Planning Policy Guidance Notes

In the United Kingdom, Planning Policy Guidance Notes (PPG) were statements of the Government's national policy and principles towards certain aspects of the town planning framework. 
These national policy documents were originally known as PPGs and under the provisions of the Planning and Compulsory Purchase Act 2004, they were gradually being replaced by Planning Policy Statements (PPS).
On 27 March 2012 they were replaced by the National Planning Policy Framework (NPPF). In recent years prior to their withdrawal they applied to England only. They were material considerations in the determination of planning applications.
The last PPGs in force until March 2012 were:
Planning Policy Guidance 2: Green belts (1995 to 2012).
PPG 2 was a document produced by the British Government to advise Local planning authorities on national green belt policy and its consideration in the formation of Local Plans. The last version was introduced in March 2001 (original) and replaced Planning Policy Guidance (PPG) Note 2 Green belts published in January 1995.
Planning Policy Guidance 3: Housing (1992-2006).
PPG 3 advised local planning authorities on the treatment of housing within the planning process. The last version was introduced in March 2000 following the Rogers Report and replaced the 1992 version. Two updates were published on 24 January 2005 - "Planning Policy Guidance 3: Housing: Planning for sustainable communities in rural areas" and "Planning Policy Guidance 3: Housing: Supporting the delivery of new housing".
PPG3 was introduced to steer policy away from the development of large, spacious houses on greenfield sites, towards higher density development using brownfield or urban sites wherever possible. It also sought to compel developers to provide a greater element of affordable housing. Because of the slow speed at which Local Planning Authorities Local Plans were updated - and the recent changes to the planning system which abolished Local Plans in favour of Local Development Frameworks - local policy is often at variance with PPG3, resulting in confusion and a higher incidence of planning appeals.
PPG3 was replaced with Planning Policy Statement 3 (PPS3) in November 2006.
Planning Policy Guidance 15: Planning and the Historic Environment (1990 to 2010).
PPG 15 advised local planning authorities on the treatment of "historic buildings" and the wider "historic environment" within the planning process. It was introduced in November 1990 following public outcry after a number of high-profile scandals such as the threatened destruction of the Rose Theatre in London by developers. It replaced the earlier Circular 8/87 which was criticised for being ill-focused in both practical and geographical terms. Circulars 01/2001 and 09/2005, which discuss arrangements for handling heritage applications and that amend the existing "PPG 15: Planning and the historic environment", were published September 1994.
PPG 15 as cancelled and superseded in 2010 by Planning Policy Statement 5: Planning and the Historic Environment.
Planning Policy Guidance 16: Archaeology and Planning (1990 to 2010).
Originally published in 1990, PPG16 was replaced by PPS 5 in 2010.
Planning Policy Guidance 24: Planning and Noise (1994 to 2012).
PPG24 Planning and Noise was published in 1994. Noise assessments are normally requested as part of local council planning procedure. Noise tests should be conducted with a Class I noise meter for accurate results. Average noise levels (LAeq) are measured over a full 24-hour cycle - 16 hour (0700 - 2300) daytime, and 8 hour (2300 - 0700) night time. LAeq dB results provide a mean arithmetic average (dB(A)) which fall into a Noise Exposure Category (A, B, C or D), with categories B and C are usually passed with suitable noise mitigation measures put into place. 
A - Noise need not be taken as a determining factor in granting planning permission, although the noise level at the high end of the category should not be regarded as a desirable level.
B - Noise should be taken into account when determining planning applications and, where appropriate, conditions imposed to ensure an adequate level of protection against noise.
C - Planning permission should not normally be granted. Where it is considered that permission should be given, for example because there are no alternative sites available, conditions should be imposed to ensure a commensurate level of protection against noise.
D - Planning Permission should normally be refused.