Unsupported browser

For a better experience please update your browser to its latest version.

Your browser appears to have cookies disabled. For the best experience of this website, please enable cookies in your browser

We use cookies to personalise your experience; learn more in our Privacy and Cookie Policy. You can opt out of some cookies by adjusting your browser settings; see the cookie policy for details. By using this site, you agree to our use of cookies.

The Sill by JDDK Architects

PHOTOS THE SILL index
  • Comment

A National Landscape Discovery Centre and youth hostel by JDDK Architects in the Hadrian’s Wall World Heritage Site within the Northumberland National Park. Photography by Sally Ann Norman and Kristen Mccluskie

The Sill is a National Landscape Discovery Centre and YHA hostel at Once Brewed and responds to the client Northumberland National Park Authority’s brief to create a high-quality facility to excite and inspire visitors to explore and engage with the landscape. The building features an exhibition space, learning and event spaces, a café, rural business hub, 86-bed youth hostel and a shop.

Situated in the Hadrian’s Wall World Heritage Site within the Northumberland National Park and partially covered by a Scheduled Ancient Monument, the design responds to this sensitive setting. Inspired by the geological outcrop The Great Whin Sill, the building grows from the landscape that surrounds it, appearing as another geological ripple. The Sill’s fully accessible living roof sweeps gently upwards, giving all visitors a bird’s eye vantage point across one of the UK’s most magnificent landscapes.

Dwgs the sill

Dwgs the sill

The Sill has been designed on sustainable principles. A central atrium brings daylight into the heart of the building while allowing natural ventilation. 

The south-facing entrance canopy provides solar shading while also supporting photovoltaics for generating electricity. Solar panels on the roof also provide hot water, while the remaining fully accessible roof space, covered with typical Whin Sill vegetation, increases biodiversity and reduces surface water run-off. 

Alison Thornton-Sykes, principal architect, JDDK Architects

PHOTOS THE SILL2

PHOTOS THE SILL2

Dwgs the sill2

Dwgs the sill2

Dwgs the sill3

Dwgs the sill3

Project data

Start on site September 2015
Completion June 2017
Gross internal floor area 3,070m²
Construction cost £8.8 million
Construction cost per m2 £2,866
Client Northumberland National Park Authority 
Architect JDDK Architects
Landscape architect Glen Kemp
Interpretation consultant Bricht 3D
Structural engineer Patrick Parsons
M&E consultant CAD 21
Quantity surveyor Gardiner & Theobald 
Project manager Gardiner & Theobald
CDM co-ordinator Gardiner & Theobald
Approved building inspector Northumberland County Council
Main contractor Sir Robert McAlpine
CAD software used Revit
Annual CO2 emissions 41 kg/m2

PHOTOS THE SILL3

PHOTOS THE SILL3

PHOTOS THE SILL4

PHOTOS THE SILL4

Detail and specification

The design of the 3,070m2 roof was the critical element on this project, as it had to support the indigenous flora with its specific substrate requirements, while allowing public access to the roof, keeping the building watertight and presenting minimal maintenance requirements to the client. 

Initial designs considered several different roof constructions, but the main exhibition area required 16m-plus spans, which meant the only option here was a 500mm-deep reinforced concrete deck, with the rest of the more cellular structures covered with a metal composite concrete deck.

Dwgs the sill4

Dwgs the sill4

After reviewing the available options for waterproofing the roof, initially a liquid applied solution was considered, however when looking at the maintenance required to fix any potential leak, this idea was discarded as moving 600 tonnes of topsoil and insulation would be too difficult. The solution was to use the only element common to all the different construction methods – concrete. Adding  Xypex to the mix was the ideal solution, as the entire structure should remain waterproof for the lifetime of the building and its self-repairing properties reduce maintenance of the structure and waterproofing to virtually zero.

By using this additive we also managed to overcome difficult roof-wall junctions to the basement, where the building goes underground and to eliminate additional drainage to the retaining walls.

Matthew Holmes, associate director, JDDK Architects

PHOTOS THE SILL5

PHOTOS THE SILL5

PHOTOS THE SILL6

PHOTOS THE SILL6

Selected products 

Waterproof concrete 
Xypex. XYPEX ADMIX C-1000 NF. Roof deck and retaining walls
www.xypex.com 

Roof drainage layer 
ABG. Roof Drain 40 and Deck Drain 2500 S. Beneath green roof
www.abg-geosynthetics.com

Roof insulation
Sundolitt. XPS and XPS upstand. Beneath green roof
www.sundolitt.co.uk

  • Comment

Have your say

You must sign in to make a comment

Please remember that the submission of any material is governed by our Terms and Conditions and by submitting material you confirm your agreement to these Terms and Conditions.

Links may be included in your comments but HTML is not permitted.

Related Jobs

Discover architecture career opportunities. Search and apply online for your dream job.
Find out more