You asked
I would like to obtain annual household projections by postcode sector e.g. households for 2012 to 2037 (or even later) by postcode sector.
I understand you have the 2011 Census number of households at a postcode level.
We said
Thank you for your request. The requested information is not held by the Office for National Statistics. It may be worth contacting the Department for Communities and Local Government (DCLG) to see what they are able to supply.
https://www.gov.uk/government/organisations/department-for-communities-and-local-government