Australian Building Codes Board Conference, September 2011

The presentation slides from the conference are now available for view or download on the ABCB website.

The Australian Building Codes Board held it's biennial Building Australia's Future Conference (BAF) on the Gold Coast, Queensland in September 2011. 

Many thanks to the ABCB for giving me the opportunity to present on the subject of condensation.  Pushing the envelope - Have we considered condensation?

Fortunately the hecklers kept quiet and the presentation on the content of the ABCB Condensation Handbook certainly generated a bit of interest for the remainder of the conference.

I would highly recommend taking a look at some of the other presentations, particularly in the morning sessions on day 3.

Phil Wilkinson, the Chief Executive Officer of AIRAH gave a very entertaining and graphic presentation on the consequences of poor maintenance of HVAC systems including the "Hall of Shame."    Advice from a plant lover - Making sure HVAC systems stay green 

Dennis D’Arcy, CEO of the Insulation Council of Australia and New Zealand discussed the diminishing marginal benefit of ceiling and wall insulation in both heating and cooling climates.  Making the DTS work for you

Tony Tannar of the Roofing Tile Association of Australia presented some very interesting findings from the ongoing research at the University of Newcastle.  Solar absorptance and energy efficiency - What role does solar absorptance of roof cover play in determining heating and cooling loads?

This is an area of particular personal interest and the results seem to reinforce findings from William Miller's work at ORNL and the D-Air research group in Japan including at Kamisei Roof Tiles.

It is not just a matter of the values for solar absorptance/reflectance of metal roofs and roof tiles but also about roof space ventilation both above and below the substrate or sarking.

The findings of the research will challenge some "accepted" thinking in the industry and I hope will have long term implications for future roof design and product development and feed into getting a greater correlation between standards, requirement and actual performance.

All the presentation slides can be found from links on the ABCB web site.

http://www.abcb.gov.au/education-events-resources/national-conference/day-3

When visiting the CBD of Sydney of late I have been trying to take a detour past the recently complete office tower, 1 Bligh Street.

Designed by Architectus, in association with Ingenhoven Architects in Germany, the sustainable office tower achieved the 6 Star Green Star Office Design V2 Certified Rating from the Green Building Council of Australia and has won a series of awards recently including the 2011 UDIA NSW Awards for Excellence – Retail/Commercial Development.

Besides my interest in the double skin façade and other sustainable features, this is also one of the first projects in Australia to use the ProctorWrap Black Label - a recent addition to our range of vapour permeable sarking membranes. The membrane was used behind the green wall designed and installed by Fytogreen.

Plenty of positives from greens on the side, Sydney Morning Herald, David Adams, 19 Nov2011.

Erwin Taal, a landscape architect and spokesman for the Australian Institute of Landscape Architects, says wall gardens are growing in popularity.

He ascribes the demand to new products, the need to make the most of space and the environmental benefits, which can include improving air quality and filtering water runoff.

“People like the idea of a salad bar or a herb wall or something like that, rather than traditional pots or hanging gardens,'' he says.

Vertical gardens can be as little as one or two square metres, or cover an entire wall or walls.

http://smh.domain.com.au/design-and-living/plenty-of-positives-from-greens-on-the-side-20111118-1nlp1.html

In addition to the green façade, some of the other features that led to 1 Bligh St receiving the six star accreditation are:

• Full building height naturally ventilated glass atrium providing a flow of fresh air and a sense of openness on every floor.
• First high-rise office tower in Australia to feature a double-skin, glass façade. The outer skin protects computer-controlled sun shades, shielding the double glazed curtain wall from the sun, whilst reflecting natural light into the building.
• Hybrid variable air volume (VAV) with a chilled beam air conditioning system.
• Tri-generation system that uses gas and solar energy to generate cooling, heating and electricity. The series of curved solar thermal collectors provide the energy to drive the cooling systems.
• Black water recycling is used amongst other things, to irrigate the feature green wall, rooftop terrace and plantings throughout the building.

The iconic Albany Entertainment Centre wins excellence in construction award

Congratulations to Doric and H. M. Metalcraft for being awarded the prestigious 2011 Master Builders-Bankwest Excellence in Construction Award.

Doric took home four highly coveted awards in this years presentation, including;

• 2011 Best Regional Project
  Doric, Albany Entertainment Centre
   
• Best Public Use Building
  Doric, Albany Entertainment Centre 
   
• Best Steel Construction
  Doric, Albany Entertainment Centre 

• Best State Government Building, Regional WA
  Doric, Albany Entertainment Centre 
   
• Subcontractor Award for Cladding
  H.M. Metalcraft, Albany Entertainment Centre

The Albany Entertainment Centre development is one that Proctor Group Australia are very proud to be have been a part of. Proctor's Roofshield breathable membrane has been installed behind the impressive zinc cladding to prevent moisture ingress whilst still allowing water vapour to escape. The Proctor Roofshield membrane reduced the risk of mould growth and corrosion within the building structure, effectively allowing the building to breathe.

For more information please click here.

Rain screens, while common in Europe and North America, have begun to emerge to a greater degree in discussions within the Australian architecture and design community. A rain screen system offers numerous benefits in moisture-management and energy-efficiency but when I dig deep into conversations over the past couple years with local architects, façade consultants, suppliers and installers there is a huge variety of perceptions on what “rain screen” actually means and what the key design components are.

I recently came across an excellent document jointly published by the Ontario Institute of Architects and available for free for download from the Canadian Mortgage and Housing Corporation.

Page 26 includes an excellent checklist of 10 critical points in rain screen details.

1. Provision for water shedding at the outer cladding, away from joints, with drips under any projections to prevent water collecting at the building face.
2. A cavity of appropriate width to allow pressure equalization across the cladding system and prevent capillary movement (allow for construction tolerances!).
3. A continuous and effective (for example, airtight to a maximum air leakage of 0.1 L/s/m2) air barrier within the backup wall.
4. Drainage of the cavity through continuous flashings and weep openings, and proper management of drained water.
5. Adequate venting of the cavity provided through properly located openings in the cladding (appropriate ratio achieved between vent area and leakage of air barrier and seals).
6. Additional provision for drainage at the backup wall (located on the “warm” side of the insulation to avoid condensation problems).
7. Effective compartmentalization of the cavity at each building face with airtight seals, and additionally across the width of the façade as required (refer to calculations).
8. Sufficient rigidity and/or structural support of the air barrier to resist wind loads and limit deflection.
9. Sufficient rigidity of the cladding to limit deflection and resist wind loads as required.
10. Special attention paid to water-resistance and drainage at building edges and parapets (areas subject to heaviest rain-wetting and wind pressure differences, where pressure equalization may not be achievable)

The National Association of Home Builders (NAHB) in the US outline the advantages of rain screen

• It neutralizes physical forces inducing water intrusion.
• It is a simple, forgiving system with built-in, multi-layered redundancy, and
• It has integrated drainage and ventilation that accelerates cavity moisture removal.

Rain screens prevent or reduce moisture problems in exterior walls, including siding rot and peeling paint. Thermal shock, solar driven moisture effects, and pressure forces are diminished. In high moisture environments, the additional cost and complexity of Pressure Equalized Rain Screen construction may be cost effective over the long term.

Rain screen designs do not increase the cost of drainable EIFS and brick veneer wall systems. To install the air space behind the cladding in most assemblies, however, costs for furring or other spacer materials cause costs to increase. The few cents per square foot spent on a rain screen offer exceptional value to design professionals seeking liability protection, builders wanting to avoid call backs, and homeowners looking for comfort.

The Proctor range of vapour permeable membranes ProctorWrap High Tensile, Air Tight and Black Label can play an important part in meeting these requirements and provide a continuous air barrier. In particular the Black Label has been designed with high UV resistance for use in open joint rain screen applications.

One area of debate is if a flexible membrane can be relied upon as the air barrier in pressure equalized rain screen design without a rigid substrate. Point 8 above advises that a “sufficient rigidity and/or structural support of the air barrier to resist wind loads and limit deflection,” is required.

Studies by the Institute for Research and Construction in Canada report that the performance of the air barrier system affects the ability of the wall assembly to achieve pressure equalization across the rain screen, by reducing the flow of air through the wall assembly, and greatly contributing toward reducing the air pressure differential across the rain screen.

“Under dynamic-pressure conditions, recent IRC studies indicate that excessive flexibility of the air barrier system will result in fluctuations in the volume of the air chamber compartment. These fluctuations adversely affect the potential for rapid pressure equalization across the rainscreen.”

Chown, G.A., Poirier, G.F. and W.C. Brown, “Designing Exterior Walls According to the Rainscreen Principle”; Technology Update No. 17, Institute for Research in Construction, National Research Council of Canada, 1998. http://www.nrc-cnrc.gc.ca/obj/irc/doc/ctu-n34_eng.pdf

It is clear that in order to attain the full benefits of rain screen then we need at the outset a clearer understanding of the function of the rains screen and what is required for the building envelop to function as such.

Download the full CMHC document here: http://www.cmhc-schl.gc.ca/en/inpr/bude/himu/coedar/upload/The-Rain-Screen-Wall-System.pdf

Is it any wonder that heated indoor swimming pool roofs in Australia tend to have a very short life span and are a constant source of moisture and corrosion related headaches for facilities managers and local authorities that need to ensure their facilities remain open and provide a safe environment.

Next time you are at the local swimming pool take a look up the roof and keep an eye out for damp staining on suspended ceilings. If the foil faced insulation blanket is exposed, is it in good condition and continuous? At my local pool I was not surprised at what I saw. (see images) 

The pool just down the road at Lane Cove has suffered corrosion, with the local council already down $1million in legal fees over the past 4 years as part of an action taken against the builders and architects.

In Victoria, closure for refurbishment of the Collingwood aquatic centre was brought forward as the council was forced to close twice in six months because of problems with a 30 year old “ageing roof structure.”

In Canberra, the original Australian Institute of Sport Aquatic Centre is on its third roof since 1984 after requiring major structural work in 2010 to resolve corrosion issues resulting from condensation. This work had to be completed with the added complication of keeping the facility open.

Anyone involved in the design of indoor swimming pools or investigating condensation related issues with a swimming pool should read Joseph W. Lstiburek’s very accessible Building Science Insight which is an edited version of the insight that first appeared in the ASHRAE Journal.

“The problem is fundamentally pretty straightforward. We have a huge internal moisture load that, for once, you cannot blame on your mechanical engineer or HVAC contractor. There’s a pool filled with water in your building for Pete’s sake. You can’t dehumidify your way out of the problem; you can’t ventilate your way out of the problem. You can localize the problem by  depressurizing the pool area relative to adjacent spaces or by pressurizing a boundary space between the pool area and adjacent areas, but, in the pool area, you are pretty much toast.” 

“We need to be perfect. And the only wall that will work, of course, is “the perfect wall.” We have been here before. Put the water control layer, the air control layer, the vapor control layer and the thermal control layer on the outside of the structure.  Put everything else inside, especially the services. Same for the roof. Done.”

“A few little tricks of the trade – think of cladding as a dehumidifier that sucks moisture out of the shaded stuff. That means the back of the cladding will get wet if there is a flaw in your wall. What are the odds of there being a flaw or less than perfect workmanship?  If  I  were  using wood cladding, I would not just back ventilate it, I would back-coat it with primer and paint. Just like the old guys used to. I do not want the wood to absorb water.  If it does, it can leach tannins and other water-soluble extractives. Ask me how I know?” 

“If it is cement siding, you had better coat it on the backside, as well as ventilate it. If you have brick, you had better ventilate the heck out of the space.”

“If it is metal, you had better think a lot about stainless steel and magic pookey to protect it, as well as good cladding ventilation. If there is a flaw and air gets out, the air is going to be carrying more than just water vapor: chlorine, bromine and other aggressive oxidizing (a.k.a. corrosive) agents. You ever see what they put into the water? It will eat your insides out and the insides of your wall assembly as well.”

Not in reference to Top Gun, but the1983 film “Risky Business,” building science guru Joseph Lstiburek in his own inimitable style has this month published his latest Building Science Insight entitled “Risky Business : High Risk Walls.”

For anyone designing buildings that incorporate tilt-up concrete walls, particularly in the colder and temperate climate zones of Australia, and plan to insulate on the inside of the panel, this very readable paper is well worth taking a look at.

Unfortunately we have seen first hand this winter, such walls going badly wrong and suspect there will be more out there. Below is an extract from the edited version of this insight which first appeared in the ASHRAE Journal.

"As my friend Mac Pierce likes to point out: you could get a blindfolded drunk epileptic to cross Niagara Falls on a high wire without a net, but it wouldn’t be a good idea. There are some wall assemblies that are like that. One in particular irritates me. It has lead to a great deal of grief. It has problems that can easily be avoided. But simple analysis shows it works, and that is the rub. The simple analysis shows that it works, but the real world shows that it does not.

It gets better. More complicated analysis shows that it sometimes works, and truth be told, the real world shows that it also sometimes works. No moisture and exceptional workmanship can make it work. What are the odds? Clint Eastwood thermodynamics again: do you feel lucky punk? Well, do you?

So what does this wall look like? I am not sure what to call it. It has a face-sealed cladding (“perfect barrier”) that is impermeable to water vapor. It is insulated on the interior with air permeable insulation usually held in place between steel studs or impaled on pins protruding from the back of the cladding and covered by a vapor barrier. Let’s call it a “Tom Cruise Wall.”

The insulation is typically a fiberglass batt “smushed” between steel studs. Sometimes, it is rockwool or mineral wool pinned to the interior of the exterior cladding. The fiberglass batt sometimes comes with a foil facing – the “vapor barrier.” More often the whole kit and kaboodle is covered with sheet polyethylene that may, or may not, be called an “air-vapor barrier.” Yuck.

So what is the problem? Well, the cladding is easy to make almost perfectly airtight and the interior lining is almost impossible to make airtight. That’s it? Really? That simple? Yup. You’re kidding. Everyone knows you can’t seal plastic sheets on the inside of wall assemblies and make them airtight."

 The full paper is available from www.buildingscience.com or directly by downloading here

The ABCB Condensation Handook Released

In partnership with the Australian Institute of Architects and industry, the ABCB has produced a Non-Mandatory Handbook to provide greater clarification for managing condensation in buildings.

It was a privilege to work over the past year with the entire group that undertook on the challenge of writing this handbook. The ABCB and Australian Institute of Architects really do have to be commended for taking the initiative to put this together. I hope that this will reduce the number of condensation related problems in new build and existing buildings being upgraded to improve the energy efficiency of Austalia's commercial and residential building stock. 

Here is what the ABCB say about the handbook. 

This Non-Mandatory Handbook is intended to assist architects, designers and builders in the assessment and the management of the risk of condensation and its consequences in the contemporary industry environment and should be read in conjunction with the BCA provisions relating to Damp and Weather Proofing, and Energy Efficiency in all classes of buildings.

Appropriate detailing of buildings ensures they remain serviceable, the occupants remain healthy and that the design life of the building is not compromised.  The outcome of failing to adequately detail for moisture control is a common underlying cause of many reported building failures.  The rectification of the side-effects of condensation can result in costly repairs and in the case of related fungal and mould infestations, prohibitively expensive repairs. 

 Traditionally our buildings were not airtight and had little or no insulation.  However, as a result of changing occupant practices and the introduction of mandatory energy efficiency requirements, building practices are changing, requiring a change in detailing so that moisture related problems are adequately managed. 

 While a common cause of moisture related problems is due to water ingress, the focus of this Handbook is controlling moisture within the building’s fabric resulting from condensation.

Handbook is available for free download here.

In June when I was back in the UK I met with a former colleugue Mike Mapston of Building Envelope Evolution. They have been working with the Swedish company A-Hus Professional in the UK, one of the 3 main partners behind One Tonne Life Project. 

Mike pointed me towards the one tonne life blog here.

On the blog you can follow the efforts of the Lindell family in Swewden in their attempt to reach a target of a one tonne of carbon dioxide per person per year lifestyle.

The final report has just been released and is available for download in English on the One Tonne Life website here. 

What is the One Tonne Life Project

"One Tonne Life” is a project in which A-hus, Vattenfall and the Volvo Car Corporation joined forces with industry partners ICA and Siemens to create a climate-smart household.

Over a period of six months, the Lindell test family lived a climate-smart lifestyle with the aim of reducing their carbon dioxide emissions from 7.3 tonnes per year, which is roughly the average in Sweden, to a minimalistic one tonne. After an impressive final sprint, the Lindells crossed the finishing line at 1.5 tonnes.

The Lindells exchanged their 1970s home and their almost 10-year-old cars for a newly built, climate-smart wooden house from A-hus and a battery-powered Volvo C30 electric. Vattenfall provided renewable electricity, new energy technology and energy coaching. ICA and Siemens were industry partners for food and household appliances respectively. Method development and calculation of the family’s carbon dioxide footprint took place in partnership with the Chalmers University of Technology and the City of Stockholm’s environment and Health Administration.

Viewed per category, the Lindells managed to reduce their CO2 emissions from transport by almost 95 percent, from food by 80 percent, from accommodation by 60 percent and in other areas by 50 percent. All told this means their CO2 footprint shrank by 75 percent." www.onetonnelife.com.au

As part of Australian Institute of Architects (AIA) 2011 Refuel National Seminar Series I will be presenting around the country during August and September.

Full details are available on the AIA website here  

Leaks & Seals: Avoiding condensation through smart design

We all know how important it is to keep rain out of buildings but if it is sealed up too tight how do we stop it getting wet from the inside? 

The drive for energy efficient buildings with improved air tightness and insulation, and efforts to seal up the building, changes the dynamics of the building envelope but a building still needs to breathe.

Through a combination of case studies and sound technical information, this seminar, considers how the building envelope needs to deal with water in its various forms and how considered design and detailing can minimise and prevent damage.

Confirmed dates are listed below.

To register for Leaks & Seals: Avoiding condensation through smart design in your local state or territory
please go to the AIA website  click here.