This theme is focused on estimating the size and composition of the population of the United Kingdom at a fine spatial resolution. It provides data on the people and households which use the wide range of key infrastructure modelled by the ITRC.

Scenario projections provide the data needed to estimate future demand. Data acquisition and cleaning are dealt with in models which draw on estimates published by the UK’s statistical agencies as well as Census data. These are made consistent and used in models which produce individual level population and household estimates at small area scale for the whole country.

An assignment algorithm places people in to households and a projection model produces estimates of the future size and distribution of population under different scenarios. The resulting output from this suite of models is extremely detailed data on the location and composition of population and of households, offering information about demographic attributes needed to derive demand estimates.

The result is data outputs which provide insight in to local area demand which has not previously been available on a national scale. These households are then allocated to individual dwellings using the Urban Development Models, providing further detailed estimates on the precise location of demand.

Illustration of the estimation process: population estimates are produced at Middle Super Output Area scale, Households at the Output Area scale. These are then assigned to residential dwellings to produce high resolution demand estimates.



Projections are primarily constrained to official headline data produced by the UK’s National Statistical Agencies, although there is scope to produce completely custom projections based on either varying the headline growth assumptions, or optionally by changing local area constraints to produce bespoke small-area scenarios.

Figure 1: (a) An illustration of headline population projections for Newcastle under a principal, high and low variant; and (b) a projection of both people and households for Newcastle under the principal variant.

Detailed, spatially disaggregated estimates and projections of the size and composition of the population of the United Kingdom. These are available by age, sex and ethnic group.

Figure 2: Example output showing (a) population growth in tower hamlets between 2011 and 2021; and (b) the age sex structure of the Bangladeshi population in 2021. Source: Lomax, N. and Smith, A P. (2017) Microsimulation for demography. Australian Population Studies, 1(1): 73-85.

Detailed, spatially disaggregated estimates and projections of the size and composition of households in the United Kingdom. These are disaggregated by a number of attributes including household composition, tenure and property type.

Figure 3: Example output showing change in housing density in Exeter in 2039, compared with 2011.

Custom projections of population and household change under local-area scenarios.

Figure 4: Example of two population change scenarios within the CaMkOx Arc (red is gain, blue is loss): (a) new towns scenario; and (b) expansion of existing centres.



The high resolution population and household estimates and projections can be used in a huge range of applications where the demand for infrastructure or services needs to be estimated. The outputs from the demographic models inform the infrastructure models produced by the ITRC, but could also be of use for forecasting demand for jobs, school places and housing. Indeed wherever policymakers, local authorities, construction or infrastructure companies need to make planning and investment decisions, demographic inputs are needed.

Results from the demographic models have been used by the National Infrastructure Commission to assess the potential employment and population distribution for English cities under different transport and housing scenarios. This analysis was used in the evidence published in the National Infrastructure Assessment.

The models which make up the demographics theme of ITRC are open source and allow anyone with appropriate technical expertise to undertake scenario projections. This has been made more user friendly through the development of the SIMIM model, complete with a geographical user interface which allows users to set assumptions about local area changes in housing and employment.

The model is hosted on the Data Analytic Facility for Natonal Infrastructure and has informed scenario planning around the Arc.

Screenshots from the SIMIM Geographical User Interface, hosted on the DAFNI website. These show (a) the configuration page where a user an set assumptions about house building and job growth in an area; and (b) the interactive results page.




Demographic data from census, mid-year estimates and other data sources is collected and made consistent by the UKCensusAPI mode. UKCensusAPI feeds data directly to ukpopulation and to household microsynthesis.


Official projections for the UK are downloaded and made consistent by the ukpopulation package, which provides the headline constraint data for the baseline scenarios.


Household microdata are created using the household microsynthesis package which combines census data on occupied households, communal residences, and unoccupied dwellings to generate a synthetic population of dwellings classified in a number of categories. Data are fed from UKCensusAPI.


Population microdata are estimated using the humanleague package. Data are fed from UKCensusAPI.


The microsimulation package takes the population and household synthetic data and projects these forwards in tome, constraining if required to data from ukpopulationInputs from household microsynth, humanleague and constraints from ukpopulation.


Custom scenarios can be created in simim, a spatial interaction model which takes in to account user assumptions about the development of housing, transport connectivity and the strength of the local economy in a specific region. Inputs from humanleague. Output can replace ukpopulation constraints.



ukpopulation: unified national and subnational population estimates and projections, including variants

UK statistics agencies (ONS, StatsWales, NRScotland and NISRA) produce mid-year population estimates (MYE), national population projections (NPP), and subnational population projections (SNPP), ... read more

Effects of capacity constraints on population and employment distribution

The report is intended to provide an overview of data and methods produced in accordance with the following deliverables under two phases of the project: Phase 1: Developing a baseline projection read more

humanleague: a C++ microsynthesis package with R and python interfaces

humanleague is a microsynthesis package for R and python, with its core implementation in C++. It provides both traditional and novel algorithms for generating synthetic populations from two or ... read more

UKCensusAPI: python and R interfaces to the nomisweb UK census data API

Nomisweb (“Nomis – Official Labour Market Statistics” 2017) provide an extremely useful API for querying and downloading UK census data. However, in practice data queries must be built manually ... read more

Microsimulation for demography

Background: Microsimulation consists of a set of techniques for estimating characteristics and modelling change in populations of individuals. Aims: To demonstrate how microsimulation can be used read more

Population synthesis with quasirandom integer sampling

Established methods for synthesising a population from geographically aggregated data are robust and well understood. However, most rely on the potentially detrimental process of integerisation ... read more



New tools bring unique insights for policymakers and planners

New tools bring unique insights for policymakers and planners

The UK Infrastructure Transitions Research Consortium (ITRC) is the driver behind much of the UK’s groundbreaking research into infrastructure modelling and analytics; analysing future 5G network read more

PopNation predicts household distribution to incredible level of detail

PopNation predicts household distribution to incredible level of detail

PopNation is a projection of people and households at a high spatial resolution to model, analyse and understand infrastructure demand. Before this development, the highest resolution information read more