Was Waldram wrong?

Abstract

Purpose

The purpose of this paper is to continue the debate started by M. Pitts and P. Chynoweth in previous issues of Structural Survey and examine some specific areas of concern regarding the methodologies used for calculating loss of daylight in Rights to Light cases.

Design/methodology/approach

Eight specific areas of concern are identified and each of these is analysed in turn, first to establish, where possible, the origin of the current methodology and then to test this against available current thinking.

Findings

There is a reasonable justification for adopting a value of 500 foot‐candles, although this is not in fact the minimum value. The only justification for using a Uniform Sky appears to be mathematical and another, more accurate, sky model could be used. The Waldram Diagram can legitimately be adjusted to any suitable dimensions provided that the measurements are always taken as a ratio of the chart area. There is no justification for using a work surface height of 850 mm, nor is there any evidence of justification for assuming that 1 foot‐candle of light is adequate for normal use but there is justification in legal terms for ignoring window frames, glazing and internal reflectance.

Practical implications

It can be shown that there is a case for reassessing the methodologies currently accepted by the Courts and therefore that there is scope for further research to establish a new more accurate method.

Originality/value

Whilst many are questioning the validity of daylight calculations in Rights to Light cases, this paper takes some of those questions and establishes whether there is in fact cause for concern.

Citation

Defoe, P.S. and Frame, I. (2007), "Was Waldram wrong?", Structural Survey, Vol. 25 No. 2, pp. 98-116. https://doi.org/10.1108/02630800710747681