Paper short abstract:

This paper explores British architects’ use of the daylight factor, considering how this metric shaped architectural practice. It shows architects did not routinely quantify daylight when designing dwellings, but knowledge of how to do so enhanced architects’ understanding of daylighting principles.

Paper long abstract:

British post-war planning guidance proposed that cities be rebuilt according to scientific principles. Mathematical tools were devised to determine built form; daylight levels within buildings were to be evaluated using a metric called the daylight factor. The daylight factor is still the principal metric used in daylighting guidance, despite recent calls to replace it with other metrics. This paper explores the role played by daylight-factor-based standards in shaping architectural practice. Focusing on housing, particular consideration is given to whether the Modernist ambition, for buildings to be designed according to mathematically verifiable principles, was realised in relation to daylighting. The paper draws on eleven semi-structured interviews with practising and retired architects, lighting consultants and a planning officer. Interviewees reported that planning authorities rarely required architects to prove that proposed dwellings achieved specific daylight factors. Architects interviewed for the study reported that they did not routinely evaluate daylight factors at the design stage. Interviewees described the process as time-consuming, and often unnecessary as windows can be designed without undertaking a calculation or a photometric model study. However, those architects who were knowledgeable about daylight factors reported that this knowledge enhanced their understanding of daylighting principles. In this way the daylight factor helped to establish objective standards, even though the post-war vision of architectural design as a form of computation was not realised. The paper's findings chart socio-material aspects of planning and contribute to the growing body of literature on the role played by standards in shaping urban form.