Insulation in your house saves heat loss in winter and cools in summer. Categorically! So if that is the case, why aren’t homes in Australia automatically designed to insulate or suit the climate as they are in some countries? In the Arab nations, houses are topped with a wind tower that keeps the dry air circulating. In Spain and Mexico, they have Cupolas, but in the latter, the wet season means the windows need to be closed so the breeze effect is lost. However, the hot air rises into this space and eventually is lost through the bricks of the dome. Mud houses are usually made with ultra thick walls and in some African nations, the thatched roofs breathe. The triple-front brick veneer or MacMansion is generally a poor design insulation wise and it is considered an ‘add-on’, something that doesn’t make sense in the extreme temperature range of most of Australia.
In the rest of the world, some houses are designed with grass or cactus on the rooftop the ultimate protection from heat as the plants and substrate absorb the sun’s rays before it gets to your actual roof. Of course, you need to know that your roof has been built to be solid enough to take the weight of the soil or scoria and that it is waterproof. Black tar paper, impermeable paint and a drainage system sloping to a down pipe is an effective combination.
If you are going for a green roof (grass or cactus that is!) be sure to check your individual climate. For instance, cactus would be no good if you have snow or extreme cold. You may like a couple of mountain goats to keep it trim, but then an electric whipper-snipper works quite well.
At the moment, the Australian Roof Insulation rebate will give you a discount of up to $1,600 which means that most eligible home owners get ceiling insulation for free. This can be the standard blow-in mix but I am not a fan of that as it leaks dust and can burn if you have pin-lights. Asthmatics should steer clear of this. Pink batts, when carefully placed, are much better to work with if, say you need electrical work done later. The choices are quite broad so do your homework!
The table linked below provides an overview of most of the available insulation forms, insulation materials, their installation methods, where they’re applicable to install in a home, and their advantages.
| Form | Insulation Materials | Where Applicable | Installation Method(s) | Advantages |
|---|---|---|---|---|
| Blanket: batts and rolls | Fiberglass Mineral (rock or slag) wool Plastic fibers Natural fibers |
Unfinished walls, including foundation walls, and floors and ceilings. | Fitted between studs, joists, and beams. | Do-it-yourself. Suited for standard stud and joist spacing, which is relatively free from obstructions. |
| Concrete block insulation | Foam beads or liquid foam:
Vermiculite or perlite pellets |
Unfinished walls, including foundation walls, for new construction or major renovations. | Involves masonry skills. | Autoclaved aerated concrete and autoclaved cellular concrete masonry units have 10 times the insulating value of conventional concrete. |
| Foam board or rigid foam | Polystyrene Polyisocyanurate or polyiso Polyurethane |
Unfinished walls, including foundation walls; floors and ceilings; unvented low-slope roofs. |
Interior applications: must be covered with 1/2-inch gypsum board or other building-code approved material for fire safety.
Exterior applications: must be covered with weatherproof facing. |
High insulating value for relatively little thickness.
Can block thermal short circuits when installed continuously over frames or joists. |
| Insulating concrete forms (ICFs) | Foam boards or foam blocks | Unfinished walls, including foundation walls, for new construction. | Installed as part of the building structure. | Insulation is literally built into the home’s walls, creating high thermal resistance. |
| Loose-fill | Cellulose Fiberglass Mineral (rock or slag) wool |
Enclosed existing wall or open new wall cavities; unfinished attic floors; hard-to-reach places. |
Blown into place using special equipment; sometimes poured in. | Good for adding insulation to existing finished areas, irregularly shaped areas, and around obstructions. |
| Reflective system | Foil-faced kraft paper, plastic film, polyethylene bubbles, or cardboard | Unfinished walls, ceilings, and floors. | Foils, films, or papers: fitted between wood-frame studs, joists, and beams | Do-it-yourself.
All suitable for framing at standard spacing. Bubble-form suitable if framing is irregular or if obstructions are present. Most effective at preventing downward heat flow; however, effectiveness depends on spacing. |
| Rigid fibrous or fiber insulation | Fiberglass Mineral (rock or slag) wool |
Ducts in unconditioned spaces and other places requiring insulation that can withstand high temperatures. | HVAC contractors fabricate the insulation into ducts either at their shops or at the job sites. | Can withstand high temperatures. |
| Sprayed foam and foamed-in-place | Cementitious Phenolic Polyisocyanurate Polyurethane |
Enclosed existing wall or open new wall cavities; unfinished attic floors. |
Applied using small spray containers or in larger quantities as a pressure sprayed (foamed-in-place) product. | Good for adding insulation to existing finished areas, irregularly shaped areas, and around obstructions. |
| Structural insulated panels (SIPs) | Foam board or liquid foam insulation core Straw core insulation |
Unfinished walls, ceilings, floors, and roofs for new construction. | Builders connect them together to construct a house. | SIP-built houses provide superior and uniform insulation compared to more traditional construction methods; they also take less time to build. |
Table from: http://www.energysavers.gov/your_home/insulation_airsealing/index.cfm/mytopic=11510
A great resource if you are interested in green roofing is the Green Roof Directory, it contains a comprehensive list of professionals in the field.
FytoGreen also supply grassing for rooftop gardens.
A beautiful design of bringing the grass onto your home – Polish architects KWK Promes designed the OUTrial House in Ksiazenice, Poland
A green clearing surrounded by forest was the only context for the proposed small house. Hence the idea to “carve out” a piece of the grass-covered site, move it up and treat it as the roofing to arrange all the required functions underneath. When the whole was ready, the client came up with another request, to create some space for a small recording studio and a conservatory. The latter was obtained by linking the ground floor with the grassy roof through an “incision” in the green plane and “bending” the incised fragment down, inside the building.
This procedure turned the roof into an atrium, as the only way to reach it was through the interior of the house. As opposed, however, to a typical atrium, the newly-created space has all the advantages of an outer garden while remaining a safe, internal zone within the building. This way, a new type of house was created, and its designation – outrial – is to convey the idea of an atypical atrium which is part of both the interior and the exterior of the building.
Found on: http://www.contemporist.com/
