The temperature in Southern Victoria is rarely consistent.
Similar to Mother Melbourne, Mornington Peninsula can turn from blazingly hot to cool in a matter of hours, and in the Winter drop to some rather chilly nights, and only slightly less chilly days.
We can correct for these with powered devices: heaters and air conditioners, but there are ways to cleverly design around such fluctuations in climate so that your home is protected from the extremes, and liveable without drawing too much on the power bill.
Designing homes for heat in Victoria and the Peninsula
The earth exposed to extreme heat can bake and expand, then contract. Plots prone to this effect will need reinforced foundations under the house to cope with this movement in the soil.
To some degree this is mollified by the shape of the land – its slope and direction. An exposed, convex, Northerly-facing plot will dry and bake to a greater degree than one in a valley to the South, especially if it is also surrounded by shady trees.
An effective cooling system in your house can also involve the sub-floor, with vents in the roof to dispense heat while drawing cooler air from below.
Natural shade afforded by trees is also important for its ability to keep direct sunlight off your walls, windows and roof. You may be fortunate enough to have some eucalyptus around your property, tall enough to offer this shade from above without obstructing your view past the branchless lower trunk.
Conversely, you might like the privacy of sight-blocking trees and hedges.
Otherwise, the use of an awning or pergola can keep the light off your windows.
Outdoor features can be used to deflect the sun’s rays away from your windows, and the use of colour can enter into consideration. A westerly-facing balcony, for example, catches the gorgeous sunsets across the bay, but if that balcony is a light colour, say pale wood, then it will reflect light upwards through your windows and into your home. In this case, consider a darker wood stain, and a slatted or otherwise light-blocking balustrade to create shade on the balcony.
If you have a garden outside, then grass, trees and bushes can have a cooling effect, whereas a white-stone feature will not, and a poorly placed pool or water feature will reflect light directly into your lounge.
The facing of your windows is the first obvious factor – large windows that face
North will let in plenty of heat. If you are dedicated to a Northly-facing area (perhaps because the back of your site faces North and you simply must have an outdoor area), then there are several measures available to you.
Deep eaves and extended awnings create shade, and may make for a pleasant protected outdoor area, taking into account the position of the sun to the West in the late afternoon. Clever construction will have these eaves not so deep that they also block out the Winter sun, which you may need for warmth.
Glazing for your windows to the North ought to be of a high Solar Heat Gain Coefficient (SHGC) value to reflect the bulk of the sun’s direct heat away rather than into the house.
For all windows, a low U-value will insulate your windows from transmitting heat when no sunlight is upon them. Double-glazing in key areas will act as a good insulator.
One often overlooked factor in this is the amount of heat that is transmitted by the frames rather than the glass. An aluminium frame can act as a conduit of heat and raise the U-value of the whole window.
Without going into too much detail, there are recommended ratios of window-to-wall that improves
the protection from heat and light transference of the glass. The better the heat-proofing of the window, the bigger the window you can design for.
The orientation of your house to the wind also helps in cooling your house by airflow.
Knowing where the prevailing wind is coming from, especially at night so you can purge the heat in the cooler hours, will allow you to design openable windows on that side of the house, with its counterpart on the opposite side so that the air can flow through the rooms.
Good house design will mean that there are many avenues for airflow from one side of the house to the other, so internal walls line up accordingly.
Internal fans can help with the comfort levels within the house, which won’t cool the house, but will cool the people inside.
Insulation in your roof and walls are a must to beat the heat and cold, but so are their colour and shape.
A flat metal roof will find no mercy from a high Summer sun, and less warming effect from a Winter one.
A peaked terracotta roof will take on the sun on one or two angles, creating a bounce-away reflection on the shady side, and the solid material will absorb the heat that would, on a metal roof, pass right through. The thermal mass will keep dispelling this heat throughout the cooler hours which is sometimes desirable, sometimes not.
Surprisingly for something made of metal, a Colorbond roof works to dispel heat, even when decorated with dark colours. The angle of the roof and corrugation deflects light away, the area beneath makes good heat exchange with the cooler section of the space, and the material does not keep the heat to make nights uncomfortable.
Clever design will also use the physics of warm air rising to create gentle airflow upward, exiting from the top of the ceiling, and replaced by cooler air from below.
Similar designs for a heat flue can be installed on the Northern side of the house so that the hot air vacates upwards before it even enters the interior.
Any object of large mass will retain heat – the more dense, the more mass, the more heat it can draw and store.
To shed heat, some designers create Earth Coupling, particularly making use of the floor slab, as the solid mass of the slab absorbs heat from the house, and conducts it away into the cool earth below.
In Winter, good design can keep a house warm at night, by letting sunlight hit a solid internal wall that will heat it up, allowing it to release that heat throughout the night and giving the house even temperatures. Clever design may involve constructing windows that will allow the Winter sun to hit this thermal mass, but not the more vertical Summer sun, especially with the use of blinds that can be drawn down to a certain height depending on the season.
Stay cool and warm on the Peninsula
After all, with the extremes of weather that the Mornington Peninsula can deliver, the home you love is going to be the house in which you are most comfortable.
Good design will allow you to remain comfortable throughout the year (or throughout the week given our weather!) with minimal energy spent on mechanical heating and cooling.