osman designpac
building designers
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It’s Part of theSustainable Design Equation for Comfortable Healthy Living and Work.
The essence of good solar passive design is to effectively control the amount of direct sunlight that enters the building at various times of the year without any moving parts. Passive solar design provides shade in summer, and equally to providesun penetration in the winter months.
All our projects are designed in 3D where we use the computer 3D model to view the performance of our building at various times of the day at different dates of the year.
Generally in the Brisbane, Gold Coast, and Sunshine Coast areas, the prevailing summer breezes come from the north-east in the majority of instances but depending on the topography that may change. If our clients have just purchased the site and do not know this answer, then we suggest that they talk to the locals. If the site is on the coast or canal, there is a good change that blustery south easterly winds occur in the afternoons and can be uncomfortable and needs to be accommodated for in the design especially to your outdoor entertainment and living areas.
With good cross flow ventilation design, it’s simply not enough to face windows towards the prevailing breezes without designing the flow path through and exhaust the breezes out of the building. Shared ventilation between rooms works well when the openings in the walls are aligned correctly and make the leeward rooms much more comfortablewhen these rooms would normally miss out on these breezes in more conventional design approach that you may find in most project homes.
This natural ventilation design technique can be also achieved in industrial and commercial buildings. A very good example being the office building for “Breezway Louvres Office Building” at Coorparoo in Brisbane also using CBUS or similar technology.
The selection of materials is important in the design if we want to combine passive sun control with thermal mass. Ideally in a winter situation, we strive to capture the winter sun to shine onto high thermal mass materials during the day, so that the trapped heat is then released back into the building during evening, whilst keeping the same thermal mass areas shaded in summer to release the coolness of the thermal mass back into the building in the evening. Yes it’s a fine balancing act, and achievable. Thermal mass correctly positioned close to beds and sitting areas can absorb body heat in summer making you feel cooler.
Used selectively it’s worthwhile. Just keep in mind when you add insulation you are effectively creating an Esky. An Esky to work effectively must be closed up and sealed up to keep the cool or warmth in. Then you may question how the warmth and cool is generated to keep it inside this (building) Esky… electrical power… doesn’t make sense does it? Much depends in what climate area the home or work building is located.
In Brisbane / South East Qld / Sub tropical regions where most of our projects are designed, we open up the buildings to gain the benefits of cross ventilation, and as a consequence some of the benefits of insulation are literally blown out of the window. Roof and or ceiling insulation to ventilated roof spaces… yes, but not to all walls as you may be wasting your money and making the building uncomfortable in summer by trapping the heat…. not a smart idea in Brisbane where it can be very humid.
With government rebates making it cheaper why wouldn’t you, or at least make provision for it in the design. The trick is to make it less visually offensive.
Depending on the size of the site, location of trees and adjoining buildings, we suggest to our clients to consider having the solar panels at ground level for ease of cleaning and maintenance. These solar panels can be concealed from view and will leave the roof uncluttered. Our 3D solar modelling can confirm if this is possible as an option.
Having your living or work areas face north is ideal but not always possible. Having your best view facing west may be unavoidable, but it’s not a large problem as you may think. It just needs to be controlled and designed carefully to bring that northern light into main living or work areas into the building by alternative design solutions. Western afternoon sun to your views needs an effective flexible solution that we can provide. Our 3D sun analysis modelling will show how this can be achieved let the solution be low tech or high tech.
So How Does One Know if Passive Solar Design will Work in All Seasons of the Year Before the Building is Built?
To design the optimum sun control takes experience and the right software to verify the passive solar design of the building. With over 35 years’ experience and combined with our 3D modelling software, we strive for the optimum economical aesthetic and solar solutions to suit our client’s needs. The beauty of the software we canset the sun for any day of the year and any time of the day, and modify and or change the solar design to assess the best design solution.We can actually see the results on the 3D Model to verify that we have it right. Our favoured times are the Summer and Winter Solstices. We provide to our clients a number of snap shot views of thebuilding at various times of the year, and a fly-around animation on a nominated day and time of the year on CD, so our clients can appreciate the aesthetics of the design, and see how the building performs passively. All this applies to Homes, Renovations, and Commercial and Industrial projects.
Much depends on the orientation of the site to north(in the southern hemisphere), and the correct placement of the living and or work spaces in the floor plan layout, there may be in some instances noadditional costs to achieve good solar design result. To maximise the benefits of passive solar design and combining it with other aspects of sustainable design, there may be a need to have additional northern glazing. In Brisbane we recommend that we use higher ceilings or selected sloping ceiling areas to move the heat up, away and out of the building during the summer months. Depending on the height of the glazing and or additional glazing there may be a need for sun hoods to control the summer sun and or let the winter sunlight into the building. These do come at an additional cost, but the average payback period is approx 5 years, or 20% return on your passive solar investment. As the word suggests…being “passive”, there are no moving parts and therefore no power is required to do the job forever. It’s a once only cost.
We were selected by a national company “Bondor Insulliving” to design their bench mark home entirely out of their insulated panels with the look of a rendered home. The home can be viewed on “Insulliving “web site. This project was also subsided by the Queensland State Government for an affordable housing solution. The design is currently being occupied by a family of 4 with the home having 100’s of sensor monitors to establish the energy efficiency of the home. This monitoring and reporting is being undertaken by the Qld University of Technology. The QUT study will last for next few years. With results to date all are confident that the energy efficiency will be outstanding with some impressive results yet to be released. The home won a HIA award for building innovation in 2012 for the speed the building can be erected and is being replicated throughout Australia, PNG and soon throughout the rest of the world.
In some instances, absolutely, but retrofitting usually cost more.
Sola-Tubes or the like, are very cost effective for additional light at about the same cost regardless if in a brand new building or an established building. Changing window types from sliding to louvres can be very expensive retrofit, so is adding more northern windows. Sun hoods in most cases can be in most instances easily fitted without a great cost blow out; they just need to be positioned correctly to ensure you get the maximum benefit of your investment. Changing to the glazing to solar glass or solar film on the western side of the building may be considered a cost alternative solution in lieu to a veranda or screening.
Yes to a point to about 70% of its potential. High ceilings, additional northern glazing and louvres come at an initial cost impost, but if you intend to live and work in your building for the next 5 years or so, it’s worth seriously considering going to the next level of design and enjoying your home or workplace to retrieve your cost return (i.e. the payback period).
Yes to a point without costing a modelling arm and a leg, but they certainly can be improved a lot without making major and costly renovations. It’s a case by case assessment.
Air conditioning seems to be a dirty word these days, but when the temperature reaches in the high 30 ‘s and 40’s and in the absence of cooling breezes, and with the fans only pumping hot air, we believe that our clients should have an opinion to gain relief, and that opinion we call the “The give up switch”. With modern ducted air conditioning systems owners can nominate which zone or zones they wish to have air conditioned. In all other times let the design work for you passively without air conditioning without you spending a cent.
Regardless of the orientation to north, all of our clients who have embraced the above have all remarked that they their homes or workplaces (commercial and Industrial) are cool in summer, warm in winter and very comfortable throughout the year with the bonus of enjoying smaller power bills. It’s all very possible as it’s all by the design of the building; it’s not just by chance.
Underwood Centrepoint, 2962 Logan Rd. and corner of Welch St.
Underwood Qld 4119 Australia
Ph: +61 7 3841 3200 | Fax: +61 7 3841 3327 | osmandesign.com.au