Diary Entry No.13 – Final Finishes

The CREST Pavilion is now handed over to the client, South West College.  All the building works are complete and external grassing and landscaping is being left until the planting season.  This is a pleasing stage of the construction as we can see what the finished product looks like. In this diary entry we are going to discuss some of the finer details of the recent build. The image below shows the approach to the Pavilion with the large lecture hall on the right side, the large areas of glazing to the south assist with solar gain, a requirement of Passivhaus design.

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The following image shows the rear of the Pavilion with the external demonstration pads visible in the foreground.  These pads will be used for testing purposes for the new materials and technologies developed at the Pavilion.  The glazed corridor helps with solar gain, while the large overhang helps with solar shading during the warmest months of the year.  The high level glazing allows natural light to penetrate deep into the floor plan, reducing the amount of artificial light required to the exhibition spaces.

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We have previously discussed the extensive checklist of requirements for the Passivhaus Institute certification and BREEAM accreditation.  It is the combination of these criteria that enabled us to create one of the most sustainable projects in the UK and Ireland.  The pavilion has the following three sustainable credentials:

  1. Passivhaus Certified for Energy efficient envelope and ventilation system
  2. BREEAM excellent in terms of the BRE sustainable benchmark for UK commercials buildings
  3. The building will also be Net Zero Carbon, this means that the building can provide, by renewable energy, its own source of heat and lighting.

Whilst a combination of two of these sustainable criteria has been attempted in other parts of the UK, this will be the first example of the three criteria together and the pavilion will become a benchmark building for sustainability.

Achieving the requirements

The images above show the solar PV array that is both mounted on the building and ground mounted. The ground mounted panels are solar tracking, controlled by a robot to follow the sun to make them as efficient as possible.  The combination of these panels have enabled the building to be Net Zero Carbon, the panels produce enough electric to power all the Pavilions heating and lighting requirements

With careful planning and considered construction, we have been able to achieve the all the requirements for Passivhaus accreditation and are currently awaiting for certification. We achieved the airtightness requirement with days spent taping and adjusting window and door components to meet the Passivhaus required 0.6 air changes per hour.

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The image above shows the entrance to the Pavilion, the Glulam structural frame is visible throughout the whole building to tell the story about the construction techniques and sustainable materials used.

Since completion everyone agrees that the requirements for Passivhaus construction is much more onerous than those for traditional construction. We cannot find any disadvantages of Passivhaus except for perhaps the initial cost but this is more than regained as a result of the minimal space heating requirement and the comfort levels of the building to be in.

As the construction methods and Passivhaus approach are relatively new to Northern Ireland, a lot of time was put into pre build research. This research by Paul McAlister Architects is viewed as a valuable learning process for our practice. We hope to be able to implement the lessons that we have learned on this project and develop an easily buildable Passivhaus standard for further projects.

The success of the CREST Pavilion is all down to the collective team.  It was essential that those on site knew every aspect of the build and had an understanding, for example, of why it was so important to be careful to avoid puncturing the airtightness barrier.  To help achieve this, the architects and M&E consultants worked closely with the contractors on site to ensure that all parties were clear with how the build should progress and how services should be installed.

The connection between trades at every stage of the build was critical and the main contractor acknowledged that air tightness was one of the greatest challenges of the project. The relationship amongst the entire team has been vital; it all comes down to a good working partnership. Our clients at SWC have been very supportive, staying involved and following every stage of the design and build with great interest.  A series of videos captured by the client during the construction phase are available on the CREST website.

From the image above, it is apparent that the Passivhaus approach translates into high quality design and construction.  This is why we feel the Passivhaus certification is so important for quality assurance; it allows us to identify buildings which have truly strived to achieve the required criteria.

The structural frame of the building was designed to be timber from its initial concept as timber was a more sustainable material to use than traditional steelwork.  The Glulam structure of the pavilion is expressed in the internal spaces as part of the aesthetic of the scheme, and creates an elegant interior space.

An acoustic ceiling was required to satisfy the BREEAM noise credits that we were targeting.  To maintain the narrative of expressing the Glulam structure, the roof purlins have been left visible through the curve.

The Glulam structural frame continues externally in the link canopy that connects the new Pavilion to the existing college building and the refurbished office facilities that were completed in Phase one of the CREST works.  The image below shows the exposed Glulam timber supports to the link canopy.  The faceted cantilevered roof and the form of the building were driven by the Passivhaus and BREEAM requirements.

We, at Paul McAlister Architects, actively involve ourselves within the world of sustainable architecture.  We regularly attend lectures in order to maintain and develop our knowledge.  We strive to play a part in promoting Passivhaus design throughout the UK and Ireland.

For us, it has been an honour to be involved in such an innovative build project; we have enjoyed not only the practice of the design but watching the construction progress on site.  Having experienced the CREST Pavilion build from start to finish, we feel, more than ever, that the Passivhaus approach is the way forward in the UK and Ireland. Even if the environmentally responsible aspects were ignored, the advantages over ‘typical’ construction are obvious.  The Passivhaus design approach creates quality, comfortable buildings that serve to drastically reduce utility bills and significantly lessen the reliance on imported energy.