We have just come off consultation on a planning White Paper that nowhere defined what the purpose of planning was and when questioned on this the minister answered in terms of functional outputs (like housing numbers and good design) that could describe a crude bundling together of thematic disciplines rather than the unique nature of planning decision making.
Complex decision making (dealing with wicked problems) is a necessary but not sufficient component. Many complex decisions have no locational element (such as designing industrial processes). Similarly, locational decision making is a necessary but not sufficient. Many locational decisions are simple, for example in a desert with only one oasis the decision of where you grow your dates is an easy one.
So we might be getting somewhere if we say that spatial planning is about solving complex locational decisions? Not quite, this might be a good description of operational research but not necessarily of spatial planning. Operational research solutions are tractable, solvable with models. Not all spatial planning problems are. However as long as a spatial planning problem remains intractable then any proposed plan will just be a stab in the dark, and eminently contestable.
Spatial planning then is the process by which complex locational problems are made tangible and tractable. In decision theory the terms large world and small world problems are used. Small world problems are tangible, tractable and as such solvable. This requires a process of simplification of complex information and its processing through rapid, simple rules of thumb, known as heuristics. This process is not second best and is not irrational. The traditional conception of rationality as I have stated on this blog many times is outdated as information always has a cost and you can waste so much energy gathering it you lose the chance of an optimum solution.
Such rules of thumb can involve protypes, what a neighborhood with sustainable connectivity looks like, what services it has what land areas it consumes, and then fitting that the surface of potential sites within your area.
Spatial planning solutions are never single dimensional as spatial solutions solve more than one problem at once. One of my favorite examples is Watford which had a close by Hospital and football club nether of which could properly expand by themselves.
The act of planning should start not with vague spatial objectives but with a very short list of the spatial problems (goals) the plan should solve. That us a spatial distribution that achieves certain land use and/or transportation objectives.
Take a local plan for fictional Anyshire.
The problems goals might be:
- Find sites for 8,000 homes
- Achieve net zero CO2 emissions from transport
- Find a new site for Anyshire Rangers
- Find sites for 3,000 jobs
- Find a site for a new reservoir
- Minimise nitrate run off to Natura 2000 protected sites
This is not to say there cannot be other objectives (e.g. crime reduction, heath etc.) however their achievement cannot be simply evaluated in terms of different distributions of land use.
There also might be some spatial objectives that are clearly spatial but defined in the negative. This might include strict ‘showstopper’ environmental constraints such as functional flood plain SSSI, ancient woodland etc. The best way to deal with such constraints is simply to combine them and exclude them as a ‘showstopper’ layer and now the problem surface is simplified and much reduced.
This process is making a distinction between what a plan is seeking its planning problem goals, to how a potential plan is evaluated. Evaluation should be via a selected subset of SEA objectives that can clearly be measured and evaluated on a site by site basis. If some cant be used in this way (maybe soil conservation is a good example) they can’t be used in a spatial planning process, at least yet.
In some cases where there is no clear trade offs it may suffice to simplify down to only one evaluation surface – of which CO2 emissions is the most obvious in current circumstances. In many cases however their will be clear tradeoffs, such as between accessible sites and landscape impact, or accessible sites and Green Belt impact. The art side of planning is to minimize these tradeoffs. Great care should be taken to reduce the number of evaluation surfaces to no more than two or three, or else the number of options will spiral geometrically.
However where many sites are being considered the combination of such sites might seem to be ‘near infinite’ a term I hear so often from district level planners. This requires an additional simplification to strategic sites only – a process il’ll describe in a follow up article.
The above is an abbreviated section of some chapters from my forthcoming book on strategic planning methodologies.