This dataset does not contain any directly identifiable personal information.

Postcode level information is extracted from the Assessors' Portal. Postcodes are used to assign data to Data Zones. The data is cleaned to ensure that all records are located in a Data Zone within the Council area assigned by the Assessor. Records using out of date postcodes are also investigated to check that they are still placed in the correct Data Zone. Differences in total number of dwellings in a Data Zone outwith a threshold are investigated to determine if there is a reasonable explanation for the increase or reduction. Frequencies for variables (e.g. type of dwelling) are compared with earlier years' data to identify any potential issues. The results of postcode cleaning and quality assurance work are fed back to the Assessors' Portal each year.

Data on the number of dwellings is obtained from the Assessors’ Portal. It is possible that not all information held on the Assessors’ Portal is up-to-date. Assessors are only able to reflect physical changes and alterations to dwellings once they have been sold and a reconsideration of the banding has taken place. Furthermore, it may take time for changes as a result of new building or demolition to be recorded.

When using Data Zone level information on dwellings and households, changes over time can occur not only as a result of new building activity and demolition but also because of changes related to the postcodes of dwellings.

Postcode changes can occur due to improvements made to administrative systems or NRS data cleaning, re-locating postcodes which were previously allocated to an incorrect Data Zones. Differences can also occur due to postcodes being allocated to a different Data Zone because the distribution of their population has changed. These differences are likely to be minimal and have only a small effect on change over time except when looking at small numbers of Data Zones.

The statistics are also provided in Excel, PDF and CSV formats on the NRS website. They are designed to be consistent, and incorporate comparable historical data where appropriate. For the years 2003 to 2013, the areas of higher geographies have been calculated by aggregating 2001 Data Zones areas. For 2014 onwards, the areas of higher geographies have been aggregated from 2011 Data Zone areas. This means that the areas of higher geographies used to calculate dwellings per hectare are different before and after 2014, and therefore the estimates of dwellings per hectare before and after 2014 are not directly comparable.

It is the policy of the NRS to make its website and products accessible according to published guidelines. More information is available in the Accessibility section of the NRS website.

The statistics are mainly used for informing Councils’ decisions about housing need and service provision.

Data for each year is downloaded from the Assessors’ Portal in late December of that year or early January of the following year, e.g. 2022 data was downloaded on 7 January 2023. It is published in the following summer.

A small revision was made to the figures for two Data Zones in Falkirk Council area in 2012, for the years 2005 to 2009. This is to move around 20 dwellings to the correct Data Zone. The figures for the Council area and for Scotland as a whole are unaffected by this change.

Revisions and corrections to previously published estimates are dealt with in accordance with the Scottish Government Statistician Group corporate policy statement on revisions and corrections – a copy of which is available at this link.

In February 2019, we updated our methodology for allocating datazones to higher geographies to align with Government Statistical Service Geography Policy. This resulted in revisions to some aggregated figures at Electoral Ward and Scottish Parliament Constituency level.