I don't wish to sound demeaning, but your understanding of Strategic Planning could do with an uplift, Amanda.
The information that will help you think about this in the London Borough you have selected is there, although I agree it isn't very visible.
The attached link takes you to series of documents produced by Dagenham & Barking - their Local Development Framework. This complex set of documents underpin the whole of local planning policy these days - and strategies such as affordable housing, proximity to sustainable transport are ever increasingly important. Does that matter on your modest scheme, you might ask? Well if you understand what the D&B council are seeking to promote, it helps understand how the policy might work for you. It isn't just as simple as 'can you provide x numbers of car-parking spaces'.
You can try phoning them (ask for Development Control department) but they will probably refer you to these documents - particularly the Preferred Options Core Strategy - Main Report.
http://www.barking-dagenham.gov.uk/8-leisure-e nvir/planning/local-dev-framework/plan-ldf-cor e-strategy.html