Sustainability Assessment of a Gateway Home

SUSTAINABILITY ASSESSMENT FOR:GATEWAY CONSTRUCTIONS
PROPERTY ADDRESS: MT PETER RESIDENCE
MT PETER RD, EDMONTON
DATE:
29 July 2010

CONTENTS

1. 0 INTRODUCTION
2.0 PASSIVE SOLAR DESIGN AND THERMAL PERFORMANCE
2.1 CLIMATE
2.2 SITE
2.3 ORIENTATION AND PLANNING
2.4 BUILDING ELEMENTS
2.5 VENTILATION
2.6 GLAZING AND DAYLIGHTING
2.7 INSULATION
3.0 APPLIANCES AND ARTIFICIAL LIGHTING
4.0 WATER AND WASTE MANAGEMENT
5.0 VEGETATION AND LANDSCAPING
6.0 ALTERNATIVE ENERGY SOURCES
7.0 EMBODIED ENERGY
8.0 CONSTRUCTION TECHNIQUES
9.0 CONCLUSION

1.0 INTRODUCTION
This sustainability analysis is of the Takeaways “Jimbour” Design by Gateway Constructions constructed on Mt Peter Road, Edmonton.
The house is located on a 40ha block, which is more than half covered by valleys and ridges of dry and wet sclerophyll rainforest. The property backs on to forest reserve which is being converted to national park. The house is completely self sustainable for energy, water and waste.
Passive design has been achieved through the management of solar radiation, orientation, effective thermal design strategies, utilisation of cross ventilation, and natural heating and cooling where possible.

2.0 PASSIVE SOLAR DESIGN AND THERMAL PERFORMANCE

2.1 CLIMATE
The local climate is warm/hot humid typically experiencing high humidity, low diurnal temperature ranges. It has a high rainfall for three to four months during the wet season and long periods of dry sunny weather throughout the remainder of the year. Cyclone conditions are possible.

LOCAL SUN CONDITIONS
Summer sun
–Rises in SE
–Sets in SW
–Sun at high altitude Winter sun
–Rises in NE
–Sets in NW
–Low altitude

LOCAL WIND CONDITIONS
WINTER – Winds from South & SE
SUMMER- Winds from North to NE & South to SE

2.2 SITE AND CLIENTS
The site is located in Edmonton, Cairns on a 40ha block edged by State forest and National park with the typical vegetation being rainforest and dry sclerophyll. The building pad was selected on a previously cleared area originally used for cane farming so no further clearing was required. The clients wanted to retain all the existing vegetation. Views are to the North.

The clients were a family of 4 who want to live a normal lifestyle but with small to no carbon footprint. They wanted to be self sufficient for power, waste and water.

SITE ANALYSIS

2.3 ORIENTATION AND PLANNING
The building was sited on the edge of a hill and highset to create minimal disturbance to the land. No additional clearing was required.

The long axis of the house is east to west, minimising east and west facing walls. The embankment and vegetation at the rear of the property shade the house from late afternoon sun.

This is the ideal orientation for these conditions. Living areas and bedrooms face to the north. These areas are shaded by deep overhangs and verandas ranging from 900mm to 4600mm which block out the high altitude summer sun from the SE to SW. Winter sun will be admitted to these areas during some daylight hours. Shaded outdoor areas are provided to the north and south.

Services are located to the south and have deep 900mm overhangs to block direct solar radiation from the summer sun.

2.4 BUILDING ELEMENTS

Thermal comfort has been increased through the following strategies:

ROOF

Metal roof with Aircell Glaresheild bubble foil insulation, and air space, System R Value 2.6
-High reflectivity and low emissivity reflective foil, reflects direct downward direct solar radiation
- Pitched ceilings to living, flat ceilings to remainder.
- Reflective Colourbond roof
- Overhangs are typically 900m with 700mm to gable ends.
- Deep roof overhangs to the living and bedroom one areas ranging from 900mm – 4600mm in depth shelter walls and windows from direct solar radiation
-Light coloured to reflect solar radiation with roof ridge ventilation

WALLS

Timber Stud with weatherboard lining exterior, sisalation reflective foil, air space Aircell Glaresheild bubble foil reflective insulation , particleboard interior lining
-System R Value minimum 1.61
-Pitching Height 2.7m, typ. overhang of 900mm greater than ¼ of pitching height (above compliance with BCA Energy Efficiency provisions).
-Low wall system embodied energy at 227MJ/m2
-Renewable and recycled resources
- Fulfil cyclone requirements
- Well considered placement of walls and well shaded by 900 overhangs, and deep verandas. Shaded to the south by mountains in late afternoon. Excess heat is removed through night flushing of buildings.
- Breathable wall system (with no noggings to encourage air flow) draws in cool air from under house through metal vents which cool wall and roof space. Hot air is expelled through roof vent (see ventilation).
-Light to Medium coloured external walls reflect heat.

FLOOR
Light coloured timber Boral Silkwood Spotted Gum on particle board sheeting on H3 treated timber LVL beams and timber bearers on galvanised posts. Tiles to wet areas
-R Value 0.3
-Particle board flooring 60% plantation and 40% recycled content
-Spotted gum flooring sourced and manufactured in Australia from sustainably managed and legal resources and meet Australian forestry standards.
- Deck timbers meet AFS standards.
- Timber deck areas shaded for north facing outdoor living.

2.5 GLAZING , SHADING AND DAYLIGHTING
Living and bedroom sliding doors and windows are shaded by overhangs and verandas to the North ranging from 900-4600mm in depth providing excellent shading from direct solar radiation.

Boral grey glass windows were used in combination with aluminium louvres. These windows have excellent thermal performance with low SHGC of 0.54 and a u value of 6.3.

Adjustable louvres and sliding doors and windows used throughout for control of daylight, ventilation and night flushing
All window and doors well shaded from direct solar radiation by deep overhangs and verandas.

Light coloured internal walls and ceilings reflect daylight, reducing the need for artificial lighting.

Large openings to living areas to allow natural daylighting, eliminating the need for artificial lighting during the day with the exception of the bathroom areas.

GREY TINTED GLASS WINDOWS

2.6 VENTILATION
Local summer breezes from north to north east captured and filtered through large openings to the north.
-Summer breezes from the south to south east will be captured and filtered through the living area through large openings to the south.
Open plan living areas to facilitate breeze flow
- Cross ventilation system along NS and EW axis as shown in diagram overleaf.
- Breezeways separate living and bedroom areas and encourage airflow throughout the residence.
- Adjustable vertical shading fins promote cross ventilation in bedroom areas. See below.
- Large openings to shaded verandas.
- Fans installed in bedrooms and living areas (1200mm) help to circulate air.
- Narrow building forms, extensive adjustable cross ventilation.
- Wind accelerated through well placed and sized openings
- Bathrooms- naturally and mechanically ventilated
- All the buildings are naturally ventilated and use no air conditioning
- Temperatures and thermal comfort are pleasant all year round
- Breathable wall system and roof ventilation utilise the stack effect to flush hot air from the building elements and eliminate the need for airconditioning. See diagram overleaf.
- The house is highset allowing for underfloor ventilation to cool the building quickly.

2.7 INSULATION

A double layer insulation system is used in the walls consisting of reflective foil sisalation under the weatherboards, an air gap, Aircell Glareshield bubble foil insulation and internal particleboard lining. Aircell product is clean, fibre free, easy to handle, non-toxic, resistant to harsh environments, durable and is virtually maintenance-free.
The breathable wall system utilises reflective foil and bubble foil insulation in combination with internal wall linings braced by particleboard with no noggings to allow walls to breathe and keep cool. The manufacturer states that clients have noted a 3-5 degree reduction in internal temperatures through the breathable wall system. The approximate R Value of this system is 1.6, though actual R value is likely higher as the breathable wall system would increase this value.
Aircell Glareshield bubble foil insulation is also used under the roof and works in combination with the internal air gap and roof ridge vent to provide an approximate R Value of 2.6.

2.8 INTERNAL AIR QUALITY

Gateway constructions has had conducted recent benchmark tests on their Takeaway Buildings which returned a result an air quality of 44g/m3, with safety levels set by Federal Government at 100g/m3, this places Takeaways well below safe levels.
Where possible, Gateway constructions utilises low emitting finishes.
The construction of components and cutting and packing of materials off site reduces on site pollutants. Special sawdust filters catch sawdust from the factories timber cutting machinery so that internal factory air quality is maximised. This sawdust is recycled for mulching of garden beds. The majority of the construction work takes place outside in an open ventilated area.
The highly ventilated system of the designs which incorporates the breathable wall system, wall vents, roof vents, ceiling fans, breezeways mean that fresh air is constantly entering the home clearing pollutants from the residence This ventilation system also reduces the growth of mould and fungi.
The particleboard used is covered and sealed by laminates in the kitchen joinery and painted in the case of internal walls. Ongoing independent and NATA laboratory test results confirm formaldehyde emission of Laminex particleboard at below 1mg/lt using the Australian standard testing method. See Appendix A for Laminex test results for particleboard formaldehyde emissions and VOC levels.
Termite barriers are used that are made from stainless steel instead of chemical barriers.

3.0 APPLIANCES AND ARTIFICIAL LIGHTING
APPLIANCES
Appliances have been chosen to use as little power as possible to reduce demand on the solar power system.
-Gas cooktops and ovens have been utilised and use half the energy of electrical models.
- Energy efficient Fisher and Paykel fridge uses only 200W to run.
- LED Sharp TV lowest energy use model selected by client
- Bosch dishwasher - lowest water and energy consumption available on the market
- Bosch vacuum cleaner - lowest energy consumption availableFisher & Paykel washing machine for low water consumption.
- All appliances switched off at wall when not in use.
- Energy monitor installed in living area to monitor and control usage.

ARTIFICIAL LIGHTING
- Fluorescent lights used throughout
- Lights switched off when rooms are unoccupied
- Excellent natural daylighting reduces the need for artificial lighting
- Light coloured internal walls and ceilings reflect diffuse daylight reducing need for artificial lighting.
- Average CFL produces 34kg of CO2 per year compared with 146kg per fixture for incandescent lighting and cost only 0.5c per hour.

VARYING AND ATTRACTIVE FORMS OF FLUORESCENT LIGHTING USED

4.0 WATER AND WASTE MANAGEMENT

All waste and water is harvested and treated on site and has no impact on the environment.

RAINWATER TANKS
The household is fully self sufficient in their water use with rainwater harvested on site and collected in two 110,000 litre tanks. Water is collected from the house and garage. The tanks consist of a polyethylene 5 layer Aqualiner membrane inside a Colourbond tank. There are numerous filtration systems with metal leaf gutter guard, tadpole filtering system to drainage pipes, first flush diversion and filter at tank. The tank water is pumped back to the residence for all washing, drinking and showering and was filtered before use. The overflow for the tanks is fed back to the adjoining creek. See photo below.

SEWERAGE TREATMENT SYSTEM
All black and grey water is treated by a Biolytix sewerage treatment system. The runoff is then irrigated via drip feed to the lawn below.
Biolytix systems use 90% less energy than other waste management systems, and are odourless and have a safe and waterwise irrigation with no risk of pathogen exposure. They also can be used to treat household waste rather than landfill or composting. There is negligible methane emitted giving good air quality and chemical free treatment so that no potentially hazardous chemicals are disposed in the garden.

ENERGY EFFICIENT TAPWARE
All tapware is AAA rated or higher and Novelli showers were used which have a 3 star 9Lt WELS rating. The toilets are dual flush Raymor with a 6/3L flush and a 3 star rating. This tapware will save more than 50% of the amount of water used in a standard older style home.

DRAINAGE AND WATER MANAGEMENT
On site water is diverted around the residence using a drainage trough. On site water is retained through the planting of drought resistant lawns and native plants. Minimal hard paved areas and the house being highset mean that on site water is retained and returned to the water table.

5.0 VEGETATION AND LANDSCAPING
The building site is located in a cleared area surrounded by state forest and national park. The area was previously cleared and used as a cane farm. No additional clearing was required. A flat pad was created for the garage and shed and the excavated earth transferred to the front of the residence to the wastewater irrigation area.

The house is highset and creates minimal disturbance to the natural landform.

Drought tolerant lawns and native plants have been used to reduce the demand on water. Rainwater is harvested from the roof of the main residence and garage to be used for internal house use and for watering the native gardens and vegetable garden. Mulching will be used to encourage greater water retention. Native plants have also been selected to attract native birds and butterflies.

A vegetable garden is being installed behind the living area with easy access to the kitchen to provide the household with on site food, further reducing their impact on the environment. A composting system is installed below the floor to be used to fertilise the vegetable gardens.

The Biolytix sewerage treatment system is irrigated to the lawn area to the north of the residence.
All on site vegetation has been retained. All stormwater is retained on site or harvested for use by the residents.

SURROUNDING VEGETATION OF DRY COMPOSTING SYSTEM
AND WET SCLEROPHYLL RAINFOREST

6.0 ALTERNATIVE ENERGY SOURCES

SOLAR POWER SYSTEM WITH BATTERY BACKUP

This system is comprised of 4kW of Kyocera panels with a 6kW Selectronic inverter and battery storage system. The system produces all the power needed on site. A generator has been provided as an additional backup but has not been needed.
The family are very aware of their energy consumption and have an energy meter installed to monitor their usage. The parents both work from their home office in the evening hours so battery storage was an important consideration. Their lifestyle has not been compromised by the use of alternative energy sources.

HOT WATER SYSTEM
The hot water system installed is an instantaneous Rinnai gas system. This was installed to save power and reduce demand on the solar power system. It also has the benefit of being instantaneous thus using less energy than a storage system.

SOLAR POWER SYSTEM

7.0 EMBODIED ENERGY
Gateway constructions aim to reduce embodied energy by utilising green construction techniques and by:-
• Using durable low maintenance materials for long life
• Keeping house sizes down (this residence is 215m2 for 4 persons)
• Materials used in construction are used efficiently to standard sizes and machine cut and offcuts recycled and reused
• Transportation costs have been reduced by producing construction components in centralised factory setting
• Avoid wasteful material use
• Paints and other finishes are used over a number of jobs reducing wastage
• Giving preference to materials manufactured using renewable energy sources
• Choosing suppliers with good green certifications and practices.
Embodied energy of construction components:-
WALLS: Timber Frame, Fibre Cement Weatherboard Wall system2
FLOORS: Elevated timber floor 227 MJ/m²

293 MJ/m²
These compare with alternative construction types in the Cairns area such as Concrete block wall construction at 465 MJ/m² and 110mm concrete slab on ground at 645 MJ/m².

www.jameshardie.com.au
www.yourhome.gov.au

8.0 CONSTRUCTION TECHNIQUES

GATEWAY MANUFACTURE ENVIRONMENTAL CONSTRUCTION PRACTICE
Gateway manufacture is committed to best environmental practice and is continually improving their sustainability in both material selection and manufacture. They use standard designs and construct both on site and at their factory. They also manufacture and finish their own joinery.
Floor areas are kept to a minimum to reduce the environmental footprint. Constructions prices are around $1440 per square metre showing that environmental design and construction canaffordable. Construction time is minimised providing further savings as all components are pre-cut and assembled by experienced buildings, tradespersons and labourers.
Gateway has a range of steps that they go through to reduce waste in the factory. On the design side, standard designs are used and all of their wall systems are worked to a grid, this grid allows them to work everything to standard wall sheet material sizes and also position openings accordingly. They then input theses sheet sizes into an automated saw which calculates a best case scenario with minimal waste, the waste produced from this is then reused for gable brace sheets, or cut down for back blocking or nesting plates.
As well as producing these lists for their wall sheeting they also provide cuttings lists for all other factory processed materials. These include, steel, timber studs and LVL’s. This then helps them to calculate the most efficient way to order and utilise all materials for a job. Again waste from LVL’s are reused as blocking pieces in our floors and studs as spacer blocks in walls or nogs for plumbing.
The sawdust produced is filtered and collected and reused as mulch for vegetated areas around office and employees homes and in some cases landscaping for our built projects. They aim to minimise transportation to site by storing some of the materials inside the modules or on the same truck as wall pallets.
In the office Gateway also adopt green measures with shredded documents recycled to local pet stores for their animal enclosures and double side printing of paper for plans and other documentation.

MT PETER RESIDENCE
Materials for the Mt. Peter residence were all cut on site and flat packed and transported to the site where they were assembled by the Gateway constructions team.
The majority of the material used is timber or composite timber product which is a renewable resource with low embodied energy. The only steel used is for the roof and posts. A small amount of concrete is used for the footings.
Timber products used in framing were manufactured from a combination of plantation (60%) and recycled (40%) timbers. Flooring is Boral Spotted gum which is harvested from sustainably managed forests.
Laminex Particleboard used throughout as wall and floor lining and structural bracing is certified by Good Environmental Choice Australia (GECA) and is part of the Greenfirst range produced by Laminex.

GREEN FIRST PRODUCTS
Product
GECA Certified
IEQ-11/13 Volatile Organic Comps
IEQ-12/14 Formaldehyde Minimisation
MAT-7:
Joinery
MAT-11/8
Sustainable Timber
E0 Particleboard STD and Moisture Resistant
Source: Laminex
All Laminex fibre sources originate from plantation forests in Australia, with the vast majority being from softwood plantation and sawmill residue. They have no chemical termiticide and insecticide additives applied to the wood.
Walls are clad with Hardies Primeline weatherboards which are resistant to damage from moisture, rotting, termites and fire, increasing their longevity. They are produced at the Hardies factory with recycled product off-cuts from the manufacturing process used in all three fibre cement plants. Over half of all batches incorporate waste mix slurry. Process water is recycled at least four times before it is treated and released, significantly reducing the overall water demand of the process which currently relies on just 25% of mains water.
Insulation is Aircell Glareshield bubble foil insulation combined with reflective foil sisalation which is one of the most beneficial product ranges for improving energy efficiency and reducing greenhouse gas emissions. For every 150 square metres of Sisalation installed as sarking or wall wrap, between 250kilograms to 500 kilograms of carbon dioxide emissions are saved per annum4
.
A typical Takeaway construction site generates one skip of waste to landfill which is significantly lower than standard construction techniques.

9.0 CONCLUSION
Gateway Manufacture is a progressive organisation, who are continually improving their sustainable building practice.
The combination of factory based manufacture of building components, good environmentally sustainable design and affordable installation put Gateway Manufacture at the forefront of lightweight environmental construction in the Far North Queensland region.
The Mt Peter residence is an excellent example of a fully self sufficient environmentally sustainable dwelling with no carbon footprint. The home uses passive solar design, excellent ventilation and insulation, low energy use appliances, water and waste management, low embodied energy and alternative energy sources to create an environmentally sustainable dwelling.

www.greenatheart.com.au I info@greenatheart.com.au I PO Box 995, Smithfield, QLD, 4878 PAGE 21
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