The John Hope Gateway, Royal Botanic Garden Edinburgh

The John Hope Gateway, Royal Botanic Garden Edinburgh

Provided by Edward Cullinan Architects

 

 

Entrance lobby

Interior of the entrance foyer: looking towards the rainwater collection tank serving the WC’s below. © Matt Laver photography.

Architect: Edward Cullinan Architects Ltd

Address of project: Arboretum Place, Edinburgh, EH3 5LR

Construction Cost: £10.7m

Year of Completion: 2009

Client: Royal Botanic Garden Edinburgh

Quantity Surveyor: David Langdon

Structural Engineer: Buro Happold

Services Engineer: Max Fordham LLP

Landscape Architect: Gross Max

Lighting Designer: Speirs & Major

Exhibition Designer: Bright 3D

Project Manager: E C Harris

Main Contractor: Xircon

 

 

 

 

 

 

 

The design problem

Street elevation at night

At night: Street-side elevation of the John Hope Gateway. © Matt Laver photography. 

The new John Hope Gateway Building needed to integrate into the special and sensitive landscape of the Royal Botanic Garden Edinburgh and provide a front door to one of the world’s leading botanical institutions.
The Garden has long been enjoyed by the public but was often seen as a special park, rather than an educational and scientific resource. It suffered from multiple access points with no visitor welcome or orientation. The Gateway was designed to resolve these issues and underpin their mission, “to explore and explain the world of plants”.
The new building was to be a showcase for sustainable design and include many low energy technologies. Wherever possible, the building was to be made out of natural materials with low embodied energy, including a structure and finishes predominantly in timber to demonstrate the importance of trees.

 

The site

The context for the design of the new John Hope Gateway was the contours, paths and trees of a mature landscape and a grand circular forecourt.
Located at the West Gate of the Garden, the site is at an important confluence of routes at the base of a hill; the long axis from Inverleith Park leading up to the Inverleith House gallery and the perimeter circular path around the Garden.
It was constructed over the site of a collection of separate buildings including the former shop and WC’s, which no longer met the Gardens needs. This minimised the loss of land for the Garden. It also provided a street frontage to Arboretum Place, which allowed straight-forward deliveries to the café, shop and exhibition and out-of-hours access for events in the Gateway.

Routes diagram

Primary routes around the garden. © Edward Cullinan Architects Ltd.

 

Site plan

Site plan drawing. © Edward Cullinan Architects Ltd.

 

 

 

The architectural response

Our architectural response to a special place:

  • The entrance frames a view of the Garden between slate walls and a projecting timber roof plane.
  • Internally, routes and views across the building radiate from a double height central hall to the landscape beyond.
  • Carved into the contours, a long curving window looks into a new biodiversity garden containing a rich living plant collection.
  • On the upper floor, an education room and restaurant open onto a large roof terrace which overlooks and bridges back into the Garden.
  • Supported on a diagonal timber roof structure on slender steel columns, the roof floats as a single horizontal plane to form a deep overhanging canopy.
  • Sustainable features integrated such as a biomass boiler, rain water harvesting, a wind turbine, solar collectors and photovoltaic solar panels.
  • The building expresses the inherent qualities of stone, timber, concrete and glass and celebrates how they are assembled.

 

Diagram 1

Axis from Inverleith Park up to Inverleith House. © Edward Cullinan Architects Ltd.

Diagram 2

Stone walls reinforce axis. © Edward Cullinan Architects Ltd.

Diagram 3

The ground floor plane. © Edward Cullinan Architects Ltd.

 

Diagram 4

The garden cuts into the building. © Edward Cullinan Architects Ltd.

Diagram 5

A new biodiversity garden created. © Edward Cullinan Architects Ltd.

Diagram 6

Public and private accommodation locks around a first floor void. © Edward Cullinan Architects Ltd.

 

Diagram 7

A green roof floats over and unifies. © Edward Cullinan Architects Ltd.

Routes diagram 2

Routes into the building. © Edward Cullinan Architects Ltd.

 

 

The building

Ground floor plan

Ground floor plan. © Edward Cullinan Architects Ltd.

First floor plan

 First floor plan. © Edward Cullinan Architects Ltd.

Section looking North West

Section looking North West. © Edward Cullinan Architects Ltd.

 

Section looking North East

Section looking North East. © Edward Cullinan Architects Ltd.

Elevation looking South East

Elevation looking South East. © Edward Cullinan Architects Ltd.

Ground floor

The helical stair and reception desk are made of Structural Veneer Lumber (SVL) and rooflights from ETFE.
© Matt Laver photography.

 

Street elevation

Street-side elevation of the John Hope Gateway. © Matt Laver photography.

Secondary structure

Structural assembly.
© Edward Cullinan Architects Ltd.

 

 

Design strategies

  • Timber:
    • White pine, glulam timber from France for the primary and secondary beams.
    • Cross laminated spruce timber panels sourced from Austria.
    • Douglas Fir Structural Veneered Lumber (SVL) from Germany for the helical stair, major items of furniture, and mullions & transoms for the timber glazing system.
  • Rainwater Catchment: 
    • Rainwater Harvesting for WC flushing and irrigation is collected from main roof in agricultural-style storage vessels, (2No. 7000 litre tanks (5000 litre per tank dedicated to rainwater storage). This reduces amount of potable water needlessly flushed down WC’s by at least a third per year, (WC water use predicted at 928 m3/yr. Annual rainwater use estimate 333m3/Yr).
    • Gravity treatment cyclonic filters for course filtration only (no additional treatment for brown water discoloration from sedum roof etc).
    • Rainwater harvesting to the north toilet drum is gravity fed. Rainwater harvesting to the south end of the building is pumped with the booster set to allow all WC’s in building to be served.
  • Solar water heating:
    • 15 m2 of evacuated tube solar thermal panels mounted on the roof.
    • Provides enough hot water for 100,000 hand washes or 1500 showers per year.
  • Photovoltaics:
    • 11m2 of PV’s mounted on the roof.
    • Produces a peak output of 1.5 kW of electricity.
    • The photovoltaic panels will reduce the amount of energy required form the national grid by 1400 kWh/year which equates to a carbon saving of 600 Kg of CO2 per year.
  • Biomass:
    • Primary source for heating and hot water
    • Boiler Capacity = 200 kW
    • Biomass Silo = 66 m3
    • Estimated Fuel deliveries per year = 9
  • On site wind power:
    • Most overt sustainable design feature - a potent symbol of the environmental ethos of The Gateway.
    • 6kW QR5 vertical axis turbine
    • Reduce amount of energy from grid by 8500 kWh/year

 

Lessons learned

Successes:

Use of structural timber: Cross laminated timber and SVL. Gained understanding of limits and possibilities of the products.

  • Use of Corten steel – not used this material before and pleased with properties and colour and texture, particularly how it contrasted with garden setting.
  • Use of Caithness slate in split riven faced coursing– great craftsmanship and beautiful material.
  • ETFE rooflights – clear span across 8 x 24m openings – very effective.
  • SVL window system – extremely elegant
  • Polished plaster – great colour effect
  • Sedum roof – strong visual effect, limits solar gain, attenuates water run-off, insulates

 

Challenges:

  • Wind turbine – encountered several technical problems before working.
  • Biomass boiler – encountered several technical problems before working.
  • Timber floor finish – client not happy with manufacturer’s recommended soap finish – too labour intensive to clean – eventually lacquer applied.
  • Locating acceptable fire treatment to exposed cross laminated timber soffits and walls inorder to avoid a treatment that yellowed the timber which required detailed research to be undertaken.

 

Take this further

  • Building Design, 7 September 2007
  • Building Design, 7 December 2007
  • Architectural Review, May 2008
  • AJ Specification January 2009
  • RIBA Journal August 2009
  • AJ No. 4 Vol. 232 22/7/10
  • Building Issue 29 23/7/10
  • BREEAM & EPC RATING:
    No BREEAM assessment was carried out on the building.
    Designed to achieve an EPC rating of “A”, 7 Kg/CO/m/year, 22
    (not including display lighting (in the exhibition area or restaurant) or small
    power (computers etc)).
    Recent modelling showed the design should achieve B+,16kg/CO2/m2/yr. Note: The EPC rating is currently being validated by the assessor and has not been officially issued. In line with the building regulations the EPC does not include catering gas or display lighting.

 

Related case studies

TimberRainwater catchment, Solar water heating, Photovoltaics, Biomass

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