Sustainably restoring Brockwell Hall: Lambeth’s investment in Brockwell heritage

The hall has been updated with new lighting and air ventilation systems, as well as better insulation and windows, to bring it into the 21st century. 

A new ground source heat pump was installed in the surrounding grounds to provide heating and hot water for the hall, the new event space, and adjoining offices. 

The Challenge

Brockwell Hall, a Grade II* listed manor house, has been the heart of Brockwell Park since 1813. It was originally built as a residence for John Blades, a wealthy, internationally renowned glass and chandelier maker. After Blades’ death, the estate, including the Hall, passed to his family and when one of his descendants decided to sell it, a public campaign, led by Sir Thomas Lynn Bristowe, MP was launched to secure funds from the London County Council (LCC) and other contributions to purchase the site for the creation of a new public park. The LCC bought the Hall and part of the estate, which formally opened as Brockwell Park in 1892. Then, it purchased further plots of surrounding land until Brockwell Park was created within its current boundaries and opened in 1903. The Hall has since been managed and owned by the LCC and then by Lambeth Council.

For the last couple of years, before it was closed for refurbishment, the building was used as a café, council offices and park maintenance depot; most of the building and site were largely underused, undiscovered and unappreciated.

In March 2021, the National Heritage Lottery Fund (NHLF) awarded Lambeth Council nearly £4 million to restore Brockwell Hall. These costs include capital, revenue, and non-cash elements, in line with NLHF requirements. Lambeth Council also secured £429,000 from the Department of Energy Security and Net Zero (DESNEZ) Public Sector Decarbonisation Fund in February 2021 to install a ground source heat pump to provide all the heating and hot water for the Hall, the new events space and the adjacent buildings.

Brockwell Hall before the restoration

Action Taken

Ground Source Heat Pump

A ground source heat pump (GSHP) was chosen to provide heating and hot water for the hall, the new event space, and the additional office space in the refurbished stables.

The GSHP is connected to pipes in 28 boreholes drilled 120m deep. Brine or saltwater flows through these pipes, and heat is exchanged between the ambient warmth of the soil and the cool brine liquid, circulating the heat back into compressors in the plant room underneath the hall.

The borehole method was chosen because deep drilling can create a much greater contact area than horizontal pipework under the soil. It also ensured that construction avoided any impact on tree roots within the conservation area. This means far less area of the park is needed to generate the same amount of energy as an equivalent horizontal piped system. 

Drilling the bore holes and the new plant room to house the GSHP tanks and equipment

When designed correctly, GSHPs work well in older and listed buildings, but the fabric of the building needs to be of a high standard, ensuring it is ventilated correctly and has sufficient insulation to reduce heat loss. Some of the measures installed on Brockwell Hall included:

• Reducing air leakage through fireplaces
• Reducing air leakage through air bricks by replacing the air movement with a carefully designed heat recovery system.
• Improving insulation in the roof voids.
• Improving window glazing where possible within the constraints of conservation orders.
• Ensure sash windows are refurbished and adequately maintained to allow for quick ventilation during events when the rooms are at high capacity.

The refurbishment also includes new intelligent absence detectors to switch off lights in only occasionally occupied rooms, such as toilets, storerooms, and back-of-house areas. This is particularly helpful in a building with multiple types of users, where behaviour change isn’t as easy to achieve.

New event space

The new event space was constructed on the side of Brockwell Hall into the old Stable Yard. It will host a wide range of events, such as weddings, conferences, away days, and meetings, and has been designed to the highest sustainability specifications.

The extension has high insulation and airtightness to reduce heat loss in the winter, but it also uses passive ventilation via high- and low-level windows to circulate air during the hotter summer months. Heat recovery systems are used in the adjacent kitchen areas, with intelligent LED lighting throughout. The building consumes 20% less energy than the standard requirement for meeting building regulations. 

The new event space and renovation event rooms inside Brockwell Hall

The Results

The refurbishment was finished in spring 2025, with the building opening to the public in May 2025.

Carbon Savings 

The total energy savings are expected to be 221,076 kWh per year, with gas savings of 280,927 kWh/yr and an increase in electricity consumption of 59,851kWh/yr, leading to a 75% cut in energy consumption. This will lead to carbon emission savings of 46.52 tCO2e and annual energy cost savings of £4,200 for heating and hot water compared to the previous usage in the building.

Gas use has been completely phased out of the building, with electric cookers installed for catering facilities.

The main structure of the new space was made from mass timber, specially engineered wood to be as strong, durable and versatile as concrete and metal, but much more sustainable. Using this reduces the embodied carbon of the extension.

Operational emissions are reduced through the passive design for natural ventilation, high efficiency windows and lighting, and the GSHP providing low-carbon heat.

Learnings from Lambeth Council

Historic, listed buildings present challenges regarding switching to low-carbon energy and heating, with the need to strike a delicate balance between conservation and carbon emissions. This project has demonstrated that it is possible to overcome these hurdles, with the restoration and decarbonisation of Brockwell Hall as a showcase example that will provide valuable lessons for custodians of heritage assets throughout the UK.

The restoration has led to increased usage of the buildings so that they can be better utilised for events, office space, catering and private hire. By including energy efficiency measures and decarbonisation, this increase in use could have led to an increase in energy consumption and carbon emissions, but incorporating sustainability throughout ensures that consumption and emissions are kept to a minimum despite the increase in occupancy.

Challenges

• Access to national grid upgrades was needed to embed the new GSHP system. Early engagement with the District Network Operator (DNO) is key to avoiding later costs and delays.
• Early engagement with a Measurement and Verification (M&V) expert is key to collecting, analysing, and visualising energy and emission data.

Learnings from Brookbanks

Brookbanks undertook the Mechanical, Electrical & Public Health designs and site supervision for this prestigious project, working closely with Pringle Richards Sharratt Architects to deliver a high-quality refurbishment of the existing Brockwell Hall, Stables and new Events space. There were several potential challenges to the project, and the key learning and reflection from this are noted as follows:

• Adopting a fabric-first approach to upgrading the insulation at Brockwell Hall was always going to be challenging because of the listed building status and heritage planning restrictions.
• Limited fabric upgrades could be implemented, and opportunities were seized to reduce energy consumption where appropriate. This helped ensure the building's long-term preservation by maintaining adequate ventilation.
• Utilising passive design techniques that leverage the building’s thermal mass and original features enabled further sustainability benefits that complemented the listed status.
• Successful refurbishments require a high level of coordination and specialised knowledge of working within heritage buildings. Brookbanks and Pringle Richards Sharratt Architects have extensive experience with public building projects and have refined sensitive renovation techniques.
• Understanding the Public Sector Decarbonisation Scheme's specific needs and eligibility criteria, along with precise calculations to support grant applications, was vital in securing funding. It was particularly important for a large project to be able to use the funds within a short timeframe.
• Obtaining a quality contractor, G-Core, for the Ground Source Heat Pump system was crucial. G-Core understood the physical challenges of installing 120m deep boreholes in a live public park and the technical requirements for the system to provide heating and hot water to Brockwell Hall.

Brookbanks is proud to have supported Lambeth Borough Council in providing a quality refurbishment for the benefit of the local community and a new lease of life to this historic building in collaboration with Pringle Richards Sharratt Architects and G-Core. In undertaking the Mechanical, Electrical & Public Health designs and site supervision for this scheme, we have managed to realise a fully modern upgrade whilst maintaining the full character of Brockwell Hall and achieving a significant decarbonisation of one of the Council’s major building assets. The clever use of appropriate technologies and an experienced team has ensured the sustainable long-term preservation of this public building for generations to come.