The structural elements of the complex fully meet UNESCO World Heritage criteria (ii) and (iii) for the site's outstanding universal value. The conservation masterplan's “object book 3” recommended both buildings be “preserved with exemplary equipment”. According to this masterplan, functional correlations were to be preserved in one section, exemplified by the corresponding machinery. 
Both buildings are reinforced concrete constructions with brick facades. The first floor of the extraction and compressor hall is spacious, with ceiling heights of about 16 metres. A series of parallel steel beams span the building's short side and rest on reinforced concrete pillars at the external walls, integrating crane runway corbels. The hall is illuminated by three high, slender, rectangular windows in the gables, horizontal rectangular windows above the crane runways, and glazed roof lanterns along the central axis. 
The main task of the industrial plant and machinery was to compress the gas produced during coking, which was partly used to generate electricity. 
The conversion concept for the building provides two major benefits: 
1) The hall on the first floor could be preserved in its entirety, in its original dimensions, and without the use of any partitions. In addition to preserving the original walls, crane runway, control panels, gas pressure apparatus, lamps, and exemplary compressors and exhaust systems, the original architectural concept continues to gain in value.
2) About half of the ground floor, including all machinery, equipment, and pipes, was enclosed behind glass — also encapsulating remnants of the chemical processes that remain dangerous for humans. This kind of “time capsule” enables full, in situ conservation of the historical elements. 
Furthermore, on the ground floor, the surfaces of the concrete pillars were conserved, including their historical lesions or scratches. 
The machinery to be preserved on the first floor was selected in the peripheral areas, so that the central area was freed for reuse. The requirement for year-round usability resulted in thermal enhancement through adding an underfloor heating system. In the newly paved floor, tiles of differing colours show the places where machines were once located. The specific reuse concept applied consistent principles to all usable areas: minimal intervention while aiming to achieve energy savings and upgrade basic thermal comfort. The installation of underfloor heating, for example, avoided the need for internal or external insulation, thereby averting destruction of the original wall surfaces.

The Grand Hall contributes to the revitalisation and attraction of the former Zollverein industrial area. Since the Ruhr region lacked a venue of this capacity, the Grand Hall targets regional or supra-regional clients rather than local events. Nevertheless, different units can also be booked individually: from 40 sqm up to the total area. While the ground floor is densely built-up with pillars (the glass case in particular is fully packed), the first floor, now cleared, offers free and flexible space. The venue can host concerts, exhibitions, and trade fairs with up to 2,500 standing places or 1,500 seats. As the smaller unit, the ground floor can host club events as well as conferences with up to 800 guests. The former electricity distribution station offers an extremely wide range of uses: Flexible partition walls are pre-installed so that up to ten additional rooms can be configured for workshops, seminars, presentations, or meetings, or else used as a large area for a separate event. The venue offers a complete service package: from catering and trade fair construction to lighting; from conference conception and organisation to technology and shuttle service.
The building benefits from double accessibility: at the front is the foyer preceded by a vestibule, while equipment and materials are delivered to the ground floor truck entrance which has a freight elevator with 5-tonnes capacity. 

The decision in favour of the conversion was mainly made by the former owner RAG Montan Immobilien, conservationists, mining authorities, prospective investors, and the present owner Zollverein Foundation. Information was disseminated locally, regionally, and nationally through various media. The location can be rented by local communities, although a mismatch might exist between local needs and the facilities on offer.

By reusing existing structures and thus saving the embodied energy associated with the original construction, the project generally contributes to sustainability. In addition, encapsulating the areas housing the major machinery prevents public access to contaminated or potentially hazardous areas and reduces the risk of residual contaminants spreading.
The conversion of the Grand Hall mainly meets two of the UN SDGs (sustainable development goals): 
1. Decent work and economic growth: A number of companies provide services for events, such as furnishing, technical equipment, stage construction, and catering, some of which are based at Zollverein, in Essen, or in the wider area. This provides employment opportunities and thus contributes to inclusive social and economic development at a small scale.
2. Sustainable cities and communities: The revitalisation contributes to greater urban density at Zollverein and helps to avoid urban sprawl. This could contribute to reducing CO2 concentrations at both regional and global levels, to less land-sealing, and to more environmentally friendly buildings.

Information about the project was disseminated through a diverse range of magazines and the Grand Hall's marketing efforts. The Denkmalpfad Zollverein guided tours of the coking plant site run along the outside of the Grand Hall and focus, among other things, on historical industrial processes. 
Main event programmes often include a supplementary guided tour of Denkmalpfad Zollverein, in which the cooperation of former miners has proved particularly successful. Participants in such events may also serve as multipliers of the information gained on-site.

For Zollverein, the Grand Hall is regarded as a milestone for the structural development and economic revival of the area. This primarily derives, on the one hand, from its location in the centre of the coking plant site, and on the other hand from the type of reuse. Thus, the Grand Hall is regarded as a catalyst and multiplier for the further development of the coking plant and the entire World Heritage Site.
The new venue immediately gained a reputation not only for the industrial flair of the location and the flexible use options, but also for its professional lighting concepts. In 2016, the Grand Hall was among the three finalists in the “Newcomer Location” category for the Location Award, which is regarded as the national quality seal for event locations. In 2017 the Zollverein UNESCO World Heritage Site won the Location Award for “Cultural Locations for Events”, beating more than 40 other contenders in the category; and won the audience award for the best film submitted. The Grand Hall has also attracted international guests, including a two-day conference on “digital transformation” with 500 delegates from the EU Commission in Brussels. Regionally, the Grand Hall is regarded as the primary venue for events. 
A number of partners, mainly based in the Ruhr region, are involved in organising and managing events, thereby providing job opportunities, although on a small scale and requiring specific skills.

Basic research was conducted on the machinery present prior to the conservation and reuse, as documented and evaluated via visual documentation, description, and discussion with conservationists, architects, and former workers with specific knowledge of the machinery and industrial construction. Photo-documentation of the buildings and technical installations was compiled within the conservation masterplan's “object books”. 

Private investment in the building is the result of long-term involvement in the site and represents thus an endogenous development, a development from within the Zollverein site. The investor Claus Dürscheidt was known for many years as the investor and owner of the “Casino” restaurant and event location at Zollverein and elsewhere in the Ruhr region. For the conversion of the Grand Hall, he personally acquired the group of investors, which acts as both developer and operator under the name “Grand Hall GmbH”.
The entire development process can be structured into three main phases:
1. The conservation masterplan assessment, conducted in 2002, categorised the extraction and compressor hall as “to be preserved with exemplary equipment”, thereby forming a framework for future conversion concepts. Concurrently, according to the (urban) masterplan, a large event venue was to be built at another Zollverein site (north of the coke oven battery, near the railway tracks) as one of the concept's “attractors”.
2. The high level of on-site contamination led to a long process of seeking appropriate forms of reuse and corresponding investors. Under the guidance of the Zollverein Foundation, all stakeholders agreed on an operating plan developed for the conversion, which regulates the harmful substances and future uses. As a result, the former owner RAG Montan Immobilien was able to pass on its decontamination obligations via the Zollverein Foundation to the privately funded developer/investor group.
3. Grand Hall GmbH is both the investor and developer, and conducted the project together with a team of specialists in heritage conservation. HWR Ramsfjell (architects) and “Die Schmiede” (restoration) ran the restoration and conversion project from 2014 to 2017. Diverse planning instruments were used in the transformation process: listing of historic objects, environmental impact assessment, conclusion of a leasehold contract, and a formal planning process with a legally binding land-use plan (Bebauungsplan).

Core resources, such as visual integrity and authenticity, were preserved. New resources are activated through reuse: Regional and national events might increase the supra-regional attractiveness of Zollverein and the Ruhr region.