The Bartlett School of Architecture


Liam Thomas Bolton

Image: Liam Thomas Bolton. Source: London Development Database

Cartographies of Rooftop Housing: Techniques for Mapping Airspace Development in London

First and second supervisors 


Airspace development, or rooftop housing, has recently been promoted by government and industry as one solution to the lack of urban space and the rising demand for new homes in London. However, there is a severe lack of critical research on airspace development in London.

The objective of this research is to provide a critical analysis of techniques for mapping airspace development in London. It evaluates the strengths, limitations and applications of existing techniques for mapping airspace development. It also demonstrates new techniques and tools such as Space Ratio, the Space Ratio Chart and the Fresnel Map for the purposes of mapping and measuring airspace development. In the process, this research provides a spatio-temporal analysis of rooftop housing between 2008/09 and 2018/19 in Greater London. It additionally analyses the socio-economic and environmental implications of airspace development.

As the amount of urban space decreases, it is imperative that practitioners facilitate high-quality and sustainable upward densification through airspace development. This research will be an original contribution to the literature that could be utilised to improve the design and planning of airspace development in London.


Specialising in data visualisation, GIS and text mining, Liam Thomas Bolton has worked with research labs, local authorities, government departments, Innovation Labs, non-profits and news agencies. 

In the past, he has collaborated with The Bartlett School of Architecture, the Royal Geographical Society, BBC News Labs, the Department for Transport and Graphic News. As ex-Founder of Student Data Labs, he managed Innovation Labs that aimed to teach practical data skills to university students while tackling civic problems. He has given talks at the Centre for Advanced Spatial Analysis (CASA), the Government Digital Service, the Department for Transport and the launch of the Leeds City Dashboard.

He has a BA (Hons) in Social Policy from The University of Leeds and an MSc in Smart Cities and Urban Analytics from CASA, UCL. 


Bolton, L.T. (2022). ‘A quantitative analysis of the exoadaptivity of buildings in London’, XXIX Conference of the International Seminar on Urban Form - Urban Redevelopment and Revitalisation: A Multidisciplinary Perspective. Łódź and Kraków, 6-11 September.

Bolton, L.T. (2021). ‘Space ratio: A measure of density potentials in the built environment’, Sustainable Cities and Society, 75, p.103356.

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Image:  Liam Thomas Bolton. Source: London Development Database.