Build without skip bins

We have all seen it before: a house under construction in a new sub-division or an intriguing renovation underway, but in the foreground is an overflowing skip bin. In it are offcuts of newly manufactured materials, demolished materials screaming out to explain their history and choc milk cartons, partially covered with a dried layer of waste concrete and tile grout. It’s an all too familiar sight and unfortunately, a largely under-considered step in the big picture of building.

How to avoid skip bins

We are nearing the end of our own building project in a small one-way street in inner Fremantle. Our challenge was to build a sustainable house in a long established urban environment. The first considerations about our waste were: “Where are we going to fit a skip bin?” followed by “What sort of things are we going to need to put in our skip bin?”. With these questions presented, we set about affirming our ethos on waste. By deciding to incorporate waste minimisation wholly into our project, we found we didn’t need a skip bin at all.

Deconstruction

First, there was a need to remove the old house from the block. We sourced multiple quotes from demolition contractors to do this job but their prices were based on profits made from salvaged materials. We were sure there was greater value in our old house for us, so we decided to do the majority of the demolition ourselves.

We salvaged about 7m3 of jarrah timber, a house-worth of red bricks, weatherboards, large locally quarried limestone footing blocks, concrete pavers and old fittings like doors, bathtub and basins. Our ethos to recycle was encouraged by the desire to embody the character of the old house into our new one; there’s no better way to do that than with salvaged pieces of the old house.

It took six weeks for Greg to dismantle the house by hand, a method that allowed him to reuse most of the materials in the new house; the brick walls were repurposed as paving (feature image).

It took six weeks for Greg to dismantle the house by hand, a method that allowed him to reuse most of the materials in the new house; the brick walls were repurposed as paving (feature image).

Waste as commodity

Looking at waste as a commodity is one of the best ways to begin dealing with it. We have all heard of the reduce, re-use and recycle adage. All building projects, including ours, need new materials and lots of them. Reducing excess ‘off-cut’ material accumulation, or creating less waste is probably one of the best prongs on the fork to tackle, and most certainly has the biggest impact. This approach can certainly save money in a project’s cost (most commonly borne by the owner). However, the volume of waste and how well it is managed will depend on the extent of your involvement and the commitment of any builders or contractors.

Accurate material orders

Most worksite skip bins contain brand new materials and this seems totally cost-ineffective, particularly to the owner, not to mention their short lifecycle before appearing in landfill. If you are ordering materials for a project, take the time to accurately calculate what is required. If you are unsure how much you need, under order, but be prepared to get a ‘little extra’ at a later stage. This sort of effort saves having to pay for something that you may end up also paying to get rid of later.

Upcycle

We all agree that junk is junk, but it is worth considering that we are not all the same. Some people see value in objects or items that others don’t. The only difference in the junk’s potential is the imagination devoted to it. We re-used our old earthenware sewer pipes by crushing them with a hammer and adding them to the concrete mix when pouring our exposed concrete floor. The results look great and tell a story, while they could’ve otherwise been in landfill.

There is an ever-growing number of people using re-purposed or up-cycled materials, particularly for construction purposes and there are great savings (and amazing results) to be achieved by doing so. Be willing to be flexible with the outcome of the final product. This may require close working relationships with your architect or structural engineer. It’s much savvier to acquire materials you love and shape them into your project than picture something you like and try to find the perfect materials at a reasonable price.

Reduced waste on housing development sites is also possible. The Sociable Weaver team, when building at the Cape developent in Victoria, instituted a site-wide waste system that avoided the jumble of mixed-use skip bins.  Image: Dave Martin

Reduced waste on housing development sites is also possible. The Sociable Weaver team, when building at the Cape developent in Victoria, instituted a site-wide waste system that avoided the jumble of mixed-use skip bins. Image: Dave Martin

Online network

Our project would not have been what it is without the wonders of the inter-web. Countless items, from broken bricks, floorboards, scaffolding, laser level, brick saw and a ute were bought and sold through platforms like Gumtree. Rather than disposing of it when you are finished, consider if someone else may have a use for it, even if you think it’s worthless. It can’t go in the skip bin if you don’t have one.

Acquired for free, our 70m2 of temporary chipboard flooring was passed on two years later, largely unchanged, to a growing family building a bedroom extension, avoiding the bin on more than two occasions.

We did use a wheelie bin

But what about building site waste? Cement bags, brick pallet banding and all that cardboard packaging. How did we manage to do it on our project site? What waste there was, created daily, was sorted and stored in several designated areas at the end of the day.

Each week we had a budget of one council-collected wheelie bin and (unfortunately still the case in our suburb) one recycling bin per fortnight. We got really good at compressing, compacting and being efficient about loading these bins in a calculated manner, putting in them only what was absolutely necessary.

The waste from Greg's build was modest enough to fit in his regular council rubbish collection.

The waste from Greg’s build was modest enough to fit in his regular council rubbish collection.

Waste management pays off

A skip bin on a building site seems more often than not to be an excuse to ignore or neglect the responsibilities of good waste management. Consider what it’s actually going to be used for and ask yourself (and your builder) if it is really necessary. Like us, you may be surprised to find you can manage without one.

Greg’s beautiful sustainable house featured in Sanctuary 40 and online, and regularly opens for Sustainable House Day.

Open source home automation

There is nothing new about building automation; it’s been around ever since the room thermostat was first invented 130 years ago. There is nothing new about sustainable homes either; they too have been around for over 50 years. However automation in sustainable homes is a relatively new phenomenon and has the potential to move low energy consuming sustainable homes into the mainstream.

Sustainable building embraces passive design principles, natural ventilation being one of the keystones of a passive building design. In climate zones similar to South Australia, where early morning temperatures during the summer often fall below 20 degrees Celsius and the coldest time is typically 7am, you need to drag yourself out of bed around 4am to open your windows and allow cool air to naturally ventilate your home. However times are changing and technology is enabling a whole new audience to look seriously at sustainable, liveable homes.

Today’s homeowner generally isn’t looking to interact with their home; they’re accustomed to homes with ducted air conditioning as the primary way to heat and cool, and do not necessarily possess the knowledge of passive design and natural ventilation principles that the target audience of sustainable design were aware of 20 years ago. Today’s homeowner is familiar with the ‘press the button’ approach, especially as manufacturers embrace the internet of things (IoT) and the ability to control lighting, heating and home security remotely via a mobile phone through companies like Google, Amazon and Apple becomes increasingly familiar.

But what happens when you want the ability for all the ‘things’ to talk to each other, when each manufacturer has developed their own ecosystem or proprietary control system? Enter the alternative: non-proprietary or open source control systems, like KNX. This is the core control system that the Corten House uses.

The west elevation of Paul's Corten House shows the original cottage and passive solar addition (with basement under). By integrating the active and passive heating and cooling systems they can maintain the internal temperature consistently between 18 and 24 degrees.

The west elevation of Paul’s Corten House shows the original cottage and passive solar addition (with basement under). By integrating the active and passive heating and cooling systems they can maintain the internal temperature consistently between 18 and 24 degrees.

This home was constructed in 1904 and is a heritage-listed cottage located in an inner Adelaide suburb, typical of so many in Australia’s cities. The home’s orientation is far from ideal, with living areas facing south and poor natural ventilation because of the proximity of other homes that disrupt natural airflow. The decision was made in 2015 to build an addition at the rear. It was carefully designed to create enough high-level north-facing windows for winter solar gain to heat the home through the winter. This scenario is where home automation can come into its own – the new high-level windows were fully automated. Depending on the data from the sensors on the ceiling they can open and close to ventilate in summer and winter. Once the sensors feel the drop in temperature outside, they will open the windows for you, even at 4am. The system can also purge the home of hot air by sucking it out via ducts throughout the home. This ‘forced ventilation’ makes it possible to have natural air flow even in a built-up city environment.

This, however, is just the beginning. The house consists of two parts – the old traditional stone-walled cottage, cool all year round with small windows and a verandah completely shading the north-facing windows in winter, and the new addition, warm and light-filled. To boost the old part of the house and bring it to the required level of comfort, excess heat from the new extension is moved to the old house. This can even be reversed in the summer months using the ‘coolth’ inherently stored both in the cottage and in the new basement that houses the main bedroom and ensuite and is ventilated via earthtubes.

Working with various sensors both inside and outside the home, the KNX system controls various electronically operated flaps or dampers which work in conjunction with electric fans in the ductwork to move thermally moderated air around. Depending on the outside temperature the KNX system will either circulate warmth inside the home or it will ventilate to the outside. It’s even smart enough to shut down the house when there is a heat wave and not ventilate at all if the outside temperature isn’t cool enough.

When this happens the KNX control system seamlessly communicates with the small multi-head reverse cycle air-conditioner to help maintain pre-set comfort levels inside the home. A carbon dioxide sensor is also incorporated to ensure healthy air quality in the basement – again the KNX system controls this.

While maintaining the comfort levels of the home, the KNX control system also communicates with the solar panel array and monitors energy generated, used and exported. It has been programmed to prioritise certain aspects of the home as well. For several hours during the day hot water takes priority for electricity use, unless the comfort levels within the home are not met.

There is of course, much more to it. The automated controls of the Corten House allow its owners to dim the lights, among other features, using one mobile phone app or (soon to be integrated) voice control. In total there are 12 different components in the Corten House that are linked together and controlled by the KNX system, ranging from hot water to smoke detectors. While the house would have remained a sustainable building without the home automation, it would have required considerably more input from its owners. Now it is as easy as pressing the button on your phone, or just sitting back and allowing the KNX control system to do its job. This is the real game-changer, the fact that home automation enhances sustainable design by removing the manual input that has been part of sustainable living for so many years; it’s opening the doors (automatically) to the new and exciting future.

For more on KNX:
knx.org and knx.org.au

Feature image: A full profile of Paul Hendy’s KNX-automated sustainable house is available in issue 41 and Sanctuary online. His use of smart tech in conjunction with classic passive solar design shows the possibilities for marrying old and new, and for enabling passive systems to better suit a range of lifestyles – especially where someone may not be home to manually ventilate a hot house when the cool change comes! Image: Shane Harris

Prefab performers: 16 of the top rating modular and prefabricated homes

In this special feature, we speak with 16 companies offering what can be called ‘prefabricated’, ‘factory’ or ‘off-site’ construction services. We have selected those with a focus on the residential sector and which provide options for high building energy star ratings, renewable materials and cost-effective production.

We provide a summary below. For further details on each company’s offering including price per square metre, construction time to lockup, and details of the projects pictured, please read the full article in Sanctuary 42.

1. Modscape

Modscape_BlairSt_20160823_409-2 300pxModular construction, steel frame

Since it was established over a decade ago, Modscape has seen its business shift from servicing remote and holiday locations with prefabricated modular homes, to delivering the majority of its projects to inner city sites. Modscape can provide structural modules only, through to a “one stop shop” that includes full internal fit-out, landscaping, solar + battery systems and waste water treatment, among other services. It has always used sustainable materials and now takes a ‘closed loop’ approach that has seen it move to using recyclable steel frames for 90 per cent of its projects. Photo:

2. Ecoliv Buildings

A0080088 300pxModular construction, timber frame

Running for over 10 years, Ecoliv Buildings is based in the regional Victorian town of Wonthaggi, and delivers projects around Australia. Its approach is based squarely in sustainability. The company says each of its homes is resource-efficient and combines passive solar design, construction waste reduction and systems integration. Its process focuses on optimising operational performance using modular prefabricated construction. Solar electricity and hot water, efficient lighting and 10,000 litres of rainwater storage also come standard with Ecoliv homes to reduce environmental impact. Photo: Warren Reed.

3. Prebuilt and Pleysier Perkins

Prebuilt_Ocean St_0006 300pxModular construction, steel frame

Starting out 15 years ago, Prebuilt is a veteran in the Australian modular and prefab industry. These days, while about 60 per cent of its work is in the commercial sector, Prebuilt completes about 18 residential projects each year around Australia, offering predesigned houses and custom designs, usually in partnership with architects Pleysier Perkins. “Custom designs are more and more in demand, especially in Sydney where there are often difficult sites and tight planning restrictions,” says Prebuilt’s Laura Batch.
The company uses a modular system: engineered for the specific site and design requirements of the project, the modules consist of steel structural members with traditional timber frame infill. Insulation, cladding, utilities and the entire internal fit-out is also completed in their Kilsyth factory in Victoria. Photo: Tom Ferguson.

4. Archiblox

Archiblox_Flinders_©Tatjana Plitt_2280 300pxModular construction, timber frame

Archiblox opened shop in 2012 and already has the capacity to complete 40 to 60 modular housing projects per year, depending on the balance of bespoke and ‘smart’ designs on the books. “We encourage people to consider our smart designs because we can achieve greater efficiencies with cost and coordination of the build,” says Archiblox founder Bill McCorkell, who’s both an architect and builder. There are at least 11 Archiblox ‘smart designs’ to work from, and each modular building can be modified to suit the client and site; special care is taken with regard to orienting for passive solar design and to capture views without affecting thermal performance. Photo: Tatjana Plitt.

5. Arkit

Arkit_17_Koonya_Ave_237 300pxModular and panelised construction systems

Arkit designs and uses modular and panelised construction. The approach used is determined by which will achieve the best outcome, based on the site. The company uses similar materials regardless of the approach taken; timber frames, well-sealed double-glazed windows, Passivhaus certified ProClima building wrap, formaldehyde-free OSB and high-density insulation are features of each system. As much of the build as possible is prefabricated within the factory environment, with internal wall linings, footings and services connected on site. Photo: Alessandro Cerutti.

6. Habitech Systems

163 Estuary Rd-2 300pxPanelised construction system, using SIPs 

Habitech Systems has developed its own sustainable building components based on an integrated wall and roof panel system. Founded in 2008 by architect Chris Barnett, the company offers full architectural design services, with a strong focus on thermal performance and healthy interiors. Using its own SIPs (structural insulated panels) which include an integrated cladding system, Habitech uses a growing network of local builders to deliver its projects. The science behind the building system aligns with the Passivhaus standard, and Habitech also works collaboratively with other architects. The majority of Habitech’s clients are in Australia’s southern states, but it has also partnered with builders in New Zealand to distribute its product and services there. Photo: Danny Nelson.

7. Carbonlite

20171003_163116 300pxPanelised construction system; supplies building envelopes to builders & homeowners 

Panellite is a prefabricated timber wall, floor and roof system from Australian company Carbonlite. Carbonlite director Burkhard Hansen is a certified Passivhaus builder with international experience in prefabrication. He launched Panellite in 2015 to provide a flexible panelised system that can be used for any design to achieve the Passivhaus performance standard, and the company routinely provides blower door and pressure testing for completed projects. While Carbonlite can provide design and construction services, its primary business is supplying high-quality building shells for builders and homeowners. Photo: Carbonlite.

8. Makers of Architecture

26.6 lightened 300pxPanelised construction system, deconstructable

Wellington-based Makers of Architecture and construction company Makers Fabrication work together and collaboratively with other designers, using digital technology and CNC (computer numerical control) capabilities to create custom designs efficiently. While Makers can work with a variety of construction systems, the Warrander Studio is a great example of the ‘CLT with cladding cassette’ system developed specifically to make the most of their design and fabrication technology. CNC-cut cross laminated timber (CLT) panels provide the structure and interior lining; prefabricated plywood cassettes containing insulation, service runs and external fibre cement sheet cladding are fitted to the exterior CLT panels using pre-routed slots. A timber ‘rain screen’ connects to the exterior of the cladding cassettes, providing the final skin. Photo: Andrew Cameron & Makers of Architecture.

9. Ehabitat

274A9113-HDR 300pxModular construction 

Ehabitat has offices in Hobart and Melbourne and is a firm of five staff and a small factory. There are no off-the-shelf plans, with each building custom-designed to suit both client needs and the site. Passive solar design is embedded in the system, with low embodied energy materials chosen throughout. The prefab approach “allows quick construction, reducing on-site labour costs by up to 40 per cent,” says Ehabitat’s Giles Newstead. “Our modular system uses low-cost, off-the-shelf materials which can be used with no cutting. This means all internal and external cladding (including glass) just ‘plugs’ straight into the frame.” The system is deliberately space-efficient, and there are many clever built-in storage and space saving options included. Photo: Adam Gibson Photography.

10. Ecoshelta

HHPTopPodLookingIn1 300pxModular and panelised construction systems, aluminium alloy

Ecoshelta runs a small architecture-oriented prefabricated modular building practice with workshops in Sydney and Hobart. It has made small, prefabricated buildings for over 30 years, and has experience using solid timber frames, manufactured timber elements, steel and now marine grade structural aluminium alloy. The company has a strong focus on technology, and uses a combination of natural and manufactured products, composite panel elements and 3D-printed materials. It also uses the proprietary ‘EcoCost’ environmental costing system to provide clients with a full life cycle assessment of the raw materials. Photo: Clare Glade-Wright.

11. Impresa House

Sapkota_062_02 300pxPanelised construction system, timber frame 

Impresa House opened its Derrimut factory in Victoria in October 2016, offering precision-cut panelised prefab homes in Melbourne and surrounds. It works to a client’s existing design, and also offers a full design, project management and fitout service as required. The company’s system consists of timber-framed panels braced with oriented strand board (OSB), which are fitted with insulation, external cladding, and electrical and plumbing runs in the factory. “We use traditional, familiar materials, but everything is precision cut using automated CNC machinery,” explains CEO Sean Morley. “The very precise way that it all goes together means greater energy efficiency, fewer air changes per hour, and reduced heating and cooling needs.”

12. MAAP House

IMG_2043 300pxHybrid modular/panelised construction system

MAAP House has been developed with sustainability and attainability as its primary objective. The firm aims to provide contemporary, high quality finished houses that can be built on any Australian house site. It uses a hybrid flat-pack modular system which it says is able to satisfy the broadest range of needs and accommodate aspect, budget and flexibility in floor plan designs and options. Photo: Mote.

13. MODE Homes

NSW - Prefabricated Folding House 1 300pxModular construction, folding assembly system

MODE uses a patented folding assembly system so homes are largely constructed in the factory, folded down for cost-effective transport and then folded back out when they reach site. The system was developed to reduce the prohibitive delivery costs associated with conventional modular construction. Photo: David Curzon.

14. Fairweather Homes

20180203_114819 300pxModular and panelised construction system

Fairweather Homes has been delivering modular homes in Australia and overseas since 1982 and has constructed 400 houses to date. Its focus is architect-designed sustainable buildings using a “sophisticated” low-risk approach to affordable construction. Fairweather’s component-based, off-site fabrication uses locally sourced, low embodied energy materials.

15. Strine Environments

008 300pxModular construction, precast concrete

Architect Ric Butt of Strine Environments has developed over 30 years a new style of off-site prefabricated modular housing. The model integrates architectural design with precast concrete and environmentally sensitive construction to achieve climate-proof homes that provide an alternative to the usual lightweight, thermally poor-performing kit home products. The prefabricated modules have been designed to fit on a truck and can be delivered anywhere. The E-Cubed system uses Utility Modules and Space Modules to achieve flexibility.

16. Valley Workshop

2018-01-20 15.02.44 300px

Panelised construction system, polystyrene-free SIPs

Valley Workshop is a father-and-daughter team run by Penelope Haley with her father Warren French, the company’s principal architect. They employ a number of staff at their factory in Westbury in northern Tasmania and deliver across the state. The firm’s approach is bespoke and unique, manufacturing their own structural insulated panels free of polystyrene. The skin of the SIP and internal grillage system is made from Tasmanian hardwood structural ply, and wall modules are a stud frame built in the horizontal plane in the workshop. Photo: Penelope Haley.

For further details on each company’s offering including price per square metre, construction time to lockup, and details of the projects pictured, please refer to the full 20-page special in Sanctuary 42.