Photo of the outside of Gas Retort House at night
Gas Retort House © Philip King & Church of England Birmingham
Gas Retort House © Philip King & Church of England Birmingham

Former Gas Retort House Recycled into Church

Birmingham’s ‘Former Gas Retort House’ was built in 1822 for the Birmingham Gas Light and Coke Company to contain the risky, high-temperature process of producing gas by heating coal.

This Grade II* listed building has a distinctive fireproof iron roof with cast iron trusses and wrought iron tie rods. In recent years, this building – once integral to the supply of town gas to nearby streets – has been effectively recycled into a church.

When the gas works closed in 1850, the building became obsolete. Historic maps show us that the building was reused as a warehouse in subsequent years, but its historic significance was unrecognised until 1992 when, during a proposed redevelopment of the area, its unusual roof design was noticed by the city planning department.

Unused and 'at risk'

The building stood vacant in 1993 when it was listed on the National Heritage List for England. When it was still unoccupied in 1998, we added it to our Heritage at Risk Register because when historic buildings are left unused, the risks of decay or damage by illegal occupation or arson greatly increase.

That year, a recording and analysis project by the Birmingham University Field Archaeology Unit found that the building had been substantially altered over time. Original openings had been blocked up and new, rectangular ones had been created unsympathetically. Supports for substantial timber beams had been installed to support heavy loads (for an unknown industrial purpose). The survey also found that sympathetic treatment could return the retort house to its original form.

In 2000, the building was part-renovated for commercial office, leisure or workshop use. Although at that time the building was in good condition, it remained vacant and was at risk of falling into disrepair if a long-term occupant could not be found.

Occupying a historic building and regularly maintaining it is very important. If allowed to rapidly decline, vacant historic buildings can, in extreme cases, become dangerous and demolition may be the safest option.

When a building is demolished, the embodied carbon in its materials is lost, whilst the process of demolishing and transporting waste also generates carbon emissions and waste. Reusing and recycling our historic buildings, instead of demolishing and building new, is good for the environment.

How ‘meanwhile’ projects helped

If a historic building becomes vacant, the introduction of interim ‘meanwhile’ projects can pre-empt many of the anticipated risks and highlight the building to potential long-term occupiers as a vibrant, viable site for long-term use.

In this case, the retort house was occupied by several interim projects, including periods as a film set and performance art venue, until a permanent occupier could be found.

Recycling, refurbishment and reuse

Industrial buildings sometimes present particular challenges. The physical form of some can make them difficult to adapt to new uses. In other cases, adaptation for reuse could destroy features integral to the building’s historic significance.

In 2011, Historic England published research on historic industrial buildings at risk across the country. Our research found that 10.6% of industrial Grade I and II* listed buildings were at risk, a percentage three times higher than the national average for Grade I and II* listed structures.

Fortunately, in the case of the retort house, the building’s form and location made it amenable to reuse. Illustrating the attractive versatility of many historic industrial buildings, multiple uses were considered for the space, including a gym and crèche. Ultimately The Church of England bought the site and gave it a permanent function as St Luke’s Gas Street church.

APEC Architects completed work to sensitively retrofit the structure and make it fit for its new purpose. Several measures were considered to improve the building’s thermal performance. Insulated roof panels had been installed during the work completed in 2000. The option of adding further insulation was investigated but dismissed as they could have an impact on the historically significant roof trusses.

Steel secondary windows were installed behind the surviving glazing, and new aluminium double glazing units were fitted in the previously boarded-up ventilation arches to allow light back into the space.

Insulation of the walls was considered, but instead insulated raised timber floors were installed throughout, and air source heat pumps now heat and cool the space. To accommodate the features that a modern church needs (toilets, a kitchen and a plant area), freestanding insulated pods were constructed in elm, a renewable product with negative embodied emissions.

In this way, an irreplaceable component of Birmingham’s industrial heritage has been preserved through retrofitting and the building’s fabric has been effectively recycled, whilst a new use has given it a new lease of life.