Historic slate museum restoration work to come before planners

Dale Spridgeon, local democracy reporter

Work to breathe new life into a historic Eryri tourist attraction is to come before planners.

Cyngor Gwynedd is to consider a full application for restoration works at the National Slate Museum in Llanberis. It will be considered by the planning committee on Monday, March 3, and has been recommended for approval by planning officers.

The proposals, submitted by Amgueddfa Cymru (Museum Cymru), describe internal and external alterations at the Grade I-listed Gilfach Ddu site.

The changes at the site include demolition of the café and shop, and the erection of new buildings – but “the vast majority of work is internal”.

A planning document said: “Formal planning consent is not required for these, but they have been assessed within the associated listed building application.”

Dinorwig slate quarry

The site was formerly the 19th century workshops of the once thriving Dinorwig slate quarry and has some of Britain’s best-preserved industrial buildings of the Victorian age.

As well as slate production, the site has features including a smithy, foundry and, on its eastern side, facilities to repair steam locomotives – the site situated at the north end of the narrow gauge Padarn Railway.

The quarry and workshops closed in 1969, with the museum opening in 1972.

In November, 2024, the museum announced a temporary closure amid news of a major £21m upgrade and is not anticipated to re-open until 2026.

The museum had previously stated that restoration of the site would transform it into a “world-class visitor attraction” at the heart of the Slate Landscape of Northwest Wales, a UNESCO World Heritage site.

‘Character’

Planning documents state it is hoped the work will “add to the character as well as the enjoyment of the site as a whole by improving visitors’ experience”.

The proposal states: “There has not been any investment in the site for some time and by now the buildings are deteriorating and lacking modern facilities for visitors.”

New buildings have been “designed carefully” in relation to the existing site.

Among changes is the demolishing a circular shaped shop and reconstructing it with a new square building.

“Overall, the site forms part of the previous quarry, and the designs of the dormer windows to the new café for example have been taken from the historical slopes to follow the same pattern,” plans note.

A new exhibition room is also planned in the southern section of the site.

The plans described the Gilfach Ddu site as “striking and important” within the village, noting its culture and history “within living memory”.

“Therefore, any alteration to the site must be dealt with very sensitively, and it is felt that the treatment of the work to the main buildings is the minimum required to restore and to secure them for the future,” plans say.

“It’s felt that the treatment of the new buildings including the new café follow the pattern in terms of the design, materials and existing colours around the site and will not create any alien element.”

The proposal say: “The café is a modern building, and it is proposed to demolish this and re-build a new building on the same footprint but significantly larger.

“It is intended to have a café, kitchen, toilets and an education room on the ground floor together with a bin and recycling area, with the first floor providing another education room and toilets.”