Full text of this document
eb7 ltd 2nd Floor, Chancery Exchange 10 Furnival Street, EC4A 1AB +44 (0)20 7148 6290 info@eb7.co.uk www.eb7.co.uk
Dominic Bush
Greater Cambridge Shared Planning
16th October 2025
Dear Mr Bush
Re: Daylight and Sunlight: 25/02161/FUL: Christs College Library, St Andrews Street, Cambridge CB2 3BU
Demolition of 1970s library and replacement with new library and social and study spaces and including re-provision of bridge to the Bodley Library.
Introduction
I am instructed by Christ’s Lane Action Group, a local community group, representing users of Christ's Lane, local retailers and local residents, to provide a review on matters of daylight, sunlight and overshadowing in respect of their strong objections to the above application.
The proposals, lodged in June 2025, are for the demolition of the existing Christ's College Library buildings that are adjacent to Christ's Lane. The replacement proposals significantly increase the height of library with a proposed building of four to five storeys along Christ’s Lane plus the addition of five large chimney structures which extend a further 2.6m beyond the proposed main roof line.
Christ’s Lane Action Group are concerned about the clear amenity effects of the scheme in terms of impacts to the public amenity of Christ’s Lane (where the pedestrian footfall is understood to comprise over 10,000 daily movements), impacts to local retailers and effects to the residential amenity of local homes.
In preparing this review I have had regard to various reports and statements relating to the daylight, sunlight and shading effects of the scheme. In particular I have reviewed the documents set out below and provide commentary as to the accuracy and adequacy of this information:
- Daylight and Sunlight Report (16th July 2025): Prepared by Rights of Light Consulting - Light Levels Supporting Statement (18th July 2025): Prepared by Turley - Christ’s Lane ‘Daylight Study’ (published to planning portal 22 nd July 2025): Prepared by Grafton Architects
Copyright 2025 eb7 Ltd Registered Company Number: 06434420 VAT No: 929824875 Part of RSK Group Limited, registered in England at Spring Lodge, 172 Chester Road, Helsby, Cheshire, WA6 0AR Registered Number: 04944506
I have recently been provided with a further statement prepared by Turley dated 26 th September 2025, seeking to address the concerns in respect of daylight, sunlight and shading (alongside the multiple other planning issues flagged by my clients). Turley’s letter was supplemented by an updated technical report, prepared by Rights of Light Consulting and dated 8 th September.
Policy Background and Assessment Methodology
Both local and national planning policy advises that new development will only be permitted where it is shown not to cause unacceptable loss of daylight, sunlight amenity or overshadowing to neighbouring properties. In respect of the current application Policy 60 of the Cambridge Local Plan addresses the potential amenity effects upon neighbouring properties as follows (emphasis added):
“Any proposal for a structure that breaks the existing skyline and/or is significantly taller than the surrounding built form will be considered against the following criteria:
d. amenity and microclimate – applicants should demonstrate that there is no adverse impact on neighbouring buildings and open spaces in terms of the diversion of wind, overlooking or overshadowing, and that there is adequate sunlight and daylight within and around the proposals;”.
The submitted daylight and sunlight report correctly assesses the effects of the proposal against the nationally applied Building Research Establishment (BRE) Report 209,‘Site layout planning for daylight and sunlight: A guide to good practice’ (2022). The BRE document sets out a number of assessment criteria and target values which are explained within sections 3.4 – 3.6 of the applicant’s daylight and sunlight report.
The report acknowledges a number of instances where the application fails to meet these targets but concludes the effects to be ‘acceptable’.
Having reviewed the report in detail I have set out below a number of areas of concern or consideration in support of the objections raised by the Christ’s Lane Action Group.
Impact to Public Realm and Lack of Appropriate Shading Study
The submitted daylight and sunlight report, dated 16 thJuly, report sets out the assessment criteria for assessing shading to public amenity and open spaces at paragraph 3.6. Despite this the shading to Christ’s Lane is not considered in detail with that document.
Shading to Christ’s Lane was subsequently acknowledged in a ‘Supporting Statement’ prepared by Turley and dated 18th July 2025. This statement notes the concerns raised by the local community but is not prepared by the daylight and sunlight expert despite being dated only 2 days after the primary daylight report of 16th July. It is unclear why shading could not have been fully addressed in the expert daylight / sunlight report rather than dealt with summarily in a non-technical note prepared by the applicant’s planning and heritage advisor.
Shading to the lane and the need for building heights to respond appropriately to the context has also been recognised as wider consideration as the area has developed. For instance, when the Bradwell's Court planning application was submitted, a strong consideration by planning officers was that 'Building heights along Christ’s Lane will need to be designed to avoid Christ’s Lane becoming canyon-like and oppressive'.
The Turley note of 18th July makes a number of subjective statements and conclusions that are not supported by the shading assessment and evidence provided alongside the note. In particular the shading study supplied was not prepared in accordance with the relevant BRE criteria and, despite Turley’s statements to the contrary, it is evident that there will be additional shading potentially affecting amenity to the lane.
The Turley statement suggests that a shading study was not necessarily required as the proposal is sited to the north of the Christ’s lane. They further suggest that Christ’s Lane is a narrow and transient space which one passes through.
Taking these points in turn Christ’s Lane is aligned on a south west to north easterly axis. The proposals sit to the north west of the Lane and could clearly cause shading to the lane itself as well as the retail and residential units in the late afternoon hours. Indeed this is evidenced by the provision of an assessment undertaken by the architect during the ‘design evolution’ of the scheme such that the applicant and their team clearly had an appreciation that there may be potential shading impacts.
On the latter point Christ’s Lane may have historically been used as a more transient passageway but now has also become an area of valued public realm where people are encouraged to dwell. This is confirmed by the presence of seating including the ‘Art Benches’ at various points along the lane. The Art Benches are understood to have been installed in April 2023 by the city council 'to help support local artists and brighten up the city. Community artists are able to display their work on the benches free of charge. The spaces clearly encourage the public to dwell in an area that will potentially experience additional shading as a result of the proposal. There is also seating within the lane for the Starbucks coffee shop. This seating is understood to be in use until approximately 7pm in the evening and again may be affected by additional shading.
The statement produced by Turley was accompanied by an undated ‘Shading Study’ understood to have been prepared by the architects. Whilst Turley state the study shows ‘negligible impact on lighting levels within the lane’ it is clear that there are some changes.
These changes are most clearly illustrated by the change in shading patterns extracted below showing darker shadows cast across the lane at 6pm on the summer solstice.
Figure 1: Extract of Applicant’s Shading Study Clearly Showing Additional Effects of Scheme
The assessments of shading on other dates within the architect’s study appear inaccurate or difficult to judge. The image at 1800 on the equinox is presented in a pink blush and the images presented at 1800
on the winter solstice are effectively pitch black. Whilst this may represent a post sunset condition it clearly is not an ‘accurate and objective’ assessment as suggested by Turley.
The study presented does not accord with the BRE assessment criteria, shows only a limited angle of view, which appears to have been selected as favourable to the applicant and provides snapshots of selected dates including times where the shading effects are not legible.
It is clear that the proposal will have some shading effects which may affect the use of the lane which is not simply a transient passageway. A more comprehensive shading study would be required to fully understand the effects to the space. This should be produced by a specialist consultant and provide transient shadow paths comprising adequate dates, times and angles of view to fully enable an assessment of these potential impacts and to fully consider the concerns regarding the effect to the valuable public realm raised by the local community.
The latest additional documents, issued in September 2025, from Turley and Rights of Light consulting further seek to dismiss effects to the lane and state that ‘it is not standard practice’ to assess shading to streets. This is despite the concerns raised by local stakeholders Turley having previously engaged with these legitimate concerns in their letter and study of 18 th July. Notwithstanding the deficiencies detailed above, that earlier study clearly showed change in the shading patterns within Christ’s Lane (see figure 1).
Whilst they now seek to present the shading as irrelevant this is at odds with the guidance set out in the relevant BRE document ‘Site Layout Planning for Daylight and Sunlight: A Guide to Good Practice (2022)’ which notes:
3.3.3 The availability of sunlight should be checked for all open spaaces where it will be required. This would normally include:
- sitting out areas such as those between non-domestic buildings and in public squares.
My comments above specifically point out the characteristics of the lane as an area of public realm where people are encouraged to dwell. This includes the seating areas for the retail units and the areas of ‘Art Benches’ installed to the lane. These are areas for sitting out between non-domestic buildings and fall within the BRE guidance cited above.
The additional technical report prepared by ‘Rights of Light’ consulting includes a test of 2+hour shading to Christ’s Lane and states that this shows ‘no effect’ to the sunlight on Christ’s Lane. The 2+hour test is a point-in-time study of a single date and thus ignores our concerns that the earlier study showed only a limited angle of view and snapshots of selected dates.
The limits of the 2+hour study are illustrated in the applicant’s conclusion that there is ‘no effect’ despite the applicant’s own previous work showing the changes illustrated in figure 1 (above).
Section 3.3.12 of the BRE guide also recognises the limitations of the 2+ hour March 21 st test and states (emphasis added):
3.3.12 For critical areas, particularly in public open spaces, it is suggested a more detailed study of sunlighting potential may be carried out….by shadow plotting.
It is this shadow plotting, rather than the 2+ hour point in time study, that is required to fully assess the effects of the proposal. This should plot shadows across the areas of public realm and sitting out spaces at adequate dates, times and angles of view to fully enable an assessment of these potential impacts. Such
an assessment is not possible based on the additional information September 2025 information provided by the applicant with both the written and technical responses not engaging with the detail of the concerns previously raised.
Effects to Retail Units
In addition to the effect to the public realm the daylight and sunlight report identifies widespread and significant daylight effects to the windows serving the retail premises along Christ’s Lane.
The submitted daylight and sunlight report acknowledges these effects but deals with them summarily at paragraph 1.1.15 stating (emphasis added):
1.1.5 The ground and first floor of the neighbouring property are non-domestic, which in our opinion do not have a requirement for daylight or sunlight. Even though a number of the rooms/windows do not pass the numerical tests, this does not amount to non-compliance with the BRE requirements.
Whilst it is acknowledged that the BRE guide focuses on the potential effects to residential properties section 2.2.2 of the guide notes ‘the guidelines may also be applied to any existing non-domestic building where the occupants have a reasonable expectation of daylight’.
In respect of Christ’s Lane the affected uses comprise retail frontages and two Coffee Shops – including a Starbucks unit directly opposite the proposals that has seating areas close to the windows overlooking the lane benefitting from both outlook and natural light. Given the significance of the loss to these spaces it cannot be automatically assumed that they do not have a requirement for natural daylight.
In total 35 windows serving the retail and coffee shops along the lane are identified as suffering losses beyond the BRE targets. A number of these are very severe impacts representing both major reductions from the pre-existing condition and very poor retained amenity levels.
11 windows retain exceptionally poor VSC levels of less than 5%, compared with an absolute target of 27%, and two windows would experience no sky visibility at all with the development in place.
25 windows experience reduction factors exceeding 50% with the proposal in place, compared with the BRE guideline target of 20% reduction. Four windows experiencing over a 90% reduction in VSC daylight levels.
The effect to the Starbucks unit is particularly severe with the windows identified as 7-10 in the analysis serving the main frontage and entranceway to this space. These windows experience reductions of reductions of 55%, 75%, 87% and 96% respectively. The primary window 7 experiences a reduction from more than 20% VSC to less than 10% which will be a significant noticeable effect. The remaining windows retain VSC levels of less than 2% which is exceptionally low and will not assist in mitigating the effect of the proposals.
The effects noted above represent significant deviation from the BRE targets and may materially affect the use of the spaces despite the non-residential uses. This is particularly the case given the already constrained position and outlook across the lane. The nature of the units, and in particular the coffee shops, means they may have a reasonable expectation and reliance on daylight amenity and these effects should be a consideration when weighing the acceptability of the scheme.
The latest statements in September by Turley and Rights of Light consulting acknowledge that the BRE guidance may be applied to non-domestic buildings but state the effects to the retail frontages on Christ’s Lane are ‘not a material planning consideration’. Ultimately the weight to be given to such effects is a matter for planning officers and committee members although I direct them to the very significant impacts noted above.
Effects to Residential Amenity and Accuracy of Modelling
The daylight and sunlight study submitted by the applicant identifies the flats at Bradwell Court as the sole residential receptor relevant for detailed assessment. The report presents the Vertical Sky Component and No-Sky Line analysis in detail at appendices 1 and 2.
A deviation from the BRE guidelines is noted in respect of ‘VSC’ levels to window ‘76’ of the daylight study. This window is correctly identified as serving the main living / kitchen /dining space of Flat 7 Christ’s Lane and I have had a specific dialogue with the owner of this flat whist preparing my review.
It is acknowledged that window 76 already has a lower VSC level due to being recessed beneath the roof line of Bradwell Court. The window does however experience a further 33% reduction in VSC when compared with the BRE target 20% reduction factor. Whilst the effect of the overhang above this window is noted to increase the sensitivity of the window the effect to this space cannot be dismissed. Paragraph 2.2.7 of the BRE guide states that VSC changes exceeding 0.80 times the former value will mean that the area lit by the window is likely to appear gloomier, and electric lighting will be needed more of the time. This represents a critical concern for the occupier of flat 7.
In addition to the impact upon this main living space the owner of flat 7 has also identified an error in the technical modelling upon which the daylight /sunlight analysis is based. This is illustrated by the image below:
Figure 2: Window map extract showing window 39
In the image window 39 can be seen to extend only to the level of the first floor retail. In reality the window continues to serve the upper floor area as shown below:
Figure 3: Photo illustrating window 39 extending to upper floor level
The position of window 39 is relevant in the assessment of the neighbouring window 76 which is recessed behind window 39. Further sky visibility may be received to window 76 through this aperture and any additional benefit or reduction cannot has not been quantified if window 39 is not accurately modelled.
The inaccuracy in modelling an area where there is acknowledged to be a deviation from the BRE targets is of concern. This is particularly the case as it is understood that ensuring an accurate assessment was raised as a key consideration between officer’s and the applicant team during pre-application discussions. When Turley noted they did not have accurate plans of Bradwell Court the officer recommended that neighbours be approached at the consultation event to confirm the layouts and / or grant access to their flats. I understand that the applicant did not contact neighbours or seek access to any of the flats to validate the findings of their survey.
In addition to above it is notable that the drawings at appendix 1 of the daylight & sunlight report, which show the existing and proposed condition alongside the context, contain no spot heights of the site levels or the proposed scheme. These are essential for confirming the accuracy of the report and cross-checking against the levels shown on the submission drawings.
Given the issues noted above updated modelling should be provided prior to the determination of the application. This should rectify the issues identified in respect of window 39 and ensure that drawings are provided that confirm the accuracy of the 3d modelling work.
In their latest submission, the applicant has acknowledged the previous inaccuracies in their daylight / sunlight modelling and states that the testing has now been appropriately amended. I do not have access to the applicant’s modelling in order to confirm this, but given these discrepancies, the Local Planning Authority may also wish to commission a more detailed technical review to confirm the accuracy of the assessments.
Inaccurate Policy Justification
In addition to the technical considerations noted above I have reviewed the narrative set out within the daylight and sunlight report. This seeks to justify the effects of the scheme and a flexible application of the BRE targets.
Paragraph 3.2 of the daylight / sunlight report cites the National Planning Policy Framework in support of this approach with the extract at 3.2,2 stating:
“Local planning authorities should refuse applications which they consider fail to make efficient use of land, taking into account the policies in this Framework. In this context, when considering applications for housing, authorities should take a flexible approach in applying policies or guidance relating to daylight and sunlight’.
It is clear from the passage highlighted above that the flexibility encouraged in the NPPF relates to the optimisation of land use for housing delivery. Housing does not form part of the current application and the NPPF is therefore not engaged in this regard.
Despite submitting an updated daylight / sunlight report in September, the applicant’s consultant has not addressed the inaccurate policy justification cited in support of their proposals, which is repeated in Paragraph 3.2 of the updated report.
Additional Harm versus Previously Consented Scheme
When instructing my review Christ’s Lane Action Group have stressed that they do not object to all potential development of the library buildings. It is the particular impacts resulting from the scale of the current design which they strongly disagree with.
It is relevant that the application site has previously benefitted from, consents relating to 2011 and 2016 planning applications (LPA refs: 11/0495/FUL and 16/0405/FUL respectively), for an earlier development proposal. This earlier scheme proposed a more uniform roof profile to Christ’s Lane and materially lower parapet than that currently proposed. The community have also commissioned CreateStreets to develop alternate proposals that have also been presented to the LPA. This scheme limits the above-ground bulk and massing similar to the earlier consented schemes and presents a more uniform and sympathetic frontage to Christ’s Lane which would have a lesser impact on the public amenity, local retail and residences. The Christ’s Lane Action Group believe that the earlier consents and CreateStreets proposals are a more considered response to the site and relationship with Christ’s Lane. They respectfully request that the planning authority compel the applicant to reconsider the current proposals and submit a revised application more in line with the principles of height, mass and subsequent amenity effects of these alternative options.
Conclusions
This practice has undertaken a review of the daylight, sunlight and shading assessments submitted by the applicant in support of the proposals at Christ’s College Library. My review has highlighted the limited consideration given to concerns raised in respect of the public realm within Christ’s Lane, impact on retail / coffee shops within the lane and the amenity to local residents. Additionally I have identified technical and policy inaccuracies within the submitted information.
Of particular relevance are the significant daylight effects to the lower floor retail elements and shading impacts to the public realm. These are dealt with summarily and, in the case of shading, are addressed through a study that has not been prepared by an expert, does not accord with the BRE assessment criteria and cannot be clearly interpreted. In respect of the impact to residential amenity my review has identified incorrectly modelled windows, in areas where effects beyond the BRE targets are noted, and a lack of detail within the report upon which to confirm the wider accuracy of the daylight study.
The submitted daylight and sunlight report already acknowledges areas of non-compliance against the BRE targets. The issues noted above should therefore be fully considered by the Local Planning Authority when considering the acceptability of the scheme and, at the least, the technical concerns must be addressed. The LPA may wish to commission a more detailed technical review in this regard.
The local community and Christ’s Lane Action Group do not fundamentally object to development of the site but are concerned by the scale and subsequent impact of the proposals. As noted above this is in particularly stark contrast to the earlier consents for the site. The local community would therefore restate their strong objection to the scheme and request that current application is refused with the applicant encouraged to consider alternative schemes. In particular the design of the earlier consented proposals, or the example of alternative design produced by CreateStreets, illustrate more uniform and sympathetic above-ground bulk and massing which would assist in mitigating the impacts on public amenity, local retailers and residents.
I hope the above is clear in setting out my client’s concerns in respect of the amenity effects of the scheme., which have not been adequately addressed by the most recent submission by Turley dated 26 th September 2025 and the additional information provided. My clients remain fundamentally opposed to the height and mass of the proposals, and request that the planning authority compel the applicant to reconsider the current proposals and submit a revised application which reduces the height, mass and subsequent amenity effects of the scheme.
I trust the above is clear but please do not hesitate to contact me should you need anything further in respect of this matter.
Yours Sincerely
Jonathan Lonergan MRICS Director For and on behalf of eb7 Limited