and provides all the technical reports necessary to allow officers to fully assess the application within the prescribed period.

Interpretation of prior approval matters – The list of Prior Approval matters is fairly extensive and, to varying degrees, these matters are open to interpretation.   In particular, assessing the ‘external appearance of the building’ is clearly a subjective matter requiring officers to make a planning judgement which can sometime make it difficult to predict how a scheme will be received.  As a result, ‘external appearance’ has been the subject of a number of recent appeals.   Interestingly, two recent appeals considered the issue of whether external appearance should relate solely to the appearance of the host building itself or whether the impact of a proposal on its wider setting should also be considered.  In both instances, the Inspector concluded that it was not appropriate to consider the external appearance of the proposal in isolation (the appeals, both dealt with by the same Inspector, were subsequently dismissed as the external appearance of the additional storeys was deemed to cause significant harm).  The inclusion of ‘external appearance’ as a Prior Approval matter allows officers to insist on high standards of design for any additional storeys.  These appeal decisions also highlight the importance of effectively presenting a scheme design in its context as part of any Prior Approval submission – it is often worthwhile investing in good quality street elevations and/or CGI’s in this respect.  From our experience, in some instances, there can also be benefits in seeking to agree the proposed design as part of pre-application discussions.

Complete development – one condition of the Part 20 PDRs is a requirement to complete the development within three years (in contrast, a planning permission is usually granted subject to it being implemented within three years).   Applicants need to be mindful of this, particularly if the works are started towards the end of the three year period. The meaning of ‘completed’ has also previously been subject to debate in the courts and this may again become an issue in relation to Part 20 Prior Approvals.

In summary, upward extension PDRs are indeed proving very useful in unlocking new development opportunities which may not otherwise have been available or viable.  However, it is important to be aware that the PDRs include a fairly long list of exemptions and limitations which need to be fully understood – to avoid getting tripped up on compliance technicalities further down the line. The Prior Approval process is also perhaps not as ‘light-touch’ as it is purported to be, and any application should be accompanied by a comprehensive set of supporting documents which address all Prior Approval matters.

If you have any queries regarding upward extension PDRs, please feel free to contact one of the Firstplan team.