Passivhaus Affiliate

Greendale Studio receives Passivhaus certification

Greendale Studio in Canterbury has recently been certified by Warm. The building is a commercial art studio for Cooke Industries and claims to be the first of its kind to be certified in the UK. Trust member’s Conker Conservation Ltd were the Passivhaus designers on this project and were involved in the detailed design as well. 

The building posed a considerable challenge in meeting the Passivhaus criteria, due to its surface area to floor area ratio (required by planning restrictions and building usage) and by the industrial fume extract and lighting design necessary for a commercial art studio.

Artworks of up to 3m high x 6m wide are created on the premises, using air craft grade aluminium frames and advanced canvases therefore high ceilings and plenty of day light were needed, along with an advanced  lighting system.

Many options were explored with assistance from the UK Certifier, Warm, and the Passivhaus Institut in Darmstad, Germany.  The result was a radical change in the types of paints used; high VOC paints were ditched along with their environmental and health impacts.  This allowed a much lower capacity ventilation system to be used, saving money in installation and running costs.

In the quest to create an airtight, highly insulated building envelope without thermal bridges (weaknesses in the insulation layer) a timber portal frame was devised using ‘I’ joists.  Following the original suggestion by Paul Mallion, was proven mathematically by engineer Stephen Green, and tested in prototype by EcoFrame Systems Ltd.  The method employs bonding ‘I’ joists together using laser cut plates of plywood into the webs of the joists using high strength polyurethane glue.  This method avoids the need for tie beams at ceiling level, which create both a thermal bridge and potential air gaps for draughts.

So far this winter the heating has not been needed, proving how effective the passivhaus approach is.

Other features include:

  • 3m high loading door, insulated to passivhaus level, with a U value of 0.673 W/m²K.
  • Triple glazed frameless picture windows to the south west elevation.
  • Rammed chalk mass wall to stabilise internal temperatures.
  • Wood pellet fired district heating system serving the 3 properties on the site.
  • Externally the building is clad in finger jointed sweet chestnut from Kent and East Sussex.
  • The roof has 5.6m² of solar thermal panels.
  • 22.5m² of photovoltaics generating 2.5kW of electricity.

16th February 2012


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