When the Senedd building first opened its doors on St David’s Day 2006, it became the new home for Welsh democracy – the first dedicated parliament building built in Wales for over 600 years.
Two decades on, the building remains a symbol of open, modern, and sustainable democracy. This anniversary year happens to coincide with an election on 7 May, giving the people of Wales the chance to help shape the future of their communities.
Democracy in design
The Senedd was designed by the Richard Rogers Partnership (now Rogers Stirk Harbour and Partners) after an international architectural competition.
Transparency you can see
Much of the exterior is made from glass, allowing people to look directly into the heart of democracy. Public spaces flow into the building, reflecting that the Senedd serves and welcomes the people of Wales.
Power from the people
Inside, the public gallery sits above the Siambr (debating chamber), symbolising that democratic power comes from the people of Wales.
Put simply: the public quite literally has the highest seat in the Senedd.
Sustainability in mind – before it was the norm
The Senedd set a new standard for sustainable public buildings when it opened it 2006. Many features now considered ‘modern green design’ were already built into it 20 years ago.
- Natural light, by design: Large glazed walls, white surfaces and the mirror-like cone (conical) at the top of the funnel reflect daylight into public spaces and the Siambr – reducing the need for artificial lighting. Sensors ensure lights only come on when needed.
- Natural ventilation: A six-metre rotating roof cowl draws warm air up through the central funnel, while automated windows bring in fresh air – greatly reducing reliance on energy intensive air conditioning. ‑metre rotating roof cowl draws warm air up through the‑intensive air conditioning.
- Ground‑source heating and cooling: 27 boreholes, each around 100 metres deep, help warm the building in winter and cool it in summer through an underfloor system.
- Biomass heating: A biomass boiler using sustainably sourced wood chips provides a low‑carbon heat source.
- New heat network: Heating will soon move to the Cardiff Heat Network, which uses surplus heat from a nearby energy facility –the latest innovation in low‑carbon technology.
- Rainwater harvesting: Rainwater from the roof is collected and reused for flushing and cleaning – equivalent to around 100,000 glasses of water – reducing demand on mains supply.
These decisions, together with long-lasting materials, such as Welsh slate and concrete, were made to cut environmental impact, reduce waste and minimise maintenance over the building’s lifetime.
A new Siambr for a new Senedd
From May 2026, the Senedd will have 96 Members instead of 60.
This will give the Senedd greater ability to challenge the Welsh Government on important issues like health services, education and transport. This means your community will have a stronger voice in decisions that affect them.
To prepare for these changes, the Siambr has been redesigned with:
- improved accessibility
- enhanced digital and broadcasting equipment
- better public viewing experience
The upgrades were made with an ongoing commitment to sustainability re-using as much of the original Siambr as possible, and maximising opportunities to use Welsh materials and a Welsh supply chain.
These upgrades ensure that people can continue to follow democratic debates clearly and easily, whether they visit in person or watch online.
Visit the Senedd
The Senedd is free to visit and welcomes everyone.
Whether you’re interested in Welsh politics, architecture, sustainability or simply want to explore an iconic building overlooking Cardiff Bay, there’s plenty to enjoy – from guided tours and exhibitions to family-friendly activities.
Plan your visit today and celebrate 20 years of the home of democracy in Wales.
