Save money by considering energy efficiency early in home design

Early design decisions (even as early as choosing the block and associated building shape) have a significant and often overwhelming impact on a new home or renovation final cost, particularly with respect to meeting energy efficiency requirements. The majority of the cost is locked in during the initial conceptual stages, as correcting early design decisions is significantly more expensive due to the ripple effects on other decisions.

Key points about the impact of early design choices on building cost to meet energy efficiency requirements:

Showing typical relative costs to achieve a 7-star energy efficiency rating at different stages of the design process. The earlier in the process you introduce an energy efficiency advisor, the lower the eventual cost to achieve the required rating.

• High percentage of cost locked in early:

Studies show that up to 80% of a building's total cost can be determined during the early design phases, making these decisions highly critical for budget management. 

• Cost of change escalates later:

Modifying design elements during detailed design, often results in increased costs due to the need to, for example, employ more expensive components, to avoid having to redesign the whole building. 
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• Factors impacting cost in early design:

• Site selection: The site and the building concept generally, have the biggest impact on overall costs. This is not about whether the site faces north, but is about whether the proposed building concept is compatible with the block and its orientation.  
• Building footprint and orientation: The size and shape of the building, along with the orientation of windows relative to the sun, can impact energy efficiency and the need for more expensive components to meet energy efficiency requirements. 
• Window size and orientation: excessively large windows particularly if facing the wrong way have an enormous impact on the cost of compliance. Poor decisions can result in doubling or more the cost of windows.
• Material choices: Early decisions on materials like exterior cladding, roofing, and interior finishes can significantly influence overall cost. 
• Structural Complexity: The complexity of the building’s structure is another critical factor. Intricate designs with complex shapes or elaborate details require specialized skills and more time to construct, driving up labour costs. For example, a complex roof design, can make installing solar more expensive, increase the risk of roof leaks, place more constraints on air conditioning system design in addition to being more expensive. Simplifying the structural design can make the building process more efficient and cost-effective, without necessarily compromising on functionality or aesthetics.​

Benefits of careful early design consideration:

• Cost optimization: By proactively evaluating design options during the initial stages, architects and engineers can identify cost-effective solutions and minimize unnecessary expenses. 
  

• Improved constructability: Well-thought-out design plans with clear details can streamline construction processes, reducing potential delays and rework. 
  

• Enhanced energy efficiency: ​Early design decisions regarding building orientation, glazing, and insulation can significantly influence both the cost of compliance and ongoing energy consumption and operational costs. 

Strategies to manage early design cost implications:

• Matching the building to the block: Whether starting with a block you want to develop, or have a home concept in mind, they need to be compatible. I have recently seen a case where a different building concept would have resulted in a very affordable home, but because the architectural drawings were nearly complete, the cost to meet energy efficiency requirements was significant. Low Energy Home is prepared to offer a free one-hour meeting to address this, even before you buy a block. See also House orientation, more than facing north.
• Detailed budget planning: Establishing a clear budget early in the design process and regularly monitoring against it. 
• Value engineering: Evaluating different design options to identify cost-effective alternatives without compromising functionality. 
• Collaboration between the designer, energy efficiency advisor and contractor: Fostering open communication as early as possible to identify potential cost issues and incorporate constructability considerations early on. As part of the energy efficiency assessment, Low Energy Home is prepared to have a discussion with the client and the architect or building designer at concept design stage to ensure low-cost energy efficiency provisions aren’t designed out at the concept phase. This is particularly important with the introduction of NCC 2022.

To find out how I can help you cost effectively achieve a 7-star energy rating go to Architect and Builder Services. or Contact us

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