Envirotecture’s design approach is to create a building and landscape that harmonises the needs of the occupants with the forces of nature, to create naturally comfortable and interesting buildings that require minimal external inputs. This requires each building to make a response to its immediate context: the nature of the site, and its surroundings. We call this ‘localness’ – every building should give a big hint as to where it is in the world.
This approach works with all building projects, whether new residential or renovations, commercial, or public buildings.
1. THE PEOPLE: The first step is to gain a clear understanding of what the building needs to do – how it needs to work, and what the budget is. This is usually expressed in a detailed Design Brief, which is prepared at an early stage during discussions with our clients.
2. THE SITE: The next step is to understand what the site is telling us about how it naturally works – where the sun rises and sets, which way the kind breezes blow, where the nasty winds come from, and where the views are. The climate zone and the detailed topography of the site give us this information, which is presented in a Site Analysis sketch. Other influences from neighbouring sites and buildings, roads etc are also captured in this analysis.
3. THE AUTHORITIES: Thirdly, planning controls are summarised to ensure compliance with all relevant codes and policies.
4. THE DESIGN PROCESS: Then the Envirotecture team look for the most appropriate concept design solutions that satisfy these three groups of parameters, which can sometimes be in conflict. Experience, creativity and good science make this most critical step in the design process unique – and each building should be a unique solution to the different needs and challenges of each client and site.
We looks for ways to provide natural thermal comfort, minimise energy and water demand, and maximise the performance yield of the materials selected. Combined, this ensures the building will work well, feel good, and put minimal pressure on the natural world.
We use the following design principles to achieve these goals (we make no secret of them – so even if you employ another designer, make sure these are followed!)…
Thermal comfort - Envirotecture’s 7 principles of passive design
Good orientation determines where living or working areas and outdoor areas can be arranged to make best use of sunlight, daylight, shading and natural breezes.
Appropriate shading devices and/or eaves will exclude the high summer sun and admit the low winter sun (in southern Australia), basically letting winter sun in and keeping summer sun out. In the tropics, an orientation that excludes most sun all year is usually required.
Orientation for cooling breezes and control of direct sun allows passive cooling of buildings, especially when coupled with thermal mass.
Orientation of the building on a site can capture views and respond to security and noise risks. Arrangement of rooms can ensure privacy is kept and pleasant views are maintained.
2. Zoning the floorplan
Being able to zone different spaces within the floorplan can make the building more usable, and allow better control of any energy inputs.
Private, social and quiet areas can be zoned to isolate the functions of the users of the building.
3. Thermal Mass
Thermal mass refers to a a material’s ability to store heat energy – both positive (warmth) and negative (coolth). Typically thermal mass is masonry walls and hard-surfaced concrete floors.
In temperate climates in winter, heat is absorbed from direct sunlight re-radiated at night. In summer thermal mass is protected from direct sun with shading and insulation. At night the building is ventilated to allow the thermal mass to expel the stored heat (night purging), ready for the next day.
In warm or hot tropical climates, thermal mass is of less use, and other techniques come to the fore.
Appropriate shading methods are used to control direct daylight and unwanted heat gain.
Orientation, glazing area, type and arrangement of shading are considered so that shadings devices best suit the building. Shading devices may be awnings, eaves, pergolas, and planting.
Insulation is paramount to prevent heat gain and heat loss in summer and winter. The type and level of insulation is dependent on the climate conditions, construction material and other passive design techniques used.
Because heat travels by different means (radiation, convection and conduction), different types of insulation are used as required. Avoiding condensation in colder climates is also important.
Natural ventilation is the least expensive means of cooling a building. It is important to provide the correct orientation for cooling breezes, unrestricted paths for cross ventilation, vents and openings for purging warm air, and appropriate glazing and openings to prevent unwanted heat gain.
A continuing source of air movement in hot still conditions can be provided with ceiling fans, which are a default strategy in vitually all our Australian projects.
Glazing – windows and doors – has a major impact on the energy efficiency of a building. Typically in poorly designed houses, glazing accounts for more heat loss and /or gain than any other part of the building fabric.
Well designed glazing will provide views, light, ventilation, noise control and security, all at the same time.
Operational energy - lighting and heating
Envirotecture’s buildings are designed to provide passive heating and cooling (see above), thus eliminating or greatly reducing the need for artificial systems. In some commercial or public buildings, the smartest hybridisation of mechanical and natural systems are used to maximise comfort and energy efficiency.
Daylighting is also optimised, thus reducing the hours when artificial lighting is needed.
Water heating is designed into the building at concept stage, using direct solar wherever site conditions allow. Other efficient systems are used where appropriate.
Buildings with low operational energy demands can supply their own energy with the least capital expenditure. Envirotecture designs its buildings around the use of renewable energy on site. This most commonly takes the form of roof-top photovoltaic systems (PV systems) but can also include small scale wind turbines, and co-generation on larger buildings.
Water is the world’s scarcest resource, and no building can afford to use it wastefully.
Sensitive water design is integrated by Envirotecture with the landscape design, and is responsive to the immediate climatic and rainfall patterns. A three level strategy is applied to the design and specification process:
a. minimise demand with efficient design and appliance selection;
b. use water twice where possible with waste water reclamation systems;
c. capture rainwater to make up the balance.
This strategy gives the occupant high quality water, control of their own resource, and can greatly reduce or eliminate demand on dwindling supplies.
Performance on site: Material selection is considered by Envirotecture at an early stage, and again when making product selections and writing specifications. The concept design will rely on the use of certain types of materials in the right places, and will work properly only if these are used as designed.
Impacts off-site: All materials have ecological impacts off site, either at point of source (forestry, mining etc) or at point of processing and manufacture (smelting, moulding etc). Materials must be selected which offer the best long-life performance, with the lowest impact on the environment.
Toxicity: Toxicity of materials must also be considered, for the sake of the building occupants as well as the wider environment. Employers, parents and child-care providers are increasingly aware of their duty of care, but the same principle applies to all building owners. Many common building finishes ‘off-gas’ toxic substances (VOCs – volatile organic compounds). These can be carcinogenic, and have been linked to leukaemia and other serious illnesses. Benign plant based or natural mineral materials are the preferred choice.
Termites: Through the use of non-chemical Minimum Termite Risk (MTR) construction systems termites are kept at bay, rather than using toxic chemicals that leach into the surrounding soil, and may fail to provide adequate protection.
MORE INFORMATION & GOOD LINKS:
You can find more information on related topics, and about like-minded suppliers and companies by following these links…
The best design manual for Australian residential buildings (we know that because we helped write it):
A great source of sustainable suppliers and companies:
A paper on ‘localness’, written jointly by Dick Clarke and Trevor King (heritage consultant, building designer, and thinker) can be found here. Sorry there are no pics, but fear not – there’s a book coming!