Latest news from Loughborough University

23 Nov 2015

New research into daylight exposure in heritage buildings to help balance access and conservation

The Smoking Room at Ickworth House.

New research into the distribution of natural light and its level of exposure in historic buildings has been carried out by Loughborough University on behalf of the National Trust.

John Mardaljevic, Professor of Building Daylight Modelling in the School of Civil and Building Engineering, has been using high dynamic range (HDR) imaging to measure where the natural light falls at different points throughout the day and over several months in the Smoking Room at Ickworth House near Bury St. Edmunds, Suffolk.

As is the case with the majority of its historic buildings, the National Trust is keen to balance visitor enjoyment with the preservation of paintings, textiles and furniture that are vulnerable to light fading and ageing.

As a result of his new research, Professor Mardaljevic was able to show the distribution of light exposure across all surfaces which were of interest in the rooms, so that a comprehensive evaluation could be made of the illumination conditions over long periods of time. He did this with the help of a camera tethered to a computer that controls a sequence of exposures which occur every 10 minutes. These exposures were then converted into physical measures of the light level as it falls onto a surface at different points.

Professor Mardaljevic said: “In any heritage building the light will vary across the walls depending on the arrangement of windows and the time of day. This is the first time, however, that we have been able to use HDR in a heritage setting to create a cumulative luminance image, from which a physical measure of illumination exposure across the camera’s wide-angle perspective is derived.

“Together with the HDR measurement, we are using a technique called climate-based daylight modelling to predict how the long-term daylight exposure can change when, for example, opening hours are increased. Used together, these two techniques are a great way of better understanding natural light, especially at a time when historic houses are being encouraged to extend access and opening hours where possible.”

As a result of this research, which was conducted in partnership with Cannon-Brookes Lighting and Design, the National Trust is looking into the feasibility of revising the daylight management guide for its historic houses which takes into consideration the scheduling of the use of shutters/blinds in each of the rooms.

Dr Nigel Blades, Preventive Conservation Adviser at the National Trust, said: “The research is enabling the National Trust to understand better than ever before, the fall of daylight onto light sensitive surfaces in historic showrooms.

“We are learning how the daylight received accumulates through the days and seasons of the year. This knowledge will enable us to understand the impact of extended opening hours on light exposure. Based on the research, we will fine tune our use of daylight to minimise the rate of change in light sensitive objects, while providing sufficient daylight for visitors to enjoy our collections.”

  • The last 20 years have witnessed a marked reassessment of the function and evaluation of natural illumination in buildings. Professor Mardaljevic will describe these recent advances in his inaugural lecture using illustrations from a diverse collection of projects carried out over the last two decades. The lecture, titled Daylighting of Buildings: 2,500 Years of History / 20 Of ‘Revolution’, will be held in Loughborough University’s Lecture Theatre CC021 (James France Building) at 5pm on Wednesday 2 December.

Notes for editors

Article reference number: PR 15/214

Loughborough University is equipped with a live in-house broadcast unit via the Globelynx network. To arrange an interview with one of our experts  please contact the press office on 01509 223491. Bookings can be made online via www.globelynx.com

Loughborough is one of the country’s leading universities, with an international reputation for research that matters, excellence in teaching, strong links with industry, and unrivalled achievement in sport and its underpinning academic disciplines.

It has been awarded five stars in the independent QS Stars university rating scheme, putting it among the best universities in the world, and was named University of the Year in the What Uni Student Choice Awards 2015.Loughborough is consistently ranked in the top twenty of UK universities in the Times Higher Education’s ‘table of tables’ and is in the top 10 in England for research intensity. It was 2nd in the 2015 THE Student Experience Survey and was named Sports University of the Year 2013-14 by The Times and Sunday Times. In recognition of its contribution to the sector, Loughborough has been awarded seven Queen's Anniversary Prizes.

In September 2015 the University opened an additional academic campus in London’s new innovation quarter. Loughborough University London, based on the Queen Elizabeth Olympic Park, offers postgraduate and executive-level education, as well as research and enterprise opportunities.

Contact for all media enquiries

Charlotte Hester

PR Officer
Loughborough University
T: 01509 223491
E: C.L.Hester@lboro.ac.uk