Local authorities are racing to hit their net zero emission goals, and existing building stock will be central to meeting ambitious targets. Glasgow has pledged to become one of Europe’s most sustainable cities and is aiming to reach net zero by 2030. Glasgow’s largest park, Pollok Country Park, and its many historic buildings have been a key part of Glasgow City Council’s eco-efforts. Green tech firm IES has created a live digital twin to identify how and where energy is being used across the estate.

The goal is to take Pollok Country Park off-grid so that the park can be fuelled by locally derived energy – to a large extent. The stakes are high as the park spans 146 hectares and is a huge visitor attraction boasting several historic properties. To decarbonise Pollok Country Park, the local council sought to find out which renewable energy sources would be the most efficient and cost-effective to implement.

The many historic elements of Pollok House, a Georgian building constructed in 1752, need to be taken into account while exploring decarbonisation options. Any changes made to improve the energy efficiency of the building have to be respectful of the architecture and integrity of the Grade A listed building. However, the property has high heating requirements due to its old stone walls, which have also been responsible for problems with damp and condensation.

Pollok Country Park is also home to the Burrell Collection museum which houses thousands of historic artworks and objects. The Burrell Collection re-opened to the public in March 2022 after a renovation project, and the site has been visited by more than half a million people since. The museum has a large floor area with very specific cooling and dehumidification requirements to protect exhibits. The art gallery also has its own specific energy needs.

Other buildings across the park include the Stables Courtyard buildings, Knowehead Lodge and the Police Dog Pound. Some of these buildings are still in use today, with Knowehead Lodge, a former staff quarters for those who worked on the estate, being used as an office for park management staff. The Old Stable Courtyard is also being transformed with a sizeable government grant to become a Living Heritage Centre. From an energy perspective, the Burrell Collection accounts for 69% of energy used across the estate, followed by Pollok House (22%), the Police Dog Pound (6%), Knowehead Lodge (2%) and the Courtyard (1%).

Every aspect of the park and its infrastructure has been mapped out by the IES digital twin. Since its implementation, this living model has maximised the use of the city’s green and blue infrastructure to mitigate emissions across the estate. The digital twin is being used to inform energy network modelling, with the goal of making Pollok Country Park energy independent.

As with any carbon reduction project that spans a large area, IES took a phased approach when identifying the optimum means to improve the site.

Using the digital twin to model future scenarios, IES found that Pollok Country Park could reach net zero carbon emissions by implementing a multi-aspect energy network.

The Burrell Collection 
In the early stages of the project, a baseline digital twin was created of the estate which highlighted where energy was being used. This technology also measured the total energy consumption across the park. The impact of different improvement measures were then modelled, demonstrating how much of an impact each would have on carbon output.

This scenario modelling determined what potential outcomes could arise from each intervention, the impact it could have on reducing the estate’s carbon footprint and the most cost-effective method. Modelling showed that planned improvements to the park’s buildings could reduce carbon emissions by up to 34%.

Thermal performance improvements are at the heart of interventions for the Burrell Collection building. This iconic museum is responsible for the majority of Pollok Country Park’s emissions, and its carbon footprint due to energy consumption stood at about 368 tonnes. As the only building in the park to have a mechanical ventilation system instead of a natural one, the museum needed a unique set of interventions.

Digital view of the Burrell Collection museum
Photo: IES

The refurbishment of the Burrell Collection has already had a positive impact on the sustainability of the museum, providing a 33.9% reduction in natural gas consumption of the building, primarily by reducing space heating demands.

Fabric and lighting improvements have also contributed to a total of 25% energy saving. High-performance LEDs were installed which, combined with the addition of condensing gas boilers, has made a major impact on overall carbon emissions of this important cultural site. A photovoltaic (PV) array was also installed on the roof as part of the project. Adding more PV panels was found to be a more effective way of meeting the Burrell Collection’s electricity needs than installing a wind turbine, which may also have required planning permission.

Installation of heat pumps was also rejected as it would increase electrical demand. In order to fully decarbonise the building’s electricity, it was determined that about 3,000m² of extra PV panels would be required, in addition to increasing battery storage from 1.856 MWh to 3.2 MWh.

Pollok House 
Interventions to Pollok House reduced the total carbon emissions to 115 tonnes from 165 tonnes. Due to the restrictions on Pollok House as a Grade A listed building, some standard interventions had to be avoided, such as double glazing and wall insulation.

But viable solutions were highlighted, including low-energy LEDs and high-efficiency condensing gas boilers. The impact of these interventions was significant. The low-energy LEDs and the decision that no electrical heating would be used post-upgrades, contributed to a 51% reduction in total electricity consumption. Overall, the improvements contributed to a 30% reduction in the building’s total carbon emissions.

Other solutions considered for Pollok House included modelling the option of heating demands being electrified using a ground source heat pump. The option of linking Pollok House to the Courtyard energy network was also considered. To keep energy use carbon neutral, it was determined that PV provisions and battery storage would need to be increased significantly in this scenario.

Courtyard buildings 
Use of on-site renewables and storage were found to be the ideal solution to power the courtyard buildings, supplemented by the addition of PV panels. The digital twin project also paid homage to the park’s rich history by showcasing sustainable energy generation at the water mill. This involved re-installing a hydro-electric turbine generating electricity from the river to power the courtyard buildings. It is hoped that this hydro-electric source of renewable energy generation will educate visitors and local schools about the process.

The courtyard buildings – where the use of on-site renewables and storage were found to be the ideal solution
Photo: IES

Using the digital twin to model future scenarios, IES found that Pollok Country Park could reach net zero carbon emissions by implementing a multi-aspect energy network. Components of this network include battery storage, additional renewable sources, heat pumps, and interconnection between all the buildings’ heat and electrical networks. Individual heat and electricity networks were modelled using IES’ Intelligent Virtual Network tool (iVN).

A live dashboard has been created to display the project data and results. This allows the energy, carbon and cost results for each individual building to be viewed at a glance by those involved at Glasgow City Council and other key stakeholders.

Engaging the local community has also been a key part of the project. A dashboard designed for the public to understand the energy scheme will be located in the park to engage passers-by and the wider public with the project.

Reaching net zero 
Looking broadly, to reach net zero, local authorities must implement targeted, cost-effective measures that can reduce the greenhouse gases emitted by existing building stock as much as possible. When councils have pushed the limits of what is reasonably possible, they can explore offsetting remaining emissions to hit their targets.

As Pollok Country Park has shown, there is no one-size-fits-all approach to decarbonisation. Honing a strategy with several different components is of paramount importance. Now, local authorities must drive forward with plans if they are to make significant progress and hit their all-important net zero targets.