Pochin Construction has completed Welsh Assembly Government's new regional office in Junction, North Wales.
First Minister of Wales Carwyn Jones picked up the keys for the new office as he marked the end of the construction of the building.
Pochin completed the £20.2m contract on time at the end of April and there will now be a fit-out period before staff start to move in over the summer.
Welsh Assembly Government, the agency, led by Gwynedd Council, maintains and manages 300 miles of trunk roads in North Wales and undertakes capital improvements.
First Minister Jones said: "This is a building both the Welsh Assembly Government and North Wales can be proud of. Its design reflects the heritage of the area, whilst making as little impact on the environment as possible. It is a striking landmark building which will be open to the public, and I hope as many people as possible come to see it when it opens.
"This building has been completed on time and on budget and I'd like to thank all those involved including the construction team, the main contractor Pochin and all other contractors.
"It is no small achievement to complete a building on this scale and to achieve such high environmental standards – BREEAM 'Excellent' rating and an A-rated Energy Performance Certificate.
"This office is an investment in the long term and will bring sustained benefits to North Wales as a result. The creation of a large office improves the career prospects of existing staff in North Wales and helps brings jobs to the area."
Jon Pochin, managing director of Pochin Construction, added: "This magnificent building makes me feel extremely proud of the Pochin Construction team, all our sub-contractors and the Welsh Assembly Government's project management team who have worked collaboratively to ensure that this handover was on-time.
"We have enjoyed working with the Welsh Assembly Government and I thank all involved."
David Stafford, director of S I Sealy & Associates, the mechanical and electrical engineering design consultancy for the building, said: "This building is an exemplar of the use of low and renewable energy technologies, such as a biomass boiler plant, ammonia chiller plant, rainwater harvesting and natural ventilation. It is great to work with a client, such as the Welsh Assembly Government, which has such a strong desire to occupy a low carbon footprint building."
The First Minister also buried the time capsule in the reception area of the new office. The contents of the time capsule has been chosen by pupils from four local schools; Ysgol y Creuddyn, Ysgol Aberconwy, Ysgol Maelgwn and Ysgol Nant y Coed. They have been working for over a year on the project.
First Minister Jones added: "One of the main advantages of this new office will be better links between the Welsh Assembly Government and the communities we serve. This project with the time capsule is an example of that and I hope that the links we have built with the pupils and the schools will continue into the future. The new office will have a public area called Y Bont and schools in North Wales will be invited to take advantage of this new and innovative facility.
"This time capsule will now remain underground for fifty years and we can only imagine what changes will have taken place in Wales by then. I'd like to congratulate the pupils for the ideas they had for the content which will give a snapshot of life in Wales in 2010 to those who will be in this office in 2060."
The content of the time capsule includes: school dinner menus, DVDs of school performances, a local newspaper, school uniforms, a map of Wales and a toothbrush.
David Williams, project director at Austin-Smith:Lord, the architects appointed to develop the design of the building, said: "One of the challenges we faced was to reconcile the modern form with the use of traditional materials in order to respect the heritage of the area whilst achieving the high quality design expectations. The building was completed over 16 months from detail design to completion, dovetailing with the Contractors Procurement Strategy.
"The key to delivering such a high profile project was tight communication and our pro-active relationship with both Pochins and the Welsh Assembly Government's team."
There will be an official opening in the autumn of this year.