The application has been referred by the councillor to the committee, meaning that officers cannot grant it permission ‘behind closed doors’; instead it must go to the public planning committee.

What is the referral process? The council process is this: an application to which there is widespread objection is referred to planning committee for determination if: - a ward member refers it - or if a set number of objections from the public is reached - or if the local Residents’ Association refers it.
These are available on the Croydon Council Website
There is a widespread misunderstanding that the more people who object, the better. It is certainly true that having lots of objections doesn’t harm the case for refusal, but it also doesn’t add to it. There is a fundamental principle of national, regional and local planning law that essentially says that the fact that local people don’t like a development is not a reason for it not to go ahead. So what matters is that one person makes the ‘right’ objection under planning law, rather than thousands of people making the ‘wrong’ ones.
The most normal reason for the refusal of an application is because it significantly contravenes national, regional or local planning policy. Development that contravenes policy is not impossible, but the good it does must significantly exceed the harm it does in contravening policy to enable the local authority to approve it. People often think that if they can demonstrate that a development is not policy-compliant in one area, then this must mean that it cannot be given planning permission. This is not the case in planning law. In essence the decision makers are asked to weigh up the positives of a development against the negatives.
The current administration has been responsible for the adoption of its new ‘local plan’ which was approved in 2018. That allows - in fact encourages - a lot more suburban development. That is particularly articulated in its widely-disliked SPD2 (supplementary planning document 2) which sets out how the suburbs like Sanderstead are to be intensified. This document actively promotes increasing the density of development in the suburbs through back-garden development and the demolition of larger houses to be replaced by blocks of flats. The new local plan says three other things which are relevant
  • Firstly that the accepted norm for new developments is that they ought to be three storeys high plus use of roof space. So that really means that new developments ought to be four liveable storeys high.
  • Secondly that family housing should be conserved - it sets the expectation that a development shouldn’t allow a reduction in the availability of three-bedroom family accommodation. This is why so many of the flatted developments coming forward now contain one or two three bed units. In this way the developer can claim (and have accepted by the council) that there is no net loss of family housing. It is quite specific to three bed units. Going from a four or five bed house to a block of flats with one three bed flat included is considered, by the council, to be perfectly acceptable and to result in no net loss of family accommodation. Lockdown has proven to me, beyond reasonable doubt, that it is far better for families to live in houses with private gardens than blocks of flats with little amenity space and none of it private. But that’s not what Labour’s local plan sets out.
  • Thirdly that nowhere in the borough can be exempt from intensification. All areas will be intensified, some areas super-intensified. There isn’t a super-intensification zone in Sanderstead, but there are in Kenley, South Croydon, Purley, Selsdon and other places nearby.
The examples given by Croydon of when an application might go against planning policy are set out below.

This can include:
  • harm to trees
  • significant loss of light
  • ongoing noise after construction
  • new windows or spaces that overlook your house or garden
  • traffic congestion
  • design not in keeping with the area
So when you raise an objection it is recommended that you include some or all of these points.
The key to having an application refused is (in any ‘fair’ authority), to demonstrate that it is not compliant with policy. Policy includes big issues, but also some quite micro ones considering the impact of the proposed scheme on neighbours, the street scene or wildlife. The council’s local plan sets out dozens of types of micro policy, but the ones that most commonly relate to infill developments relate to: - impact of the development on neighbour privacy or loss of light - impact of the development on the street scene where they might create a terracing effect or be excessively dominant and overbearing - impact on protected trees, or protected species like bats or badgers - poor design - this is a rather nebulous concept as it is very much a matter of opinion how good or bad a design is - meeting national or regional standards on room size, density, parking spaces and so on BUT - as noted above, even if a development is not compliant with certain aspects of policy it can still be approved if the committee wants to, on the grounds that the good it does is greater than the harm.
Flats deliver a lot of housing units on the available land - much more so than houses. The Council has accepted a high housing target - much greater than Bromley and Sutton - from the London Mayor which it can only meet by building tall. The London Mayor’s Plan was recently modified by a Government Inspector because its target for intensification of the suburbs was too high. In Croydon, it is the small sites target which is too high, to the tune of 8,700 units. The council could have decided to comply with this and reduce its own target by that amount, but it has decided not to do so. This means Croydon has chosen to deliver 8,700 home more than it is required to: it’s a political choice rather than an obligation. But they can only deliver it by either building on the Green Belt, or knocking down family housing to replace with flats, or both.
‘It’s out of character, there are no other flats in the area’ - In the past the Planning Committee have made it clear that there is nowhere in the Borough where it is inappropriate to build flats.

‘Its design is out of character’ - Mayor Khan’s new London Plan makes it clear that looking different from the locale is not a reason for refusal. Our policies cannot oppose the higher authority’s, so this can be used to justify allowing development which looks completely different from its neighbours - for example by being a square flat-roofed block rather than a traditional pitched roof.

’There’s not enough parking’ - local and London policies encourage public transport use by discouraging parking. Bizarrely, the London Plan has maximum standards for parking rather than minimum.

’The lack of parking means that flat dwellers will overspill park onto surrounding roads’ - whilst this is almost certainly true, in the suburbs it its easy for the committee to argue that there is physical space to accommodate half a dozen extra cars in most places on-street.
This argument can sometimes succeed in really clear cases of difficult access, but it is rare. The counter argument is that a four-bed house often has three of four cars attached to it, so the proportionate difference for the block with its six spaces is not great, and any consequential increase in risk is outweighed by the good the development does.
A good objection, is one that clearly lays out the objection in clear precise language. Ideally the objections will be linked to parts of policy which the development will be in breach of.  The objections should keep to points of policy and not divert on to areas which are irrelevant to planning such as:
  • The developer is making loads of money
  • You don't like the owner
  • The impact on property values
  • Who may or may not live in the proposed building
  • libellous, racist or offensive comments in nature
  • Noise or disruption due to the actual construction

More detailed guides can be found here and here
The Croydon policy is a public set of documentation on the councils website. You technically need to read the policy documents from top to bottom, meaning that the National Policies take precedence over the London policies with in turn override the Local policies.  However as you can imagine the National policies are deliberately more vague and coarse, allowing for the massive variation across the country.  
As mentioned in the other questions. More objections cannot hurt, it is possible your objection will contain one point which is sufficient to tip the balance in the favour of refusal. We do see some applications refused in the area generally before they get to committee.