Agenda item

Report of the Interim Chief Planning Officer and Development Director.

The Committee considered a report of the Interim Chief Planning Officer and Development Director regarding Stationers Hall, Stationers Hall Court, London, EC4M 7DD – specifically, the installation of condensing units within louvred acoustic enclosure on flat roof and lowering the height of the flat roof, located to the south of the Great Hall of The Stationers' Hall. Units to serve the Great Hall, Court Room and Stock Room.

The Town Clerk introduced the item by reporting that, in addition to the Officers’ report and presentation slides, Committee Members had also received three virtual site visit clips of the site in question and a late addendum containing late representations which had been published and circulated yesterday.

The Interim Chief Planning Officer and Development Director introduced the application and began by reporting that the London Plan had been adopted on 2 March 2021 and that the reference within his report to draft policy now related to adopted policy. He went on to explain that the application before Members today was for a plant room to include four air conditioning units within a louvered, acoustic enclosure onto a flat roof of a two storey extension to the south of the Great Hall of the Stationers’ Hall. Members were shown a site plan with Officers explaining that Stationers’ Hall was both a Grade I listed building and also a scheduled ancient monument. It was also situated within the St Paul’s Conservation Area with a number of other listed buildings located nearby. Members were informed that this application affected a flat roof area which fell outside the designation of both the scheduled ancient monument and the Grade I listed building but the setting of this and its impact on these and other assets would clearly be a material consideration. The Committee were shown aerial photographs of the site in question from various angles with Officers describing the existing site as a rather dishevelled ash felt flat roof at present. From Stationers’ Hall Garden, the proposed site was depicted as being outside of the listed building boundary. Further visualisations of the proposals illustrated that the enclosure would be set behind the existing parapet walls to the south of the Great Hall.

In plan form, the Committee were shown existing and proposed roof plan layouts with the proposed plan showing the extent of the plant enclosure which would be 5.7m in length and 3.3m in depth. Members were also shown an existing and proposed cross section of the site looking North-South with the proposed cross section depicting the line of the existing flat roof. Officers reported that the original proposal had proposed to drop this roof line by 30cm but subsequent amendments to try and address various objections and other concerns reduced this further by another 30cm to a total of 60cm which would have a significant impact on minimising the visual impact of the proposed plant room. It was reported that the plant room itself would be 2.6m high.

The Interim Chief Planning Officer and Development Director went on to report that one of the critical views of Stationers’ Hall was the principal elevation of the courtyard and Members were shown photographs of the area where the plant room would be situated which was behind the port stone parapet where it would therefore be concealed from view with proposals to lower the flat roof. To further illustrate this point, Officers also shared images of the proposed cross section from East-West. It was reported that it would, however, be visible from Stationers’ Hall Garden where it would project above the brick parapet. The plant room would be conditioned to be a lead grey colour.

Members were informed that there were no daylight and sunlight issues concerning residential properties by virtue of the proposed location behind parapet walls. The enclosure would, however, be visible from a number of residential windows around the site and Members were shown visualisations of the impact of this. Officers went on to focus on the materiality and design of the enclosure which would be chamfered away to reduce its visual impact and would be conditioned to have a metal finish with a slate grey colour to match the roofing lead colour. It was reported that the visual impact of the proposal to surrounding heritage assets and views was considered to be very minor and it was therefore considered acceptable in design terms and would not harm the special architectural/historic interest of Stationers’ Hall or the character or appearance of the St Paul’s Cathedral Conservation Area or the setting of nearby listed buildings. In terms of environmental impact, an acoustic report had been submitted which demonstrated that this would not cause any noise disturbance to surrounding residents, particularly when given the number of robust conditions proposed which would, for example, limit the hours of operation of the plant to between 07:00-23:00 only and a requirement that the proposed plant screen be constructed and completed prior to the plant equipment becoming operational. In addition to this, the applicant would be obliged to undertake an acoustic assessment following installation but prior to operation to ensure that the noise from the units is ten decibels below background noise level. The proposed conditions also allowed for further acoustic mitigation to be installed should the unit fail to achieve the required noise levels. In addition, a further condition was also included which would require the units to be mounted in a way that would minimise structure born sounds. Officers underlined that with these robust and enforceable conditions in place, the proposed plant would not have an adverse impact on the amenity of nearby residents.

Turning to sustainability, the Committee were informed that this proposal formed part of a larger scheme for the Hall which included the construction of a link building between the Great Hall and the Card Room to provide inclusive access which was granted in 2019 as well as associated works to bring the Hall up to modern standards, especially in terms of sustainability and environmental performance. It was reported that event spaces within the Hall at present suffered from very significant temperature fluctuations, rendering them very hot and uncomfortable during the Summer months, which clearly impacted upon the use of these spaces but also upon the historic fabric of the scheduled ancient monument. Members were reminded that the Hall originally dated back to 1670, was rebuilt after the Great Fire and had 18^th/19^th century additions. It was highlighted that the applicant had identified passive measures to reduce temperature fluctuations within the events spaces within the building which included insulation, solar controlled window film and window seal improvements, however, it was reported that it was not possible to rely on these passive measures. There was a particular need to reduce the overheating in terms of the historic fabric of the building. In addition, the wider scheme for the Hall included an air source heat pump system, which would reduce energy consumption and carbon emissions from the building and would use electricity instead of the gas boilers of the existing system. This would mean less carbon dioxide and airborne pollutants. Finally, the Interim Chief Planning Officer and Development Director reported that the applicants had prepared ana Energy and Carbon Emissions Study for the Great Hall, Stock Room and Court Room which stated that all of these measures would result in an 80% reduction in carbon dioxide emissions when compared to the existing situation. In conclusion, the Committee were informed that the applicant had looked at alternative locations for the plant but that these were not considered to be feasible The proposal before Members had been subject to significant amendments due to the very collaborative approach taken by the applicants to engage with objectors. It was noted from the addendum report that two of the original six objections received had now been subsequently withdrawn as a result of these amendments and the condition on the hours of operation of the units. In addition, it was noted from the addendum that another representation from a Ward Member confirmed that the amendments made to the proposal and the undertaking given to residents meant that they now considered the scheme to be acceptable. Officers stated that they considered the scheme to be acceptable in terms of design, heritage and environmental impacts as well as in sustainability terms and it was therefore recommended to Members for approval. 

The Town Clerk reported that there were no registered objectors addressing the meeting today. The Town Clerk went on to introduce two speakers speaking in favour of the application – Mr Martin Ashley of Martin Ashely Architects and The Rt. Revd. Dr. Stephen Platten, Master Stationer.

The Rt. Revd. Dr Stephen Platten began by thanking the Committee for the opportunity to address them and to explain the intentions behind these plans. He referred to the ancient status of the Hall which was the historic headquarters of the Worshipful Company of Stationers and Newspaper Makers, a Grade I listed building and a scheduled ancient monument, as previously highlighted by Officers. Members were informed that the Hall remained vital as an attractive venue for the Company which received no support from public funds and was supported financially through its memberships by way of things such as subscriptions, membership events, investments, donations and loans. It was therefore important that the Hall was maintained in such a way that it continued to be a venue that people wanted to use. In addition, it was also important to look after the building in heritage terms. The Rt. Revd. Dr. Platten went on to explain that this renewal project was being funded entirely by the Company through a variety of things including the liquidation of part of its assets in its investment portfolio, donations to the Company and loans from the membership. In taking on the financial burden, the membership of the company were sparing the public purse and were underwriting any costs for keeping this Grade I building in the long run. He added that it had become clear some years ago that the facilities of the Hall needed to be improved and that there was currently no air conditioning or air cooling system within the building, neither was there a lift to move between levels making access for those with mobility issues a problem. It was recognised that these things would affect the commercial attractiveness of the venue in the long run and that air quality would become increasingly important to people, particularly in the aftermath of the pandemic. It was reported that a lack of air cooling would not only render spaces within the Hall uncomfortable during the summer months but would also have a detrimental impact on the historic fabric of the building. With this in mind, the Company viewed these improvements as essential as opposed to a luxury and had considered all of the possible ways in which the proposed air conditioning units might be sited to reduce their impact. The Rt. Revd. Dr Platten reported that the Company were particularly concerned about local residents and stated that he had written personally to some households on these plans. With residents in mind, the plans had been altered to lower the height of the store room, measures to redirect and reduce noise and vibrations from the Gallery had been built into the condenser housing and the Company had also committed to switching off the condenser units between 23:30-07:00. The Rt. Revd. Dr Platten concluded by stating that he was accompanied today by a number of colleagues who would be happy to answer any general or technical questions that members might have on the plans, the building or its use.

Mr Martin Ashley, a historic buildings conservation architect, addressed the meeting. He explained that, as well as being an architect of 40 year’s experience, he also sat as a Trustee of the Stationers’ Company Charitable Trust who would be financially supporting the development presented today. Mr Ashley explained that he was nominated as trustee by Historic England so that he could be in place to advise and comment upon the appropriateness of the Hall ‘s proposals in terms of its scheduled ancient monument and Grade I listed building status. Mr Ashley went on to state that the Hall were very grateful to the Interim Chief Planning Officer and his team for their collaboration on the plans. He explained that the proposed location for the cooling plant had been chosen after a long process and significant interrogation of the alternatives and because it had been found to be  the only possible spot that would meet the technical requirements whilst also preserving the historic significance of the site and its setting whilst minimising impact upon neighbours. He listed some alternative locations that had also been considered but subsequently ruled out – the roof of the Court Room (in this location, the plant would significantly prejudice the Grade I listed building and the scheduled monument unless it were to be set down into a roof well which would not then work technically), the roof of the Card Room (this would prejudice the significance of the Grade I listed building and would involve the removal of an 18^th century glazed lantern), the terrace of the meeting rooms that were being built (this would overwhelm the terrace and damage the Hall’s amenity offer and would also prejudice the setting of the Hall and the Garden),  the garden itself (here there was just one position where plant could be sited which would be technically possible although not advisable due to long ducting requirements. This would also significantly prejudice the Grade I listed building, the Totefield Centre – the only surviving 17^th century warehouse in the City of London – and statutory consultees had warned against this), and also the front Courtyard (this would be prejudicial to the setting of the Grade I listed building).  Mr Ashley reported that the specialist team had designed the system to operate at 12 decibels below background noise levels and had done this through a number of measures. One of these measures was introducing more plant than was actually needed so that this could run at just 50% capacity and run quieter than a plant running at full capacity. The plant would also be enclosed by an acoustic enclosure which would deal with any air borne and structural noise and had been specially designed for this location.  The system had also been designed to deal with the cooling requirement and measures had been taken through the draught proofing insulation and solar shading. Mr Ashley concluded by stating that he was content that the plans presented would have maximum benefit for minimum impact upon the Grade I listed building, the scheduled ancient monument and neighbours.

The Chair thanked both speakers for their contributions and invited any questions that Members might now have of them and the applicant team present today.

A Member spoke to underline that she was aware that the majority of the objections received had now been withdrawn as a result of conversations had between the applicant and their neighbours but stated that she felt it was a pity that they had seemingly not been notified of these plans until quite late in the process. She questioned whether they were aware of the things that had been reported to the meeting today in terms of the consideration of other locations. She went on to comment on the hours of operation for the plant noting that it was proposed that this be operational from 07:00 and questioned whether it would be possible for the Hall to consider a 07:30 start instead to assist those living directly above this location. Giles Fagan, Clerk designate to the Stationers’ Company responded first to the point on hours of operation for the plant and stated that, realistically, this would not be in operation until 08:00 in the morning for the majority of the time. However, there were few occassions where the Hall played host to an early breakfast meeting which commenced at 08:00 and, in order to adequately heat or cool the space being used prior to this, the plant would need to be operational from 07:00. Mr Fagan added that, ideally, this would be from 06:30 for such occassions but that a compromise of 07:00 had been reached. With regard to consultation, Mr Fagan recognised, in hindsight, that this could have been raised at an earlier stage with the Hall’s neighbouring residents but reported that information had been sent by the contractors in October 2020 outlining the intention to carry out these works but no response had been received until late December 2020 when the objections began to come in. The Member thanked Mr Fagan for his response but suggested that those who would be most adversely affected by the plans ought to have been notified of them at an earlier stage in the process and before a finallocation had been decided upon.

Another Member followed up on the point made around hours of operation and stated that she was very conscious of the golden rule around 8 hours and sleep hygiene. She noted that the hours mentioned within the report (23:30-07:00) for which the plant would not be operational equated to less than 8 hours and questioned whether the applicant would be amenable to ensuring that, when early morning meetings were taking place and the plant was required to be operational from 07:00, an 8 hour minimum window in which it wasn’t in use was always maintained, bearing in mind that they had reported that this did not occur frequently. Mr Ashley responded by commenting that the plant had been designed to he operate at 12 decibels below background noise and so the effect of the plant running during the night should not be perceptible to the residents or impact upon their sleep hygiene.

Another Member stated that he had personal experience of air source heat pumps and had found that they were normally extremely noisy. He noted that the applicant claimed that the plant would be 12 decibels below ambient noise but questioned what ambient noise levels had been taken into consideration given that it tended to vary significantly in the location in question. He sought reassurance from the applicant team that the ambient noise levels referred to also applied to the night time noise levels in this location. With regard to the hours of operation, the Member stated that, in licensing, there was a policy that dictated that residents were entitled to a good night’s sleep between 23:00-07:00 and that he did not therefore understand why a terminal hour of 23:30 was proposed in this case. Mr Ashley reported that the Hall had engaged a specialist acoustic firm called Ion Acoustics to advise on these plans alongside the engineers designing the plant. He introduced David O’Neill of Ion Acoustics and asked that he respond to the question on noise. Mr O’Neill welcomed the opportunity to clarify this point and reported that background noise levels had been measured over an extended period of time for full 24-hour periods with day, evening and night time levels measured separately. These were then compared not only with the ambient noise level which could vary with passing traffic and the like but also with the underlying, steady background noise emitted from the service plant of nearby buildings/offices and against which the noise limit had been set. He reported that the City’s noise limit was for plant to operate at 10 decibels below background noise levels which was actually the most onerous interpretation of the British Standard and guidance. Mr O’Neill reiterated that these plans set the plant operation at 12 decibels below background noise which was a reflection of how well the plant had been designed. It was highlighted that this would be at the worst affected window with noise levels dropping off further against the background level elsewhere during daytime and also throughout the night. Mr O’Neill added that, from a noise point of view, it would normally be argued that the plant could operate for 24 hours a day and that a terminal our of 23:00 could not be based on any noise disturbance.

Another Member questioned when noise levels had been measured given that levels in the City were currently extraordinarily low due to the ongoing pandemic and national lockdown measures. She went on to state that the key issue here was around vibrations and the noise and disturbance that there could cause. It would also be essential to ensure that the units were well maintained with ambience levels set and monitored regularly and she questioned whether there was a condition proposed to ensure that ongoing maintenance took place. Mr O’Neill reported that noise levels had been measured in 2019, before the pandemic took hold and therefore in more typical conditions. With regard to vibration, Mr O’Neill reported that the units would be installed on dedicated, specific anti-vibration mounts within the proposed enclosure which was also a requirement set out within the draft conditions. Immediately below the plant was Stationers’ Hall so there was no third party underneath the proposed location. With regard to maintenance, Mr Ashley recognised that ageing air conditioning units could become rattly but assured the Committee that there was a condition within the Officer’s draft recommendations requiring that the plant be maintained and replaced in whole or in part as often as was required to ensure compliance with noise levels. The Member went on to question whether, in practical terms, the units would be serviced annually. Barry Peebles of Method Consulting who had designed the plant commented that, in line with the warranty, regular maintenance would need to be carried out. Mr Fagan added that regular maintenance of all equipment in the Hall took place and that, as keepers of the Hall, this would continue to be treated as a priority.

Seeing no further questions of the applicant team, the Chair asked that Members move to any questions they might have of Officers and to the general debate.

A Member noted that the report referred to the fact that any new plant would be required to emit noise lower than the existing noise level by at least 10 decibels and questioned whether Officers could inform the Committee what this would equate to in either percentage or fraction terms. Officers responded to state that it was difficult to respond in percentage terms as decibels were a logarithmic scale and that, in actual fact, a very large reduction was required and was therefore a challenge to achieve. They went on to state that what was present at the moment in terms of noise levels approximated to around 50 decibels and that, as the acoustic expert had explained, these were background noise levels that were present for 90% of the time during both the day and night.  The City required that the noise levels emitted from new plant be 10 decibels lower than these, already present, background noise levels and that this should not therefore be disturbing to sleep and be virtually imperceptible to those in nearby dwellings in most circumstances. The Member responded to state that he was aware that 10 decibels lower equated to 1/10^th of the ambient noise and should not therefore be audible. A lowering of 12 decibels would equate to approximately 1/15^th of the background noise. The Member stated that he was therefore of the view that condition 4 around the hours of operation was almost unnecessary and that he had intended to propose an amendment but could see that some had now withdrawn their objections to the application on the basis that this condition existed. He concluded by stating that he could see no possible reason for refusing this application and that he would be supporting it.

By way of a follow up, another Member stated whether it was correct to therefore conclude that, aside from times where residents were going to sleep or waking up, the noise from the plant would be mostly imperceptible but would be a slightly perceived noise issue to those who perhaps did not sleep well throughout the night. She questioned once more why there could not be a condition requiring an 8 hour pause in the operation of the plant each day which would then counteract the issue of the slightly perceived noise for some. Officers responded further to clarify that, whilst they had said that the noise may be perceptible, the nature of the noise emitted from these units, at ten decibels below the background noise levels, should be inaudible. However, it was recognised that this was a very varied test. It was also recognised that sleep disturbance was most prevalent when people were trying to go off to sleep and when they were just about to wake up. With regard to the hours of operation, it was reported that the reason that the additional 30 minutes until 23:30 was required according to the operational need of the plant to ensure that it could condition the building as required for use.

The Interim Chief Planning Officer and Development Director highlighted that condition 4 states that the plant should not be operated between the hours of 23:30-07:00 and that it was understood that these hours were proposed because of the nature of the uses within the Hall’s event spaces and to capture the eventuality of these spaces being used for early morning meetings as well as for evening events.

Another Member highlighted that this Committee were always very concerned with the protection and maintenance of the City’s heritage and stated that he felt that the positioning of the plant would do just this in the context of Stationers’ Hall. He went on to comment that he understood the importance of having this having visited the Hall on several occasions and added that he was of the view that the application struck the right balance in terms of local residents and the potential effect on those in the Gallery.

Another Member sought further clarity on the hours of operation, stating that she understood that the units would be operational whilst the hall was in use to regulate the temperature inside the building and also to protect the heritage assets. She questioned whether when the Hall was not in use (at weekends or at the present time for example) the units would therefore be off. The Interim Chief Planning Officer and Development Director confirmed that the requirement for the units was two-fold and that this also concerned the protection of the historic fabric of the building.

A Member stated that it was important to put the issues being raised into perspective and underlined that, in his personal experience, noise from such plant was imperceptible. He went on to talk about air source heat pumps and the City’s Climate Action Strategy which sought to encourage people to do things that would render buildings more environmentally friendly in the future. He was of the view that the installation of such plant should therefore be encouraged.

Another Member spoke to endorse this point but went on to pose a further question regarding noise. He stated that, as he understood it, the noises referred to were an average and that the main issue with noise emissions from such plant tended to be centred around the start up and run down noise as opposed to the general running. With this in mind, the issue around the additional 30 minutes proposed for nighttime operation was pertinent in terms of noise nuisance to neighbours. Officers responded to reiterate that the hours of operation for this particular plant were to be restricted as set out and that, as such, start-up noise should not be so stark. They added that they thought that any start-up noise with this sort of plant was now much more controlled with multiple units ramping up individually as opposed to all at once. It was added that these noises should also not be an issue with well maintained plant as they often became more pronounced as plant became worn and aged die to additional vibration. Officers concluded that the plant noise emissions had been assessed based on the plant running on full and that the Committee had therefore been informed of the worst case scenario here.

The Committee then proceeded to vote on the recommendations before them within this report. The vote was conducted by rollcall led by the Town Clerk with those Members present and eligible to vote asked to also confirm that they had been present for and able to hear the entirety of this item.

Votes were cast as follows:    IN FAVOUR –  27 Votes

                                                OPPOSED –   0 Votes.

There were no abstentions.

RESOLVED – That planning permission be GRANTED for the above proposal in accordance with the details set out in the attached schedule.