Collins And Turner Architects, Australia envisioned key steel features that can be harnessed for this site:

• it allows construction of lightweight buildings that can ‘breathe'
• its ability to ‘touch the earth lightly' in locations of poor ground conditions
• the possibility of using recycled steel and the recyclability of the material at the end of the buildings' useful life
• The design concept is characterised by four main foci:
• Narrow floor plates and breezeways
• Minimisation of solar gain
• Formation of pleasant and secure semi public spaces
• Construction system utilising on-site un-skilled labour where possible

The design team at Collins and Turner developed a linear apartment plan form to maximise cross ventilation: the key to thermal comfort in this warm humid climate. All rooms in the apartments are provided with cross ventilation, by virtue of their narrow apartment depth and the inclusion of a unique alcove breezeway. This alcove doubles as the apartments' laundry and drying area and is an external space. Bedrooms and kitchens open to the alcove thus encouraging cross ventilation. The layout of the buildings on site gives each apartment access to the southeast and northeast breezes. The cross ventilation of the individual apartments and the use of the open air access stairwells punctuating the buildings allow breezes to permeate the site.

An additional system of solar thermal powered air-cooling has been included in the design as a potential sustainable upgrade. Further consultation and research with the developers and marketing consultants will be required to ascertain its economic feasibility for this site.

The site plan arrangement ensures that most apartments face northeast and southeast. Northern facades are well shaded by balconies and by locating window openings onto a shaded alcove breezeway. Difficult to shade east and

west facing facades and windows are kept to a minimum. Simple steel meshes further shade windows and facades.

The linear plan forms of the apartment buildings act as (perforate) walls which are arranged to form outdoor spaces. These semi-public spaces are secure spaces accessed only by the apartment dwellers. Along with generous stair landings, they facilitate social interaction and heighten the sense of community. The outdoor spaces are to be well planted, to provide sun shading, privacy between - and a leafy outlook from - apartments. Generous balconies (5.6 m²) are included in the apartments, to allow for outdoor eating. Their large size is offset by the slightly smaller apartment area (48m²).

The lack of availability and high cost of manufactured building materials in Brazil coupled with the low cost of unskilled labour results in low cost construction tending to utilise basic site built materials such as masonry. The challenge for this project is to harness the qualities of steel in a cost effective manner. For this reason the construction system proposed is a simple site welded system, utilizing as much local labour as possible. The steel mesh screens should be cheapest obtainable, most likely expanded metal, but further research into the craft capabilities of the local labour force may prove fruitful in the area of woven metal mesh being site produced.

Over the past decade the emphasis has shifted from the construction of individual low energy houses to the creation of the environmentally sustainable neighbourhood. The individual dwelling is important but the main challenge lies in tackling volume housing in existing urban areas, given its impact on our increasing patterns of energy use.

Sustainable housing should ensure a better quality of life, through the combination of protection of the environment, sensible use of natural resources, economic growth and socio-cultural progress. Socio-cultural progress is a particularly important factor and a key element in sustainable development, as it involves empowering communities. A key factor in measuring the success of sustainable housing is the degree of contentment people show in their neighbourhood. Typically about one person in ten is unhappy with their neighbourhood, but in unpopular housing estates, up to a quarter of people express dissatisfaction. The causes for dissatisfaction: fear of crime, poor leisure facilities, vandalism, litter, noise, disturbance by dogs, lack of comfort (visual, thermal, acoustic) and high energy bills. All of these aspects have therefore been taken into account by the Collins and Turner design team to generate a proposal that is committed to sustainability.

Collins and Turner understands sustainability as a process and sustainable development as the product, the process must, in the field of housing address five distinct fields:

• the conservation of natural resources (land, energy, water)
• the sensible re-use of man made resources
• maintenance of ecosystems and their regenerative potential
• equity between generations, peoples and classes
• provision of health, safety and security.

This project team has tackled these issues through the following principles:

• Consideration of macro (warm-humid) and microclimatic (Jiquia) site conditions.
• Reduced dependence on fossil fuel use through minimizing the need for air conditioning use2. As a warm humid climate, minimizing thermal stress is the first principle to reduce energy consumption, by minimizing the needs for air conditioning use.
• Use of renewable energy resources and innovative solar cooling systems1.
• Greater care taken in the specification of building materials, with preference for locally sourced materials, (e.g. tiles-floors from the Recife Metropolitan region; gypsum-partitions from the Araripe region) and also materials with good recycling potential. These along with the environmental benefits, also support local industry and employment, having important social benefits. Encouraging behavioural change through educational signals and posts, monitoring /informing about systems in operation throughout the site (renewable energy use, water and waste systems, sustainable practices and uses).
• An addition to the brief for each apartment: a covered external service/laundry alcove is proposed. This allows apartments to take full advantage of solar and wind potential, minimizing any needs for energy consumption for washing or drying machines. The service area also acts as a breezeway for cross ventilation of the apartments.
• Use of prefabricated or on site cast made components, reducing the amount of waste generation on site.
• Reduction of water operational usage, by introduction of various water conservation measures (rain water collection system and grey water recycling.
• Reduction of private land use (compact and functional units) and maximizing public/semi public uses.
• Provision of recyclable collection systems on the perimeter of the site.
• Waste treatment on site.
• Reduction of car access throughout site, minimizing noise and pollution, along with provision of permeable surfaces for internal roads.
• Minimizing the impact/ noise pollution throughout the site, by appropriate positioning of buildings further away from Av. Recife and facing mostly northeast/southeast. This allows also for better cross ventilation (since the summer breezes in Recife, when ventilation is needed most, comes from November-March from the NE, rather than the annual average (SE);
• Use of building elements which have a cultural and local identity, but with innovative readings which transcends and reinvents the local context (trellis façade, brise soleil system, integrated structural and solar cooling system)
• Creation of front façades/site edges, (private areas facing public street/public spaces) providing safer urban neighbourhoods.
• Urban and building design solutions that increase chances for social encounters, whilst guaranteeing private and flexible solutions.
• Provision of housing that is environmentally and aesthetically valued by the potential users, whilst providing long term capital assets.
• Provision of a safe, accessible, and healthy public environment, with leisure facilities which cater for local users needs and local context adaptation whist providing interesting and innovative internal housing design solutions.

As mentioned earlier, sustainability is a process and is not only concerned with physical issues, it embraces a whole range of social, aesthetic and economic concerns relating to the well-being of the individual and the community. The design team has created a high-density development, with smaller individual units. In the process, energy, water and material use has been reduced by applying specific solutions to housing problems, considering local context and conditions along with social, economic and cultural aspects. The holistic approach applied, and the design solutions achieved are also highly applicable to the priorities, requirements, site constraints and budgets for all local affordable housing. The result is a comprehensive model which connects to and caters for the occupants, to improve their quality of life and is aligned with the rights of the present and future generations.

The most important advantage offered to the occupants of these dwellings is the sustainability of the scheme (in the broader meaning of this term as described above). The focus aims to attract occupants to the development and to create a thriving community there:

• The features including the alcove breezeway and shallow apartment depth which maximise ventilation and therefore thermal comfort
• Orientation of buildings and sun shading to prevent solar gain
• Attractive, safe and secure outdoor and common areas
• Safety and security in both private and public spaces
• Generous balconies
• Optional solar air cooling system