Halifax Town Hall Planning & Heritage Statement Proposed Installation of Air Source Heat Pump, Roof Insulation & Replacement Roof Glazing 1. Building History & Significance Halifax Town Hall is a grade II* listed, 19th century town hall of Halifax, West Yorkshire. It is notable for its design and interiors by Charles Barry and his son, Edward Middleton Barry, and for its sculptures by John Thomas. The Mayor and corporation first proposed that they build a new town hall in 1847. They suggested it again in 1853 after the town had become a borough five years earlier but they still had no central offices. They proposed it again in 1856. The later proposals were prompted by the 1853 Improvement Act, which allowed the borough to borrow £15,000 to build a town hall, Courthouse and police station. The 1856 proposal was also prompted by John Crossley, who was at that time developing Princess Street and Crossley Street, using the architects Lockwood and Mawson who later designed Bradford City Hall. This may explain why the town hall blends in with several Crossley Street buildings, which are now listed as a group. The council, Edward Akroyd and John Crossley requested that Charles Barry judge the design entries; he disliked all three entries and was asked in turn to submit his own design. His design was accepted, but he died in 1860. His son, Edward Middleton Barry, completed the design which was erected on a 148 x 90 ft plot on John Crossley's land. The foundation stone was laid in 1861. Whiteley Brothers were the builders. It was listed on 31 July 1963. Premises Description The building is detached and built of sandstone in the classical style, with a tower and steeple at the corner. There is a rusticated basement and two storeys above with arcades, columns and arches. Around the top of the walls there is a balustrade with finials. There is a metal roof with skylights. The steeple is 180 feet high, metal-capped and decorated by John Thomas with statues representing the four continents. The entrance has a porch with an arch and balustrade with ball finials. The other entrances on the west side have old iron lamp standards and new lanterns, and one has an iron balustrade. This building should be understood in the context of the whole group of buildings in Crossley Street, which are all listed. 24,000 tons of local Ringby sandstone from Swales Moor was used for the building. The portico has the old Halifax coat of arms over its arches, with the heads of Wisdom, Justice and Mercy.[1] Tower and spire This structure is 180 ft high, with a carved tile-effect on the spire. The four continent statues by John Thomas are as follows. Africa faces away from Crossley Street and consists of an ancient Egyptian and two boys. North America, above the tower portico, is a Native American with two small figures holding a paddle and a roll of tobacco. Europe, at the front of the tower in Crossley Street, has emblems of civilisation and refinement. After sculpting these, John Thomas died, and Asia was carved under the supervision of Daniel Maclise. Asia faces down Crossley Street, on the opposite side of the tower from the portico, and is a figure with a Chinese boy and tea chest and a child with flowers. On the corners of the spire are four seven-foot angels. Roof The outer, visible sections of roof are formed by large slate slabs that give the appearance of a mansard arrangement. Whereas the inner sections of roof are of traditional blue slate on battens. The roofs above the council chamber and Victoria Hall are formed with patent glazing systems incorporating cast Georgian wired glass panels. The patent glazing bars and glazing above the council chamber are modern, replacing a non-original and failing system in 2014. The patent glazing system above the Victoria hall is unlikely to be original due to the glass sizes employed in the current system. It is more likely that this system dates to the early 1900’s as wired glass and glazing systems developed in the late 1890’s 2. The future The building still forms the Political and administrative hub of the Borough Council of Calderdale. With office and function accommodation on the ground and first floors with ancillary accommodation and servicing in the basement. There is a large attic space above the perimeter of the building. Proposals are being drawn up to improve access and occupancy within the building to ensure that the asset is fully utilised. The Council as owners of the building declared a Climate Emergency in 2019 establishing a commitment to drive towards being carbon neutral by 2038. In October 2020 Central Government announced a Public Sector De-carbonisation fund. This is to provide grant funding to remove carbon based (coal, oil & gas) heat sources from public sector buildings and replace them with low or zero carbon alternatives. In addition to funding new technologies, monies are available for fabric improvements to reduce heat loss and improve thermal efficiency. The works proposed in this scheme will endeavour to significantly reduce carbon usage and vastly improve thermal performance. Consultations have been made with Conservation Officers in order to find the most appropriate heat pump solution whilst minimising harm to the historic building assets. 3. Proposals Halifax Town Hall currently has two boiler houses that serve the building on a 60:40 ratio. The north plant room (smaller of the two) serves 40% of the accommodation. It is proposed that the existing gas fired heating boiler in this plant room is removed and replaced with an Air Source Heat Pump. The installation will comprise a heat exchanger and control system located in the current boiler room and a heat pump located at roof level. An air source heat pump works on the following basic principles. Heat from the air is absorbed at low temperature into a fluid. This fluid passes through a compressor, increasing the temperature, and transfers that higher temperature heat to the heating and hot water circuits of the building. Because of the buildings construction it has a large thermal mass which means once in the building heat is retained for a significant amount of time. The nature of the air source heat pump means it can be running all the time ensuring a steady delivery of heat and maintaining the building fabric and its contents at a steady temperature The existing cast iron radiators and pipe coils within the building provide ideal heat emitters for the lower temperature water obtained from the heat pump. Therefore, at present there is no need to look at wholesale replacement of the existing distribution and emitter system. It is proposed that a new plant platform be constructed on the inner roof slope of the eastern elevation. This will be formed by extending existing steelwork located in the attic space through the roof slope and then creating the platform from that level. The platform will be positioned so that all the plant sits below the ridge line and will big enough to allow access for maintenance and additional plant in the future. This location is the only feasible position to locate the heat pump ensuring minimal harm to the building. The slope of the roof is shallow enough to provide enough width for the platform whilst ensuring that the unit remains below the ridge line of the roof. Initially there will only be one air source heat pump unit provided on the platform. However, to ensure that the proposals are future proofed it is proposed that the platform is appropriately sized to ensure a further 2 units can be positioned on the platform which will allow the south plant room to be replaced. At present, in its original state, the Town Hall does not have any insulation in the roof space and the glass roof areas are single glazed. This lack of heat retention means that any heat generated in the building is quickly lost through the roof. As well as funding the heat pumps further grant has been sought to insulate the slated sections of roof and re-glaze the patent glazing areas with thin section double glazing. It is intended that the glazing bars will remain in situ on both glass roof areas with only the single glazing being replaced with double glazed units. Insulating the slated roof sections alone will result in a minimum of 80% reduction in heat loss. In its current state the roof has an average U-value of 3.78 W/m2 K. Following the insulation and re-glazing works the anticipated U-value will be around 0.37W/m2 K. This is a significant improvement and will ensure heat put into the building will remain there for longer and therefore reducing heating demand and CO2 emissions. 4. Justification Whilst the project aims to minimise harm, the provision of an air source heat pump system to replace 40% of the existing gas boiler capacity will cause less than substantial harm to the existing building, at the lower end of the scale. The proposed location of the heat pump will mean that it can not been seen from ground level or any of the nearby buildings, therefore preserving the visual aesthetic. The platform required to site the plant will be sized to allow installation of further heat pumps, possibly 2, in the future once the main boiler house has reached the end of its economic life in the next 10 to 15 years. The pipework connections to a from the existing basement boiler room and the new rooftop plant area will be routed as discretely as possible including utilising the existing flue / chimney which links the roof directly with the basement plant room.