What is green building? What makes a builder a green builder?
You don’t even have to search online to see that there is an avalanche of information out there on “green building’ and more than a few Melbourne builders who position themselves as a “green builder.”
Other sites of course are selling sustainable building products. Many of these products are great but how can you tell which ones are right for you and what the alternatives are? A green builder is someone that should know all the options and can advise you on the best way to go for your unique situation.
There is a lot more to being a green builder than just putting in more insulation, having solar hot water and a water tank. The decision to use a green builder can save you both money and mistakes as there are a lot of choices that need to be evaluated on their effectiveness and value and it helps to have real expert advice.
Here is a list of some of the things that you might expect a green builder to talk to you about your home:
Mechanical ventilation. For an asthma friendly and allergy friendly home
as well as energy savings.
Mechanical air ventilation is widely used in Europe and means you can filter out all outside contaminates so you are breathing fresh air 24/7. Things like pollen and pollutants such as carbon particulates (from fires and diesel smoke for example) are filtered out using a carbon filter. The temperature from the stale air is converted into the new internal fresh air using 92 % efficient heat exchange units which can also heat and cool air with the same unit if needed removing the need for extra temperature control in home. This mechanical ventilation uses very low wattage power and can be easily powered direct from solar panels so the ongoing cost is negligible.
Landscape and garden can play a big role
In green building the house works hand in hand with the landscaping to make your home more comfortable, more beautiful and cheaper to run. The great advantage is that the right landscaping and plant choices can deliver a whole range of benefits and produce these long term at no or minimal cost.
- Roof gardens Insulate from cold during winter and heat in summer
- Creation of microclimates for special plants i.e. to enable those that require sun or heat to be grown in colder climates.
- Once established, many native plants need minimal or no, irrigation beyond normal rainfall.
- Gardens watered with grey water or rainwater.
- Reduce weeds.
- Low in maintenance.
- Reduce reflective heat into home
- Act as wind breaks.
- Natural habitat for fauna such as birds & insects
- They can either be highly productive or decorative examples might be using a ground cover instead of lawn that requires a lot of maintenance, fertiliser and water, or some fruit trees in-between native shrubs.
- Native plants have developed their own defences against many pests and diseases. Since most pesticides kill indiscriminately, beneficial insects become secondary targets in the fight against pests. Reducing or eliminating pesticide use lets natural pest control take over and keeps garden toxins out of our creeks and watersheds.
- Using water as a feature to aid in fire protection, water plants, frogs, insect & animals water source.
- Use of fire retardant tree & grasses species as part of your fire plan
- Incorporating zones of native bush for protection of biological diversity.
- Edible gardens to supplement or even replace) parts of your supermarket shopping
- Permanent natural fences for security and aesthetic appeal or animal control
- Use of Permaculture principles such as companion planting to reduce garden maintenance, plant diseases and watering.
Insulation. Things you need to know.
While a green builder should know how to lift an existing conventional house to the best insulation standards as part of a green renovation. In a new home things like the design of the house and the choice of wall structure and ventilation are the biggest factors in getting the best result. In other words there is more to this than just going for the highest rated fibreglass batts.
- Concrete with exterior insulation called: Insulated concrete forms (CIF). These offer the ultimate in insulation performance, fire proofing, soundproofing, long term durability and unmatched strength.
- High thermal mass walls such as mud brick or rammed earth. Old school but low embedded energy and very effective when combined with well designed & effective exterior insulation strategies.
- Reverse brick veneer. Having the bricks on the inside and insulated from external charging from the outside holds heat in winter and cool in summer.
- Recycled low thermal bridge.
Low or no VOC’s or other toxic compounds in your home
VOC’s are Volatile Organic Compounds they are poisonous chemicals that can become a gas at typical room temperatures and seep from adhesives used in veneers, ply beams, trusses, furniture, paints, floor board coatings such as two pack and also mould spores from wet areas need to be considered. They include chemicals like formaldehyde a known carcinogen and can trigger asthma for example. The longer term effect of these entering our skin & breathing them in is not fully known but they have been linked to sick building syndrome. Surely the simple question is “Why would you have your family breathing chemicals & toxins?
These compounds are released more as temperatures rise so if you do not have fresh air coming into your house your ducted heating & cooling return air is just circulating these poisons around and around for you to breathe.
A knowledgeable green builder can advise you ways to avoid these issues
- Minimal use of veneers.
- Natural timber and stone finishes rather than veneers
- Low or no VOC paints & coatings
- Constant air movement through cross breezing
- Special boards used in cabinetry.
- Using internal gardens
- Using special high performance vapour check membranes to move internal due point & remove mould from developing
- Design effective mechanical air systems
Grey water treatment systems
Grey water is water that comes from your laundry & bathrooms as distinct from Blackwater, which is sewage.
Because this water contains some pollutants and nutrients you can’t just pipe it direct on to your garden long term. Your green builder can advise you on the best system to deal with this for your needs and home size.
Using rainwater for toilet flushing, garden watering and your laundry can reduce your total water usage by as much as 40%.
The Davey Rain bank system, for example will automatically prioritise tank water while ever there is water in the tank and switch you seamlessly over to mains when the tank is low.
There are also systems that allow you to use rainwater for the whole of your house. As a green builder we are experienced in the recommendation and installation of rainwater harvesting systems.
Passive heating and cooling to save (or even eliminate) energy bills
Delivering a total result on this is always a matter of the right design for your site and many factors. While you may or may not have an architect an experienced green builder who has seen many houses work in real life can be a help in achieving the best outcome
Essentially all this means is that your house retains a steady comfortable temperature regardless of the season. In a 10 star house you generally have no need to any additional heating and cooling.
This means using the sun to heat the house and design to retain that heat in winter. In summer a passively cooled house uses the cool ambient temperature of the earth to
- The way the house is sited.
- Correct use of windows and eaves
- Building materials insulated from the outside that tend to retail ambient temperature especially in our constant changing Australian climate.
- Room size and design permitting the use of manageable temperature zones
- Taking advantage of micro climates related to level on the slope etc.
- Heated primarily by the sun, but unlike solar-powered houses, which use solar panels to convert sunlight to electricity, passive designed houses capture the sun’s energy in the form of heat, using the design and construction of the home itself to eliminate the need for afuel based or other conventional heat source
- Removing cold drafts, temperature variations from room to room, and, best of all, virtually no heating or cooling bills. It might sound too good to be true, these conditions are expected & delivered for people who live in passive designed homes.
- Design home to be an extremely energy-efficient in which a comfortable interior climate can be maintained without active heating and cooling systems.
- A passive designed house takes the idea a few steps further, adding superior insulation, airtight construction, and energy-efficient windows and carefully controlled mechanical ventilation, cross breeze ventilation as essential components incorporated into the home’s construction.
Especially if you don’t have an architect an experienced green builder who has seen many houses work in real life can be a big help in achieving the best outcome
Green home design
Green home design combines every factor we have listed above. There is no single silver bullet that makes a green home successful. Rather it is a balance of many, many factors that your green builder should be able to guide you on. You can have a large and luxurious house or a very small house and both can be significantly green. If your budget is limited a green builder should also be able to advise you on design principles which will allow you to reduce the overall size of your home without compromising on room size, aesthetics or quality of finishes. The right sustainable design can still look roomy even though its overall size is less than might be expected.
For more information or to talk about your project call Anton Engelmayer on 0418 177 380