Llys Cadwyn, Pontypridd

Our flagship project in Wales, Llys Cadwyn is a stand-out jewel of regeneration in south Wales’ crown. Our multi-disciplinary engineering services were instrumental in creating this high-quality, ambitious development.

Llys Cadwyn development Pontypridd

Hydrock delivered this new build project that has completely transformed the prime gateway site for Pontypridd town centre, and provided vibrant new headquarters for Transport for Wales in one of three buildings.

In collaboration with architects Darnton B3, contractors Wilmott Dixon, project managers Rhomco and Rhondda Cynon Taf County Council, we delivered full multi-disciplinary engineering design services for the BREEAM Excellent-rated, mixed-use Llys Cadwyn scheme, previously known as the Taff Vale Redevelopment, and a new footbridge linking the development to Ynysangharad War Memorial park.

Once home to the former Taff Vale Shopping Centre precinct, the site, which sits at the gateway to the town centre, had lain derelict. This eye-catching development will now bring hundreds of jobs to the area, acting as something of a catalyst for the town’s redevelopment.

The £42m redevelopment includes three parallel buildings ranging from two to five storeys, with new public spaces between each, and a basement containing parking, servicing and storage linking all buildings together.

As well as providing office space for over 1,000 people, the development features a striking gateway building that acts as a community ‘hub’, including a library, gym, activity studio, café and customer contact point.

Award winner

Llys Cadwyn won the Transformation award at the Cardiff Property Awards 2020 and was also crowned Winner of Winners at the awards held in March 2021. The judges commented that the scheme had been a social catalyst for positive change delivering over 3,900 weeks of training and employment opportunities and over £8m of social value return on investment.

Engineering solutions

This redevelopment saw a number of technical challenges, requiring a truly collaborative multi-disciplinary approach.

The location of this highly constrained site provided challenges, as it is bordered by three roads and a river. Our M&E engineers discovered design solutions to relocate existing services and ensure all three buildings and basements are fully powered.

We undertook dynamic thermal model simulations in order to inform the architectural design and maximise the passive solar thermal benefits of the proposed development.

In addition to the implementation of passive techniques, a number of low energy technologies were installed on the scheme, including:

  • Photovoltaic panels on the roofs of Buildings A and B;
  • Variable refrigerant flow air source heat pumps to satisfy the heating and cooling requirements of all three buildings;
  • A combined heat and power unit to satisfy the hot water requirements of Building C;
  • One of the first hydrogen fuel cell CHP (Combined Heat and Power) systems in Wales, to generate heat and electricity for Building C.

These strategies resulted in all three buildings surpassing BREEAM Excellent requirements, a requirement for developments in Wales.

We used our Building Information Models (BIM) to generate data about the building’s maintainable assets, and held workshops with the Rhondda Cynon Taf County Council and their relevant stakeholders throughout the project about integrating this data with their adopted facilities management platform.

The nature of the project meant a Category B 'fit-out' delivery for two of the three buildings was added part-way through the build process, adding some complexity to delivering the project. Through collaborating with the sub-contractor, our teams were able to co-ordinate a design that minimised the need for any abortive re-work, smoothly facilitating the installation of equipment on site.

Solving challenges from the ground up

The site presented a raft of challenges for our civil, structural, and geo-environmental engineers, including its position, many former uses and neighbouring sites.

The first challenge was to deal with the 16,000 cubic metres of material left on site from demolition of the previous building. Our team aided the client in developing an enabling works package to completely reprocess and reuse this material during construction, rather than send it to landfill.

The proposed development had to incorporate and respect a number of existing features on site, including the existing retaining walls, bridge abutment and the flood defence wall. We developed a series of structural investigations in order to assess the construction, condition and function of the existing walls, developing an Agreement in Principle with Rhondda Cynon Taf Highways to allow an efficient approach to the repair works required. We also worked closely with the construction team and temporary works engineers to develop the sequence of works, from demolitions to new construction to ensure that the development could progress.

Buildings A and B included hand-laid brick facades, with a fully glazed ground floor, requiring a complex array of brickwork supports, horizontal and vertical movement joints and detailing.

The distinctive curved walls of Building C needed to be carefully engineered, utilizing a steel skeletal frame, over-clad with precision engineered timber panels utilizing laminated veneer lumber. The internal structure of the building also required careful design solutions, and as the gym and activity studio is situated above the library, managing vibration and acoustic control in long span (up to 15m) steel beams was a significant challenge.

All three buildings land on a podium slab, that undulates, slopes and steps to respect the existing tie-ins on Taff Street and Bridge Street in particular, maintaining a full footprint semi-basement with parking, plant and core facilities. The podium also includes a significant cantilever over the river, as well as sunken tree pits and is designed to accept fire engine access.

Bridging the gap

The site also features a Hydrock-engineered footbridge connecting it to Ynysangharad War Memorial Park and the National Lido of Wales. Our team delivered, from initial feasibility studies to detailed engineering design and construction, the £1.5m footbridge linking Llys Cadwyn to the historic Ynysangharad War Memorial Park.

The bridge is a dual-span cable-stayed steel bridge totalling 76m, starting on the Llys Cadwyn podium and crossing over the river with a central 25m high mast. Hydrock also undertook the lighting design for the bridge – respecting the ecological river corridor and geotechnical and flood risk analysis for the park-side abutment. The crossing provides an important pedestrian link from the new development and increases accessibility to the National Lido of Wales, Lido Ponty.

As part of our overall commitment to the scheme, Hydrock’s team on Llys Cadwyn joined forces with the whole project team in volunteering to refurbish one of the pavilions in nearby Ynysangharad Park.

Llys Cadwyn was awarded Development of the Year at the Insider Wales Property Awards 2020.

All images courtesy of Darnton B3/Phil Boorman Photography.