Planning Inspectorate Newsletter - Issue 13

Evidence Base Good PracticeDavid Vickery

The question that exercises everyone’s minds is … “is there enough evidence to show that our Plan is sound?” 

An Inspector will be looking to see if your Plan has a focussed evidence base, limited to that essential to support or inform the policies and proposals in it, and which demonstrates that participation has properly taken place.  The evidence should be up-to-date, relevant and to-the point.  It should provide an “audit trail” demonstrating that the Plan’s strategy is founded on robust and credible evidence, with “signposts” in the text of the Plan itself (written or graphic) clearly pointing to the key evidence.  The Plan should be coherent and consistent.

 Three steps to success

There are three main steps to a successful evidence base:

Plan ahead

Think about what bits of evidence are needed to support the Plan before you start obtaining them.  Plan out what is needed, when it is needed, and that you have the resources to do the work.  In particular, think about the scope and complexity of the evidence.  How much detail do you need to go into, especially if an answer is self-evident?  If there is an overwhelming need for affordable housing many, many times more than the housing target set for the Plan, is there really a need to produce a 200 page report to prove it?

Take advice both locally and nationally.  Locally, talk to other Councils, especially those whose Plans have been found sound (see the list on the Inspectorate’s web site: PINS LDF info).  Nationally, look at the Plan Making Manual on the Planning Advisory Service (PAS) web site at: PAS Manual.  PAS also have an evidence base web page with a booklet and toolkit (spreadsheet) at: PAS Evidence.

See if you can use evidence from elsewhere.  This is especially applicable if you already have an adopted Core Strategy and the Plan is a lower level one, such as an AAP.  Use and/or update existing studies – why waste time and money doing new ones?

If you have to employ consultants, make sure you give them a detailed brief of what is required; ensure it informs the planning process; steer the consultants throughout the process (meet with them); and end with a full debrief.  You must understand the study and agree with its conclusions, because you will have to defend it.

Make sure the evidence does not go out of date and become irrelevant.  If there is a danger of this happening then probably just a small follow-up survey or report is all that is needed to bring the study’s findings up-to-date.

And at the end, when it is nearly finished, it is a useful check to go back through your evidence strategy to make sure everything worked properly.  Go through each policy and proposal in the Plan asking yourselves critically what its justification is, and what are the facts/analysis that backs this up.  Is there a clear linkage (“audit trail”) from evidence to policy?

Key evidence

The main thing is to ensure that the Plan has evidence showing that the choices made are backed up by the background facts.  In other words, that the Plan has the most appropriate strategy when considered against the reasonable alternatives (Para 4.36 and 4.37 of PPS12).  Thus background national (e.g. PPS3 & PPS12) and regional (e.g. the RSS) planning policies and the Sustainable Community Strategy should be included.  Most of the reasonable major alternatives (but perhaps not all of the smaller alternatives) should have been set out and considered in the Sustainability Assessment.  Explain clearly what options were considered and the reasons for selecting the preferred option(s).  The justification does not have to be overly complex but it should be easily understandable and based on evidence not assertion.

In terms of adequate public participation, there should be evidence of the views of the local community and others who have a stake in the future of the area (Para 4.37 of PPS12).  This is often in the Regulation 30 documents.

Beyond this, the evidence should be tailored to suit the type of Plan.  Inspectors will be looking to see that the Plan performs – will it do what it says in the policies?  For instance, for Core Strategies a Strategic Housing Land Availability Assessment and a Strategic Housing Market Assessment are vital so that it can be seen that the Plan will deliver the house numbers at the right time and in the right place. Inspectors will also want to see whether it will deliver the other desired outcomes in, for instance, employment, shopping and leisure (open space).  So are there up-to-date leisure/open space, employment land and retail studies which follow the Practice Guidance notes?  Do not, however, waste time and resources on such studies if, for example, retailing is not a significant issue in the Core Strategy.

However, it may be necessary to have a range of other assessments, depending on circumstances, on matters such as habitat, transport, gypsy/traveller accommodation, flood risk etc.  This is where the notion of local distinctiveness is relevant.  Try to avoid huge lists of very detailed local studies which do not inform policies, such as Conservation Area studies or village design guides.

You will need to ensure that the infrastructure necessary for development is costed and can be funded and implemented at the right time to serve the development (Para 4.8 of PPS12).  PAS has some detailed advice on how to produce an Infrastructure Delivery Plan at: PAS Infrastructure.  Get key partners on board and 'signed up' to infrastructure delivery mechanisms.  This can mean chasing them to get answers up front and making sure that the answers are understood and acted upon before submission.  The key questions to be addressed are a) what is the infrastructure required to deliver; and b) can it realistically be delivered in the timescale of the Plan’s phasing?  Do the best you can to predict if you cannot get clear answers from providers.

PPS12 says that the infrastructure planning process should identify and have evidence for, amongst other matters, cost and funding sources (Para 4.8 to 4.12 and 4.45).  The detail of such information could be less the further ahead one is looking.  The PPS3 15-year period split into 3 x 5-year phases with less detailed information required on each successive phase could serve as a useful model/analogy for viability and delivery assessment (developable; deliverable; broad locations).

And don’t forget the need for viability assessments of the effects on housing delivery of requirements for affordable housing (Para 29 of PPS3); building sustainability and renewable energy (Para 31 and 33 of PPS1 Climate Change); and for the many requirements which might arise from S106 Obligations and, in the future, from the Community Infrastructure Levy.  There are various viability appraisal toolkits available to help.

The evidence base should justify any Plan requirements which are above or below those set out in national or regional policies, such as tighter retail restrictions.  And in areas with cross boundary issues, the context from those neighbouring authorities must also be considered, including appropriate policy support from their Plans – e.g. the arrangements for joint working.

The Plan will also have to deal with foreseeable uncertainties (Para 4.46 of PPS12).  The Plan can’t wait for everything to be a dead certainty, so evidence to deal with contingencies (flexibility) is needed.  What evidence is there to justify detailed alternatives or a whole or part review of the Plan?

And lastly, as Albert Einstein said, “Everything should be made as simple as possible, but no simpler.”  Don’t over-complicate things.

The Planning Inspectorate is aiming to share further experience and good practice through the publication of its updated Lessons Learnt document at the RTPI Summer School in September.

This article is based on a talk given by David Vickery to a RTPI conference in autumn 2008, with additional contributions from fellow Inspectors and planners.

>> back to newsletter