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New Residential Homes

Every design process is unique, and this generic step-by-step guide to the design process is indicative only. The number of steps varies depending on the complexity of the project and whether you’re building a new home, renovating or simply making a few small home improvements.

Step 1: Preliminary research

This first step is explained in detail in Preliminary research, which covers:

  • examining your current home and lifestyle
  • developing your design brief
  • deciding your baseline budget
  • exploring sources of professional advice for each stage of decision
  • familiarizing yourself with the advice in this guide to inform your brief.

Step 2: Site analysis

Visit the site with your designer to do a ‘SWOT’ analysis (strengths, weaknesses, opportunities and threats). This is your first opportunity to work with your designer to see if your objectives align. It can take the form of a paid consultation or can be part of the design contract outlined in the next step.

On the site, consider:

  • climate responsive design and site specific variables
  • orientation
  • cool breeze access
  • solar access
  • views
  • overshadowing by landforms, trees and buildings (site survey)
  • slope (site survey)
  • soil type (geotechnical report)
  • bushfires risks
  • stormwater drainage
  • access and transport
  • services (power, gas, phone, water, sewer).

The designer can make a concept plan and site analysis after the first site visit.

Choosing a site has more information.

On completion of this initial consultation/site visit, have your designer value-add to your brief by identifying possible design solutions that capitalize on the site’s strengths and opportunities, and overcome its weaknesses (e.g. poor solar access) and threats (e.g. slipping soils, fire risk or flooding).

Analysis at this early stage of climatic influences can identify how your site’s microclimate might vary from the generic climate zones outlined in your home.

Compare your designer’s recommendations to those in Orientation, Passive heating and Passive cooling, and ask for clarification if you’re unsure.

Step 3: Brief development, fee proposal and design contract

If your design contract was not signed earlier, it is usually signed at this step.

The brief you began in the preliminary research stage remains a ‘living document’ that is frequently updated throughout the design process as a record of your agreed decisions. It should also form the basis of the designer’s fee proposal. Annex both to your contract with the designer.

Beyond providing an ‘opinion of probable cost’ that typically includes a range of likely costs, designers generally don’t accept responsibility for the final cost of your project due to the enormous range of variables beyond their control. Buying off the plan can increase budget certainty but reduce design flexibility.

Review your preliminary budget and your brief with your designer.

Ask your designer to review your preliminary budget in light of your brief to identify potential problems and suggest strategies to deal with them. Designers generally work within a range of costs per square meter. Size is the major determinant of cost but other variables include preliminaries (e.g. council, geotechnical and engineers fees), site difficulty (e.g. slope, access, fire hazard, wind exposure), the construction system used, number and size of wet areas (bathrooms, laundry and kitchen), services (cost of water, sewer and energy supply) and access (e.g. drive construction, materials transport distances, travel times for trades).

Your designer should provide indicative costs for each sustainable feature in your brief and recommend additional ones that may be relevant for your site or climate. Apply life cycle costing to each item. In many cases, savings on utility bills exceed the additional costs, and often mortgage repayments, for these features. You will be saving money from the day you move in. ‘Quarantine’ these costings in your budget from the outset to ensure delivery at the end.

The designer can estimate the probable cost of the concept.

Each subsequent update to the brief should be agreed to and signed off by both parties as a variation to the contract.

Step 4: Concept designs

Designers often prepare several concept designs to communicate their thinking and allow you to assess them against your brief. They can range from a simple bubble diagram sketch on the back of an envelope, through to hand drawn concepts of form and spatial arrangements. Analyze them in light of the information in the Passive design articles that apply to your climate zone and raise any questions with your designer.

Concept designs can help make initial sustainability choices.

Concept designs should consider construction systems but not lock them in unless they are a fundamental component of your brief. The choice of high or low mass materials and the amount of mass required in floor, walls or roof to achieve thermal comfort varies depending on other design decisions including glass to mass ratios and heating and cooling systems .

Input from a building sustainability consultant or assessor can be very useful at this stage to ensure that every opportunity to achieve high level thermal performance is locked in while the design is still very flexible.

Step 5: Design development

Through discussion with your designer, choose the concept design that best suits your needs. The designer then develops the concept into a preliminary layout. More than one concept can be developed in this way but each additional concept developed may increase design fees.

This important stage usually includes preliminary room arrangements, window opening sizes and orientation, indication of indoor–outdoor flow, furniture layouts and preliminary choice of construction systems. Spend time visualizing your household living in the design at this stage. Revisit your analysis of your current home. Have problems been overcome? Have new ones been created?

The decision-making process for materials selection also progresses during this step as external and internal finishes are considered. Take this opportunity to identify sustainably sourced materials with low life cycle environmental impact.

Prepare your landscape design at this stage. Landscaping makes many critical contributions including shading the building or windows, diverting breezes, ensuring privacy, creating delight and saving water.

A landscape designer can add shade, character and delight to your home.

It is common for designers to discuss the proposal with council planners and inspectors at this stage to identify any issues requiring resolution.

Step 6: Final design

Make your final design and selection decisions of the following matters:

  • floor plan and building form
  • construction systems
  • window type, size and orientation
  • shading solutions
  • external finishes
  • heating/cooling system
  • major appliances
  • water systems, e.g. rainwater tanks and water recycling
  • landscape design
  • interior design and finishes

This stage is often the greatest test of commitment, for both you and your designer, to achieving an environmentally sustainable home.

Final design is often when budget overruns become apparent and cost reductions are then made. This point is usually the single greatest threat to the environmental sustainability of your home because sustainability features are often considered ‘optional’ and eliminated in the trade-off process even though they may have relatively low cost.

These trade-offs are best managed by dividing your project into stages. Features you don’t need right away can be built or added later. Include the sustainability features at the start and reduce your bills from the day you move in. These features are usually less expensive to incorporate in the initial build than to add later. Additional spaces or rooms designed into a total concept at the outset can be added cost effectively when future finances allow.

Changes made after this stage has been signed off will likely add to design costs.

When both parties are satisfied with the design, submit the final design drawing to council for planning approval before design detailing, if a staged approval process is desirable. This approach can accommodate design changes required by council more cost effectively. The alternative approach (combined planning and construction approval) is more expensive if council requires design changes, which need to be made to both sets of drawings.

Step 7: Council approval; Planning and/or construction certification

Straight forward designs on sites that are not subject to stringent planning controls are commonly submitted to council for simultaneous planning and construction approval. One set of plans can address both planning and construction detailing. For more complex designs that challenge the standard approval process, separate submissions can be advantageous. These challenges are often associated with oversized developments that impact on neighboring views or amenity, or are out of character with the surrounding neighborhood.

A statement of environmental effect is commonly required at planning approval stage. This generally seeks an undertaking that your development will have no adverse impact on the local environment and often has a detailed checklist of items to be addressed.

Step 8: Design detailing

In this stage, design and construction details are finalized and documented. These documents typically include:

  • working drawings (details of how the design is to be built)
  • a specification of the materials, standards, finishes and products to be used
  • engineering design and certification.

They (or more detailed versions) are also given to builders when they are invited to tender for the work and form the basis of your contract with your builder.

Final schedules of materials and quality of finishes are documented in the specification by reference to Australian Standards, industry definitions of practice and desired outcomes that are not noted on the plans. Specifications are critical to achieving sustainable outcomes because it is here that sustainable inclusions, practices and finishes are spelled out and linked to the contract.

Specifications support the working drawings.

Specification writing for sustainability is a relatively new skill, and many designers fail to adequately address important items, practices and standards. Builders often claim that they don’t use environmentally preferred materials and practices because their competitors underquote them by using inferior, unsustainable products or by talking consumers out of features such as double glazing, solar hot water and best practice thermal comfort inclusions.

To level the playing field, specify sustainable practices, clearly and unambiguously, in tender documents and draw these (currently) atypical clauses to the attention of tendering builders.

The next stage is the tendering process with builders.

 

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