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Zone Housing

Our households and family structure are continually evolving, but often this is not reflected in the homes we live in. Consequently issues arise when the family home outgrows those living in it, or a change in circumstance results in a desire for more space. In both circumstances the issue rests on the perceived inability to have flexibility within our homes.

CODA has a specific interest in issues related to housing and endeavours to find solutions to the growing pressures that stem from our increasing population and changing living arrangements. As a result, a number of our projects delve into the realm of housing prototypes and the concept of elasticity within the home. Broome North, a set of guidelines for housing in the Kimberley town of Broome, looks at this in relationship to a transient and demographically diverse population. Design strategies for the Town of Cambridge propose housing typologies that will allow the Council to reach their density targets as set out by the document Directions 2031. Whilst projects in the Pilbara consider how homes may have a greater level of flexibility to accommodate the fly-in-fly-out population and the possibility of whole families relocating to communities that exist almost entirely as a result of the resource industry.

The concept of ‘zone housing’ is a notable outcome across all of these projects and provides a solution to the lack of flexibility inherent in most housing. Essentially, the concept of zone housing is the incorporation of two independent houses within one single dwelling ‘shell’ to accommodate smaller households. Feasible in larger residences, the zone home can be re-converted into one larger home, as needs change, or when the household grows. This concept can be incorporated into existing homes and is increasingly important in the design of new homes, as is the case within Broome and the communities of the Pilbara. Consideration should be made towards the likeliness of a changing population and how housing could respond in the near future.

Within the Town of Cambridge single houses make up the majority of housing stock, representing around 74% of all housing. Population forecasts show an increase in lone-person and smaller households, whilst at the same time there is a growing tendency for adult children to remain at home for longer. This current combination of changes in household structures must in turn be reflected within new built form. In the Town of Cambridge there is an opportunity to make use of the existing housing stock and large land plots that typify the area. For a smaller household these large blocks are often high maintenance and costly. With its well-established character and attractive streetscape, there is a natural resistance in the Town to change within the established built form. Residents are protective of their environment and reluctant to move away into smaller residences.

Within the housing pamphlet compiled for the Town of Cambridge, CODA considers these factors and proposes a Zone Home option as one of the specific dwelling typologies relevant to the area. This approach would suit much of the housing stock within the Town, most notably within the suburbs of Floreat and City Beach. An important outcome of the zone home is the provision of a portion of the home for rental accommodation, providing the owners with an income source whilst also being able to remain in their homes.

Within Broome and the Pilbara, the driving forces behind the need for a change in residential typologies rests in the diversity of population and influxes in population. Towns within the Pilbara are predicted to experience large increases in population. Port and South Hedland, for example, are expected to experience a 300% increase by 2035, with towns such as Newman, Karratha and Dampier all anticipated to experience population growth in excess of 200%. In Broome the most recent census found that families made up 69.5% of households and that the cultural fabric of the town is particularly diverse. In both instances the driving force for a change in the way we think about new housing lay in the common lack of affordable and appropriate housing. This, in combination with a lack of labour, brings about high rental costs and a dominance of freestanding, single lot homes unsuited to a considerable proportion of the population.

All of these factors, in combination with the substantial demand for housing appropriate for low-income earners, are remedied within the zone home typology. The Broome Housing Guide makes reference to the term, ‘elasticity’, a concept that suggests the stretching and contraction of dwellings to meet the need for both adaptable homes and smaller, more affordable residences. In one instance, a standard 3-bedroom family home may be converted into a 2 bedroom shared house with the additional room forming an independent living space for additional occupants. The same house could be converted to suit a live/work environment or to accommodate extended family within a tight time frame. Homes in the Pilbara are often too expensive to either purchase or rent for those who work in supplementary industries such as retail, hospitality and community services. An increased provision of zone homes, amongst other smaller residences and housing typologies, would be beneficial for these sectors of the population and would provide a better response to population diversity.

Zone homes are a concept that is specifically suited to the broader Australian context, which typically favours larger houses and excessive block sizes. These may be suitable at particular points in our lives but in time households change and the requirement for a large home is often unnecessary, and, in some instances becomes unaffordable. The conversion, or design of a zone home provides the owner with elasticity of living arrangements into the future, as well as the potential for an income from rent whilst providing a greater level of smaller housing stock for those seeking affordable rental properties. It is a relatively simple application that can be incorporated into both new builds and through retrofitting existing homes. Elasticity is something that must be considered as a credible application within our built environment, particularly as we move towards a denser population both in the urban realm and in regional communities.

References

Western Australian Regional Cities Alliance. http://www.waregionalcities.com.au/regionalcities/kalgoorlieboulder/ (accessed 8 September 2011).

Pilbara Planning and Infrastructure Framework, 2011. Australian Bureau of Statistics

Fill and Substructure Study: East Port Hedland

The purpose of this report is to compare costs of alternative methods for raising the ground floor level of buildings on a low-lying area located within the flood plain of East Port Hedland. The site has been identified by LANDCORP as the most likely next stage of residential subdivision in Port Hedland.

Commonly, in Western Australia, a business as usual (BAU) approach is applied to raising site levels, wherein compacted sand fill is introduced to raise ground levels to the required minimum habitable floor level.

CODA’s role, in conjunction with CAPITAL HOUSE AUSTRALASIA Engineers and DAVIS LANGDON Quantity Surveyors, was to interrogate costs associated with alternative housing typologies and various substructure solutions. From this analysis, costs for a comprehensive range of building types, construction types and site-filling levels have been obtained.

The report considers lots being partially raised by filling to minimum ground levels dictated by 1:20 and 1:50 year flood events. Three common sub-structure types, used to elevate the buildings to the required higher 1:100 year habitable floor level, are examined.

A Cost Calculator and series of Comparative Foundation Studies have been prepared to assist in determining and comparing costs (for filling plus sub-structure only) associated with 135 permutations of House Typology, Building Construction Type, Development Building Footprint and depth of Fill.

Intuitively, break-even costs exist between filling and raising buildings via elevated substructures. The report demonstrates that cost optimization is predominately driven by the cost to supply and place fill material, and the total building footprint intensity (i.e. the sum plan area of all buildings as a percentage of the overall site area being filled).

The report provides an exhaustive basis for analysis of costs associated with raising site levels. Furthermore, the model established is suitable for similar interrogation exercises at any site needing to be raised.

During the course of the investigation an attempt to collate local market views on residential housing typologies and construction methods was made.

Research from established Pilbara Home Builders’ websites revealed that the use of suspended floors is not currently favored and that the preferred house types predominantly comprise of a standard steel roof and wall frame construction with a concrete slab on the ground.

The Queensland floods of 2011 generated an extensive review of the response of Architectural, Civil, Planning and Structural design in relation to development in flood plain areas. Our research has collated some of the findings and identified applicable strategies important for consideration when developing in a flood plain. These included appropriateness of building typology and material selection with regards to resilience to water damage and absorption.

For a full copy of the report please email us at studio@coda-studio.com 

Main Image: Flood prone areas around Port Hedland

Human Comfort in the Tropics

The vastness of Western Australia and the variances in its climatic conditions calls for a variety of responses to its developing built environment. What is considered a suitable and sustainable architectural design in Perth will undoubtedly be less effective in Broome or Port Hedland.

Western Australia displays a large diversity of climate zones, ranging from the temperate south to desert and tropical conditions in the north. CODA’s involvement in remote projects within Western Australia has resulted in a substantial body of research and knowledge as to the climatic conditions within these regions. The resultant research forms design guidelines that outline how best to approach new built works. Amongst social and cultural benefits these guidelines essentially promote sustainability through climate-responsive design. Design guidelines for projects in the Kimberly and Pilbara clearly articulate the most effective way to build for comfort, without necessarily having to rely on artificial cooling.

Human comfort is a specific thermal level that is considered universally comfortable. External temperature, air movement and the ability for the body to warm or cool itself to maintain a required 36.9oC work together to influence our perception of comfort[1]. Within tropical climates, such as Broome, an ever-present humidity has to be taken into account. High levels of humidity generally lead to a feeling of discomfort as the increased levels of moisture in the air impede the body’s ability to perspire and cool itself through evaporation. Unlike sunlight and temperature humidity is a factor that is much harder to design for in the built environment, it cannot be controlled through shade as we do the sun, or insulated against as we do for the heat and cold. Instead, ventilation becomes the essential design consideration in controlling the effects of humidity.

The tropical climate of the Kimberly region is characterised by a distinct wet and dry season and warm, humid conditions throughout most of the year. There is also a notably low diurnal range meaning that there is very little variation in temperature from day to night. The Design Guidelines put forward for Broome establish the most suitable built form for comfortable living in the Kimberley. Low mass construction, light coloured external skins to decrease the absorption of heat, reflective insulation and careful positioning of openings to maximise the effect of ventilation [2] are all important in this climate.

In comparison, in climates where there is a broad diurnal range (where temperatures significantly drop at night) thermal mass works effectively in re-radiating the absorbed heat throughout the night. Places with low diurnal ranges, such as Broome, rely heavily on evening breezes to ventilate and so we must design to allow this to happen efficiently. In essence lightweight construction works most effectively, it does not store heat throughout the day, thus eliminating the consequent ‘heat blanket’ as the heat is re-radiated. This ‘blanket’ of warm air around and within the building would impede the cooling effect of any breezes throughout the night. Lightweight construction in combination with the careful positioning of openings to allow for cross ventilation is the most efficient means to providing comfort within a humid climate.

With this in mind the physical orientation of the home is crucial in maximising the effect of breezes. As a guide it is considered that within Broome, for example, the most beneficial breezes are westerly followed by those from the north-west and south-west.  Primary openings should be positioned to capture these and allow them to move through the home with as little obstruction as possible in order to flush warm air from the interior spaces. Focusing the principal living areas with respect to the prevailing breezes will essentially help in reducing the need for air-conditioning within the home.

The tropics are a unique climate because of the humidity factor but, despite this, it should not automatically be presumed that air-conditioning be the only solution for internal cooling. It is most certainly a climate that requires comprehensive consideration and planning, particularly in relation to the materials chosen and their thermal performance. Essentially the key to passive urban design within a tropical environment is to minimise exposure to direct sunlight, and to design openings that ensure sufficient airflow can pass through the whole building.


[1] Queensland University of Technology 2009

[2] Broome North Design Guidelines, CODA/Landcorp

Ageing in Place

Growth in our cities and the subsequent need for responsible developments to ensure well connected, planned and functioning communities is currently a significant subject within Perth where the population is expected to increase by an additional half a million people within the next 18 years[1]. Strategies are now being put in place to combat the urban sprawl that defines our coastline and in doing so create a more contained, well-connected city in which communities are able to develop and flourish. In 2010, the Department of Planning authored a forward thinking document entitled Directions 2031, which suggests broadly increasing density across Perth through the rejuvenation of its urban cores.

In addition to this, Australia’s evolving demographics reveal that, alongside single person occupancy and the growing number of families with adult children living at home, housing situations for an increasingly ageing population need to be taken into account. Advances in health care and medicine have resulted in a population that is not only growing, but ageing as well. According to the Australian Housing and Urban Research Unit, by 2051 the percentage of people aged 65+ will double and those aged 85+ will have quadrupled. These figures demand that we adopt a new perspective on housing developments for aged and dependent people.

In 2011 Coda was appointed by the Town of Cambridge to assist in the review of their Town Planning Scheme and to suggest ways to increase density through infill development. Through this process an awareness of the need for age diverse housing was increasingly apparent and resulted in a specific scheme for a medium density infill development, which focused on the idea of ageing in place. This report discusses the scheme in greater depth and the consequent matters related to an ageing population.

For more information or for a full copy of the report please email us at studio@coda-studio.com



[1] Department of Planning Western Australian Government. (2010) Directions 2031 and Beyond: Metropolitan Planning Beyond the Horizon. Perth: Western Australian State Planning Commission.

 

Karratha Solar Analysis

Karratha is a coastal town in the Pilbara region of Western Australia. The town experiences tropical weather conditions, with hot humid summers and warm winters. Temperatures are high for most of the year, with 232 days per year over 30C. From September until April, average temperatures rarely fall below 30C, and can reach up to 48C (21st Jan 2003).

March is generally the hottest month of the year in Karratha, and it is not unusual to experience up to 4 days over 40C during this time. July on the other hand, is the coolest month with an average maximum temperature of 26.2C.

Due to these extreme temperatures, building design in Karratha requires additional design measures so as to not allow unwanted heat build-up or ingress into the house. The most effective of these is shade. Simply put, direct solar heat gain will occur to buildings and their surrounds unless adequate shading is provided.

In addition to shading windows and walls, it is beneficial in climates such as this to provide shade to any areas of thermal mass at ground level, such as paving and/or concrete (driveways and paths). Materials such as these, with thermal mass, have the capacity to absorb and store large amounts of heat energy over a period of time and re-release that stored heat once the heat source is removed. The re-radiated heat can then ‘blanket’ the house long after the sun has set.

Our Design Guidelines for Baynton West require an 800mm eave to all external walls on new residential properties. This requirement delivers additional shade to all walls and windows compared to standard (450mm or 600mm) eave lengths, and allows shade to surrounding ground surfaces to prevent heat build-up.

To demonstrate the benefits of an 800mm eave, CODA have conducted a solar study of the effect of an 800mm eave compared to a 100mm eave on a house with an eave height of 2700mm. For the purpose of the study, a lot size of 525sqm (15m x 35m) has been modelled, with a 265sqm (11.5m x 23m) rectangular house built on it. Note, the modelled house does not represent a form which is compliant with either the R-Codes or Design Guidelines with regards to setbacks etc, but simply demonstrates the shade provided by a 100m or 800m eave on each of the elevations. The solar study was conducted with a north-south house orientation and an east-west orientation.

 

Our findings are as follows:

1. A North-South orientated house (long-axis running from north to south) with an 800mm eave, is provided:

Summer Solstice: 100% shade to northern and southern elevations all day, with morning solar exposure to the eastern elevation and afternoon solar exposure to the western elevation. Full shade to house at midday.

Winter Solstice: 15-30% shade to northern elevation for most part of day, with 100% shade to southern elevation all day. Morning solar exposure to the eastern elevation and afternoon solar exposure to the western elevation.

Spring and Autumn Equinox: Both northern and southern elevations in full (90% or above) shade all day, including ground shade to the southern side of the house. Morning solar exposure to the eastern elevation, and afternoon solar exposure to the western elevation with both eastern and western elevations in full shade at midday.

 

2. A North-South orientated house (long axis running from north to south) with a 100m eave, is provided:

Summer solstice: 100% shade to northern elevations all day. Varying shade to Southern Elevation throughout the day, peaking at 80% shade at mid-day. Significant morning solar exposure to the eastern elevation and extreme afternoon solar exposure to the western elevation from early afternoon (15% shade at 3pm).

Winter Solstice: Little to no shade (max 5%) to northern elevation all day, 100% shade to southern elevation, including ground shade all day. Morning solar exposure to the eastern elevation and afternoon solar exposure to the western elevation.

Spring and Autumn Equinox: Southern elevations in full shade all day, including ground shade to the southern side of the house. Northern elevation shaded no more than 15% until late evening. Significant morning solar exposure to the eastern elevation lasting until early afternoon, and afternoon solar exposure to the western elevation from mid-day onwards.

 
3. An East-West oriented house (long axis running from east to west) with an 800mm eave, is provided:
Summer Solstice: 100% shade to northern and southern elevations all day, with morning solar exposure to the eastern elevation and afternoon solar exposure to the western elevation. Full shade to house at midday.
Winter Solstice: 15-30% shade to northern elevation for most part of day, with 100% shade to southern elevation all day. Morning solar exposure to the eastern elevation and afternoon solar exposure to the western elevation.
Spring and Autumn Equinox: Both northern and southern elevations in full (90% or above) shade all day, including ground shade to the southern side of the house. Morning solar exposure to the eastern elevation, and afternoon solar exposure to the western elevation with both eastern and western elevations in full shade at midday.

 
4. An East-West oriented house (long axis running from east to west) with a 100mm eave, is provided:
Summer Solstice: 100% shade to northern elevations all day. Varying shade to Southern Elevation throughout the day, peaking at 80% shade at mid-day. Significant morning solar exposure to the eastern elevation and extreme afternoon solar exposure to the western elevation from early afternoon (15% shade at 3pm).
Winter Solstice: Little to no shade (max 5%) to northern elevation all day, 100% shade to southern elevation, including ground shade all day. Morning solar exposure to the eastern elevation and afternoon solar exposure to the western elevation.
Spring and Autumn Equinox: Southern elevations in full shade all day, including ground shade to the southern side of the house. Northern elevation shaded no more than 15% until late evening. Significant morning solar exposure to the eastern elevation lasting until early afternoon, and afternoon solar exposure to the western elevation from mid-day onwards.

 
Conclusion:
While a 100mm eave will provide similar shade to an 800mm eave at midday on December 21st (summer solstice), the additional shade provided by an 800mm eave in the hours prior to and following mid-day is significant: 10% increase in shade to eastern walls at 9am and 35% increase in shade to western walls at 3pm.
An 800mm eave also provides superior solar protection during the spring, autumn and winter months, when the sun is much lower in the sky. Most significantly, a 75% increase in solar protection to northern walls in March, when the temperatures are often the hottest (up to 450C)and the sun is much lower in the sky.
An 800mm eave also provides significantly more ground shade year round, preventing heat build up and re-radiation from external thermal mass surfaces.

ReHOUSING Conference

Following our success in winning first prize for the national competition “Building for Diversity”, we presented our mixed-use development project at the 2006 ReHOUSING Conference in Melbourne.

The competition sought to “provide an opportunity for architects to generate and test ideas for an affordable mixed-use development… (comprising) a variety of accommodation types, together with retail and commercial premises.”

As this was a one-stage ideas competition we worked quickly as a studio to develop the big idea and the visual language of the project.  In the absence of schemes of a similar type having been completed within the office, we relied on a kind of ‘conversational collage’ technique to describe the project to one another – like a hybrid of well known projects draped and inserted over the site.

We saw this conference as an opportunity to reflect on the references that were used as visual and verbal cues during the project and produce a secondary set of collages for discussion.

The site was located on the corner of Newcastle St and Zempilas Lane in Northbridge, Western Australia. An advertising campaign and large billboard on the site enthusiastically reports that “every corner of Northbridge is changing”! – although, to date, there has not been a lot of action on this or the adjoining sites.

It is worth noting that Northbridge has a certain mythology attached to it – as a vibrant multicultural centre , providing culture, entertainment and nightlife to Perth.  In reality this cosmopolitan quality is quite “patchy”. More recently large high end apartments have appeared and there is relatively little density or diversity on the street throughout most of the week. The competition brief asked that the project engender diversity and sustainability through the housing it provided.

Our scheme sought to address this perceived lack of diversity through  the provision of housing that allowed for a live/work model and the addition of communal and commercial spaces at street level. We attempted to attract a mix of creative and culturally diverse residents through these loose fit apartments.  This strategy can be broken down into 3 key moves: Parking and Garden, Tower and Apartments. It also addressed three themes of sustainability: economic, environmental and social/community.

Although we started with density as a strategy, we feel that the urban experience is not a simple by-product of density but that it is created by the arrangement of experiences. The proximity and intensity of public, private and semi public spaces can, for us, create an “urban” experience in as much as it affects how people interact, pass by and engage with one another.

For a full copy of the paper presented at the 2006 ReHousing Conference, please contact us at studio@coda-studio.com

Think Brick

In 2009 CODA won the national About Face Award, an invitation-only, researched based competition run as part of the Think Brick Awards.

We believe that architects are uniquely placed to tackle the issues of homelessness, social housing and community inclusiveness by proposing large scale planning responses in combination with smaller scale, considered architecture and landscape.

The selected site for our scheme is located at the fringe of Mandurah, an hour from Perth. The scheme addressed the region’s growing need for affordable housing and supported hostel accommodation, and integrated it into a community driven mixed-use development. Social housing, affordable housing, commercial and retails space and community facilities mingle around a grove of existing mature Tuart trees. There are community garden allotments, basketball courts on parking lots, vegetable gardens for the communal kitchens, playing fields, playgrounds and spaces for sitting, reading and relaxing.

The Hostel Building contains multiple programs within the building form. Using the Foyer model, young people in need are provided with stable accommodation and support in order that they continue to participate in education, training or employment. Simultaneously, we referenced the ‘Common Ground’ business model which seeks to assist people in work placement and offer them a path to full-time employment through a structured support program.

Whilst a supported social housing model is certainly warranted within the Mandurah region, generally the issue of affordable housing continue to be a critical issue. There are many people who cannot purchase homes yet need accommodation from which to work as a base. These people play a significant role in the functioning of the city, as crucial workforce, as well as adding diversity to the community.

Housing options that address the possibility of flexible live/work arrangements contribute to the activations of sites by ensuring continual activity. Our Think Brick project addresses these opportunities as well as introducing the idea of communal living, a notion of  importance for a workforce increasingly driven by the resource sector that flies in and out its work force.

Munster Grouped Housing Project

This study explored opportunities for housing diversity in Munster, a suburb south of Fremantle, Western Australia. The typical dwelling in Munster is a detached single house on a 600sqm lot.  The study and concept designs have been prepared by CODA for LandCorp and are the result of research and testing to find viable opportunities for multiple housing on a single lot.

The designs also needed to provide demographically diverse and affordable housing options as well as respond to the scale and grain of the accepted suburban pattern of the surrounding area. The designs evolved from an exploration of the ‘maisonette’ housing type which presents to the street at an integrated, suburban-scale built form whilst accommodating multiple units. Whilst the designs respond to the specific site conditions of Lot 45 and Lots 52, 53, 54 of LandCorp’s Mayor Road subdivision, the study is intended to demonstrate the importance of a sympathetic and harmonious response to the site conditions, both physically and contextually.

Multiple Dwelling Opportunities
The new provisions in the amended Residential Design Codes (gazetted on 22nd November 2010) remove ‘minimum site area per dwelling’ controls for lots zoned R30 or greater, thus allowing smaller multiple dwellings to be built in areas where historically only single or group dwellings would have been allowed. Importantly, the new Code enables LandCorp to integrate one bedroom and two bedroom dwellings into subdivisions which previously imposed minimum dwelling sizes of 140sqm or greater. It allows us to consider a range of accommodation for a more diverse demographic than has been possible previously in Munster.

The new Code is more compatible with LandCorp’s two tiered strategy for affordable housing:
1. affordable housing facilitates both housing which is priced for key workers and households on low to moderate incomes, including social housing, and
2. affordable living which seeks to provide diverse, efficient housing stock with equitable access to community facilities and amenity.

Lot 45 can accommodate six dwellings. Lots 52, 53 and 54 would be amalgamated to enable a single lot of 10 dwellings. The dwellings range from 72sqm to 150sqm, each with generous outdoor living areas as well as the shared areas.
The site planning is integral to the success of the individual housing designs and the enjoyment of future occupants. Cardinal orientation maximises north solar access to the interior and exterior living spaces of each unit. The steep contours on the lots allow garages to be located at a lower level to the dwelling entrances, which frees up the shared spaces for landscaping and innovative uses such as a communal vegetable patch, tool shed, barbecue facilities and water tanks.

The floor areas and plans consider the life-cycle scenarios of young singles and couples who might be first home buyers; families; empty nesters; and retirees who might want to continue living in the area where their family home was located. Disabled occupants and visitors are also catered for with a disabled car bay on each lot and universal access to ground level units. The larger units also allow for more independent living for aged or teenage family members as well as flexible spaces which can be used for a home office, theatre room, study, play room or additional bedroom.

Sustainable design
This has also been an opportunity to  test and apply the sustainable design principles which LandCorp actively promotes to the new multiple dwelling code.
The designs address the notion of sustainable housing at four levels: climatic, environmental, social and economic. To be successful, the houses must perform successfully at each level and the design intent must be supported by decisions and practices made throughout the development and construction process.
These concepts for site planning and housing design could be readily adapted to other lots and site conditions. For example, the units could be rotated to take advantage of cardinal north-south orientation. A flat lot could have garaging located on the same level as the dwelling entrances.

Ongoing review
To ensure that the design intent is not lost in the journey from design development to habitation, the development and construction process needs to be guided by ongoing review and assessment by LandCorp and the architect. A checklist of design guidelines would make this process more manageable for developers and builders as well as ensure that there is a consistent and clear interpretation of the intent by all parties.
The Mayor Road concept houses have the potential to make a significant contribution to the quality of multiple housing in Western Australian and can only benefit from developers and builders who share the design intent vision.