Building the eco friendly way - Wall framing commences

The most efficient way for timber wall frames to be manufactured is pre-fabricated in a factory. Waste is kept to a minimum, there are substantial time efficiencies due to no wet weather delays as well as cost efficiencies over frames fabricated on site. Pre-fab wall frames are made in full or part wall sections, bundled together and delivered to site as shown above. All that is left to do is erect them.

You will also note that the wall frames have a blu-ish colour. The colour indicates that the timber has been treated with Permethrin, which is an organic termiticide and provides 25 year protection against termite attack. Termites are are perpetual problem in Sydney and in our opinion you can not protect a timber structure enough from them. Generally we are not in favour of any form of chemical treatment of construction products. However, there is absolutely nothing sustainable about having a timber structure attacked by termites and a house requiring substantial repair before the end of its useful life. The permethrin does not leach from the timber and remains encapsulated in the structure of the wood, so in theory the environmental impact is minimal.


The key to using timber is for it to be either recycled or sustainably forested. In the case of the wall framing timber we are using, as you can see above, it is plantation pine which comes from Australian Forestry Standard (AFS) or FSC (Forest Stewardship Council) certified plantations.


The first wall frames go up. Standing and fixing the pre-fab Wall frames is a little bit like building a house of cards. Each frame is akin to one of the cards and as each additional frame is erected it adds to the overall structural integrity of the house.

In the background you can see the 24,000 litre rainwater storage tank for the house. The aim for the house is to be self sufficient for water, so potable water for bathing, cooking and drinking will come from this tank.


Having spent so much time and effort polishing the concrete it deserved to be protected. Being the great recyclers that we are we came across recycled carpet that had been put out for a Council kerbside clean up. Unfortunately carpet is one of those construction products that seems to always end up as landfill. It seems that no-one has found a way to recycled it. So if we can give it one more use before it ends up there, then all the better. So in the image above you can see part of the main living area floor protected with the carpet.

Building the eco friendly way - Concrete polishing

Now that the concrete has fully cured, we had to finish it to a standard that we are happy to leave exposed as the finished floor. The term polished concrete is actually a little deceiving. The concrete is not so much polished as 'ground' through various grades of 'polishing stones'. Starting with a diamond grinding stone and progressing through to fine grinding stones which are a bit like sanding concrete with sandpaper. The aim for us was to create a concrete surface with a uniform grey colour and some small aggregate exposed.

The shot above shows the grinding in process. Slow and laborious with many passes across the concrete as one moves through the 'polishing stones'. The grinding can be done dry or wet, we chose to grind it wet purely because the cement dust is a health hazard that we could do without.

The image below shows the concrete surface once we had finished 'polishing' the concrete. You can see the uniform colour as well as the exposure of some smaller aggregate...perfect.

From a negative perspective, concrete polishing has the effect of wearing the finished concrete surface, thus leaving the concrete exposed to staining from anything that might be dropped on it. So a sealer needs to be applied to provide a barrier that prevents the spilt red wine from leaving a stain!

Our choice of sealer is a water based sealing compound manufactured in Australia by a paint company called Murobond. We love both them and their stuff. They have a strong environmental bent both in the products they make and their company attitude. All of their paints and finishes are either low or zero VOC, perfect for anyone planning to building green.

After curing the sealer for a week, we will be straight onto the slab and erecting the timber wall frames. Watch for the next post.

Building the eco friendly way - Concrete slab pour

Most people are not aware of the significant carbon impact that the production of cement has. Production of cement accounts for 5% of the worlds carbon. This is a significant figure for what seems to be an innocuous product.

Because cement plays such a significant part in the construction of any building , if one is to truly build green, then it is important to look at ways to reduce the amount of cement used.

And one of the biggest users of cement in construction is in the manufacture of concrete. Greener concrete suppliers have now started to deal with this issue but supplanting cement content with a product called fly ash. Fly ash is a by-product from the burning of coal and makes an excellent substitute for cement. By using fly ash in concrete, what has previously been seen as a waste product now has become a valuable asset.

For this project we have used concrete from a supplier who has replaced a portion of the cement content with fly ash, significantly reducing the carbon footprint of the concrete we have used.


Because we intend to leave the concrete slab as an exposed element, it is crucial that the concrete is finished and trowelled well. Our requirement was for the concrete to receive a near burnished finish. A burnished finish is when the concrete is mechanically trowelled with a trowelling machine, as seen above, until it has cured sufficiently that the blades of the trowel are almost burning the concrete surface due to the friction of the steel blades on the concrete.

We have used a burnished finish because it provides a durable and hard wearing surface to the concrete as well as a subtle surface lustre.

Lastly, and most importantly is the curing of concrete once it has poured. Curing of concrete is one part of the concreting process that is often neglected. However, without proper curing, all of the earlier effort will be wasted. Curing it the process of preventing concrete from prematurely drying out due to exposure to the sun or wind. If freshly poured concrete is allowed to prematurely dry out, it will fail to achieve its final strength and the quality of the surface finish will suffer.

There are many ways to cure concrete, but the main methods are either the application of a chemical compound to the surface, covering the surface with plastic sheeting or permanently keeping the surface wet. We avoid the use of the chemical compound for environmental reasons and the plastic sheeting because it can mark the finished surface of the concrete. So we use a method of keeping wet hessian rolled out across the concrete surface, as you can see in the image above. Typically concrete should be cured for a minimum of 7 days, with up to 30 days ideal. Given that the finished internal floor will be the exposed concrete, we have chosen to cure the concrete for 30 days to ensure that we have the best quality surface finish.

Building the eco friendly way - Concrete slab preparation

Like most concrete slabs, reinforcing bar is required to help give the slab it's strength. And like all material choices that can be made during the course of construction, one can choose to make a sustainable choice or not. In the case of the reinforcing bar we have chosen to use reinforcing bar from a supplier who uses 100% recycled steel. By using recycled steel, the environmental impact of the steel has been reduced. Recycling steel uses a lot less overall energy than mining ore, and precessing it in order to make new steel.

What is more, the strength and quality of the recycled material is the same as the new material.
The photo above shows the steel reinforcing being placed inside the form work for the concrete slab.

Timber wall and roof framing is still the dominant material for house construction in Sydney. Unfortunately this is the favorite food of one of our native creatures, termites. So it is necessary to have some form of termite protection when you build in timber in order to prevent your house being eaten out around you!

Termite protection can take many forms and more often than not involves some from of pesticide. The key is, to avoid spraying termite barriers on the soil and ground around your house. Not only are they toxic for termites, but they aren't particularly good for humans and the ground ecology.

Several new products on the market seek to address this issue by safely encapsulating a termiticide within a 'blanket' a bit like thick plastic, which can not leach the termiticide. These blankets are used to protect around pipes such as the one above, which prevent termites from entering your house by forming a physical barrier that the termites can not penetrate.




To heat the house in winter we have installed a 5 star gas in slab hydronic heating system. For those who don't know what I am talking about, a hydronic heating system is essentially heated water running through pipes, the pink ones in the photo above, which delivers heat to a location, in our case, the concrete slab.

Hydronic heating is very efficient because is works on the principle of radiant heat, which warms objects rather than convective heat which just warms the air. What is more, in slab hydronic heating is doubly efficient because the heat starts at the bottom most point in a room and rises to the top, heating everything along the way. Rather than air conditioning which generally tries to heat the air in a room from the grilles in the ceiling, down. One way is working with nature, heat rises, and the other is trying to fight it.

For in slab hydronic heating to work at its best, the floor should not have an insulating covering such as carpet or timber. So tiles or exposed concrete in our case, tend to be the best.

Above is the manifold which looks after the balancing of the hydronic heating pipework. Put simply, the two white pipes on the left are the flow and return from the gas boiler and the red is the heated water going out to the slab and the blue is the heated water returning back.

The heating system is designed as a closed loop, so the same water stays in the pipework getting heated at the boiler, then going through the red manifold and out to the slab, then back to the blue manifold and then on to the boiler to get heated and start again. Pretty simple really.

Building the eco friendly way - Ground works and in-ground drainage

One of the key requirements for the project was to provide universal access for the clients. This is basically ensuring that as they grow older, they can still get about easily in their house. Keeping the main floor of the house at the one level is key to achieving this. So as you can see above, there has been some minor excavation and filling on site to create a level platform which will become the ground floor and main living area of the house.

The ground floor of the house will be a concrete slab on ground. The main reason behind this was that a concrete floor has excellent thermal mass. To explain thermal mass in simple terms, the concrete slab will be left exposed so that in winter it can absorb the suns heat and become a source of 'free' heating. In summer the reverse occurs, by keeping the slab shaded from the sun, it will become a source of 'free' cooling.


One of the key features of the house is the water saving and re-using strategies. As well as being self reliant for all potable water, the house also incorporates a grey water recycling and re-use system. Grey water is collected from all hand basins, showers, floor wastes and the washing machine and recycled through an OASIS grey water recycling system. The recycled water is then re-used for flushing toilets, in the washing machine and for watering the garden. In the case of the washing machine, the same volume of water will be in a perpetual cycle of use and re-use.

For a grey water recycling system to work however, the grey water needs to be separate from the black water. Put simply, black water is water from your toilet and kitchen sink and grey water comes from all of the other sources. So to keep these separate, two separate drainage systems needs to be installed, one to direct the black water to the sewer and the other to direct the grey water for recycling.

In the image above of the en suite, in the foreground is the waste pipework for the toilet which is being directed to the right to the sewer. In the back ground is the grey water pipework which is picking up the floor waste and hand basin in the middle of the image and the shower at the top of the image. The pipework then continues off to the left at the top of the image to the grey water recycling system. Simple really!

Building the eco friendly way - Recent press

We were very please to receive some recent press about our green building project at Collaroy in the local Manly Daily.

We obtained Housing Industry Association (HIA) Greensmart accreditation for the project and it appears that it is the only accredited house on the Northern Beaches of Sydney.

The HIA Greensmart accreditation recognises houses that are going well beyond mandatory energy and water efficiency measures, such as BASIX in NSW, and are seeking best practice.

We are driven towards best practice in Sustainable building and are very proud to be pioneering the way on the Northern Beaches of Sydney.

Building the eco friendly way - Demolition complete

Demolition, or should I say 'de-construction', of the existing house was completed recently. All materials salvaged from the building were segregated into like materials for easy recycling, or for un-recyclable materials, sent to landfill.

I believe that we managed to recycle around 60-70% of the materials from the old house. Not a bad effort considering that most house demolitions consist of 0% recycled!

The first image below shows in the foreground un-recyclable materials such as PVC, other plastics and some damaged timber which unfortunately had to go to landfill. In mid image is concrete and brickwork stockpiled for crushing and recycling, and in the background is a stockpile of green vegetation that will be sent for mulching and re-use in gardens.


A huge recycled success was the quantity of timber that we managed to reclaim from the old house. Below is just part of the timber that was salvaged. All this timber was sent to a recycling yard where it will be de-nailed and on sold.

I think that we have demonstrated how easily simple structures can be treated in a sustainable way through recycling. With the quantity of materials recycled, the cost to remove the house was no more than if it was all sent to landfill. The only trade off was the increased duration required to 'de-construct' the house rather than demolish. I would put this at around another two weeks.

Having just been through the process of 'de-constructing' a house it does raise the problem that when we build houses, we aren't building them to be easily pulled apart at the end of their life. This is definitely something that the Construction Industry has to change in order to become more sustainable, I know that we will start giving it greater consideration when we build. Green building isn't just about the building of things, it also needs to take into consideration the 'taking apart of them' as well.

The next couple of weeks will have some excavation and ground works and then the in-ground plumbing and drainage will be laid.

Building the eco friendly way - Demolition progress

As you can see from the photos above and below, demolition work has commenced. Progress is slower than would normally occur for a typical house demolition due to the time and care being taken to 'pull the house apart' piece by piece.

House demolition contractors typically take no more than a week to bring in a large machine, flatten the house and then ship everything out to landfill. Every time I see it happen it makes me fume. What a total loss and waste of tonnes of good construction materials and what environmental negligence, sending a house to landfill purely because people can't look past the way they have always done it. This sort of wastefulness wouldn't happen in a developing country.

As we explained earlier, green building isn't just about the building, it is about the entire process of creating a new house. When we started demolition, the key was to reduce the amount of materials that would go to landfill.
Generally, I am happy with what materials we look like being able to recycle.

The images above and below show the inside of the house with the walls and ceiling partly stripped of the plaster lining. All of the wall, floor and roof framing timbers are in very good condition and will definitely be able to be recycled, great news.

With no recycling facility available for used plaster lining it looks like it will unfortunately be sent to landfill.

All of the windows and doors will be salvaged and sent for recycling along with several bathroom and kitchen fixtures and fittings.

Over the next week or so the brickwork should start to come down and be sent for recycling along with the concrete footings.

Building the eco friendly way - Live sustainable house case study begins

Since we blogged a little while ago about our new sustainable house project in Collaroy Sydney, we have had a number of people ask us for more information about what sort of green initiatives we will use and how are we going to go about it.

So we had a bit of a think about the best way to help give people information and came to the conclusion that we would use the house as a live sustainable building case study to demonstrate to people how to go about building an eco-friendly, sustainable house.

So where do we begin?.....we have given you a bit of an outline about the project in an earlier blog post and more details and information will come out as the build progresses.

The new house is being built on a site currently occupied by an existing house, see below. The house was unusable due to it's location on the site and overall condition, so it had to go. So how does one get rid of an old, unwanted house in the most eco-friendly way?


YOU RECYCLE IT!!!! So that is what we intend to do. Having made a thorough assessment of what materials can be salvaged from the existing house we have come to the following conclusions:

• The bricks and concrete can be sent to a crushing plant to be recycled as road base for road and pavement construction
  

• The timber wall, roof and floor framing can be sent to a second hand building materials yard for future re-sale
  

• The windows can be sent to a second hand building materials yard for future re-sale

• The bathroom and kitchen fixtures and fittings can be sent to a second hand building materials yard for future re-sale

It looks like the only materials that we will need to send to landfill will be those that have to be by law, such as the asbestos roof sheeting, and those for which there is no industry re-sale or recycling system in place, such as used plasterboard wall and ceiling lining.

Recycling the house will definitely be a labour intensive exercise. This is probably the reason why the majority of houses that are demolished are knocked flat by a large excavator and sent straight to landfill, it is quick and easy.

So taking the most sustainable approach to the demolition of the existing house will have an effect on the timeline for the project, but in our opinion if we can actually manage to recycle the materials mentioned above , then it will have been worth it. The less building waste that goes to landfill, the better.

Demolition starts in a few days, sign up for regular updates and to follow how things progress...

your abode starts new sustainable house construction in Sydney

Here is an image of our new sustainable house project in Collaroy, Sydney which we will commence building in early 2009. Green building is what we are about and this house typifies everything about our approach to sustainable houses.
The house will be very eco-friendly both in its design and construction. Water and energy consumption for the house will be very low due to the house:

1. being totally self sufficient for potable water. All water for drinking, cooking and showering will be collected on site and stored in rainwater tanks for re-use in the house
   
2. all grey water from showers, hand basins and the washing machine will be recycled through a grey water treatment system and re-used for flushing toilets and washing clothes in the washing machine.
   
3. not having any air conditioning because of the excellent breeze ways that provide for summer cooling
4. having high thermal mass in both the walls and exposed concrete slab for winter warming and summer cooling
   
5. using an in slab gas hydronic heating system for winter heating
6. using low-e thermal glass in all of the windows to reduce heat loss in winter and prevent heat gain in summer
7. having good eaves and sun shading to keep it cool in summer
8. being designed with good orientation and zoning of rooms

But we haven't only considered water and energy efficiency. Occupant comfort and materials sustainability are also high priority:

1. all internal paints and cabinetry will use low VOC products.
2. recycled Australian Hardwood will be used for the stair construction and for the skirting board and architraves around windows and doors
3. any waste created during construction will be separated into differing materials and recycled

This is a very exciting project for both us and our clients and we will post progress photos and updates as we move through construction.