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Planning application documents

There can be a large number of documents submitted for a Planning Application, and it can be confusing looking at them and trying to understand which to look at to understand specific aspects of the application and decide what your views are on the application and whether to object or not.


Hounslow Council have a guide here ( ) of the documents that should be produced and submitted to them (the “Validation Checklist”) as part of a Planning Application. They also have a Naming Guide at the same location, to provide consistency in naming of documents.

There are a number of different types of applications detailed there. The 2 most important ones are explained below.


Major Planning Applications (e.g. a proposal by a developer to build a new school on open land, or to build a tower block of flats on land previously occupied by a single-storey building) are the ones that OWGRA will get involved in. The abovementioned Validation Guide lists 33 different document types that should be submitted – though others are often required in such applications. We have seen submissions running into hundreds of documents. This can require literally weeks of several peoples’ time reviewing and analysing these documents to allow us to prepare a factual and convincing response to the application.


The type of Planning Applications that many people will most likely end up reviewing and wanting to respond to themselves are Householder Planning Application (for works or extension to a dwellinghouse). This would be where you feel a proposal may impact you/your home and you wish to understand it. The documents that are required for such an application are as follows:

  • Application Form. This simply states the basic information about the Planning Application (who has submitted it, what address it relates to, what the impact will be (e.g. additional living units, etc.)

  • Location Plan. This is a plan showing the location where the proposed works would be undertaken. It is typically an outline plan of the relevant street showing the property and house boundaries with the development location highlighted.

  • Existing and proposed elevations, floor plans, sections and roof plans. These are the best way of understanding what the proposed development will look like. One set should show plans of the outside, sides, inside layout and roofline of the current building (“Existing Plans”). The other set should show what the development will look like after work has been completed (“Proposed Plans”). Often the changes are highlighted on the Proposed Plans, making it easy to see what is changing. However some simply show the Proposed Plans without any such indication, meaning you have to look at Existing and Proposed Plans side by side to understand what is changing.

  • Design and Access Statements (DASs). Major developments all require a DAS. In Hounslow DASs are also required if the site is within a conservation area and 100m² or more floorspace would be created.


A sizable part of our area does fall within Conservation Areas, so this condition will often be met. However as the “average” house in the UK has a floor space of around 80m², this condition will only be met if the proposal is for substantial additions to a residential property.


The idea of a DAS is it should explain in non-technical language the reasons for the development and the reasoning behind the given proposal along with its main features. The Council for Architecture and the Built Environment (CABE) has produced advice on what should be in a DAS and how they should be written. You can find that advice HERE.


Given that DASs are supposed to explain the applications in a non-technical way for councillors and members of the general public and are supposed to be short it is a matter of concern that in Hounslow they are now very large documents which are not given to councillors on the Planning Committee and which they are not required to read.

  • Construction Method Statement. This is only required if the application includes a proposal for a basement extension. If this is proposed and it is close to your property (or next door), this is a key document for you to review.

  • Tree Survey. This is required if the application includes a proposal to fell one or more trees that are either covered by a tree preservation order or located in a conservation area. Given the importance of trees to the nature of our area there should be very strong reasons for felling a tree e.g. if a competent specialist certifies that the tree is diseased and is unsafe to leave in place. Another possible justification would be if a rapidly growing tree was too close to a building and risks damaging the foundations. But otherwise our view is that mature trees should in general not be felled.  So, for instance, a proposal to fell a mature tree because it is “in the way” of a proposed extension, should, in our view, be challenged.

  • Environment Agency flood risk matrix. This is also listed as required if the site is in a flood risk zone 2 or 3 and the proposal is for a basement or ground floor extension. This site ( ) shows a map of the UK with flood risk areas. The OWGRA area is not at risk of flooding from rivers, the sea, surface water and some groundwater. (Note that It does not include flood risk from sources such as blocked drains and burst pipes). These are not therefore required for proposed developments in our area.

  • CIL additional information requirement form.  The Community Infrastructure Levy (CIL) is a planning charge, introduced by the Planning Act 2008 as a tool for local authorities to fund the delivery of infrastructure to support the development of their area. Proposed new developments that create net additional floor space of 100m² or more, or create a new dwelling, are potentially liable for the levy. So any very substantial extension to a property, or one that proposes to build a new separate dwelling on the site, would be liable for this levy. This is not insignificant, amounting to some £145 per square meter of development.


So the documents to look at when reviewing such an application are:

  • Existing and proposed elevations, floor plans, sections and roof plans, which show what is proposed and what it will look like

  • DAS, if one is required, which explains why the development is needed

  • Location Plan, showing where the development is sited and

  • Application Form, detailing the key facts about the development.


Others will be produced if required and should be reviewed if they relate to an area of the proposals that concern you e.g. Tree Survey if you are concerned about plans to remove some trees.

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