Sustainable Home Design

When you are outlaying what may be one of the biggest capital investments within our lifetime — explore our inspiration gallery and blog to see how we deliver value, this is the most stressful, crucial and commonly asked question. Unfortunately, there is no simple answer and is quite often the best example of the old adage “how long is a piece of string?”.

The most beneficial route is to state your budget upfront so we can design to suit. This is where Design Science leaves the competition behind, we are designers, builders and estimators. We understand cost in a manner that non-trade building designers and architects have no relationship with, we know how, and what it takes, to build it! We are invested into providing you a satisfactory result, that includes designing something within your budget range. There is little benefit in approaching design without a budget in mind.

There are a few considerations to make when embarking on a design and build journey. Remember, nobody can tell you how much your project will cost, without knowing all the “ins and outs” and finer details. What you will receive are straight out guesses. As many builders and tradesmen you ask the question too without detailed plans and specifications, is as many widely varying and differing ‘guesstimates’ you will receive. The risk is yours to take, more often than not the final completed project cost will be much greater than the guess you were given beforehand.

Sometimes it is best to start with a ‘concept plan’ only, then engage a Cost Planner/Estimator to give you some budget costs based on that plan prior to proceeding any further. There are literally thousands of dream designs that have been put onto paper at great cost, only for clients to find out that they then cannot afford to build them.

Below are some cost guidelines to consider

Cost has a direct relationship with several revolving factors:

• Location – how accessible is the site, is the land flat, sloping or steep, what is the soil’s reactivity to moisture, is it rocky, where are the services accessed – water, electricity, sewer, internet. How exposed to wind is the site, high, medium or low. What is the climatic location of the site and all these locational factors will this affect both livability, structural strength requirements and cost.
• Size – how big is the project you are envisaging, small, compact, practical, or expansive and luxurious.
• New or Renovation – renovations are most commonly more expensive to construct per square metre than new homes. Is there demolition or site clearing requirements. Kitchens and Bathrooms are the most expensive areas to construct and renovate. Are the existing structures in sound condition and capable of renovating or require re-building. Where are the sewer pipes located.
• Construction Type – Conventional System or New System, lightweight or solid, timber or steel, concrete or joist, bearer & post, single or multi storey. There are many new construction materials on the market that can provide excellent levels of structural integrity, insulation, longevity, sustainability, low VOC and speed of construction. Quite often there is a trade-off between the material cost v labor components and whilst one material may appear cheaper, it will cost exponentially more in labor to install. Another major factor can be cranes, pumps and steel, these can quickly escalate cost of construction.
• Preliminaries – Different projects have different requirements for preliminary investigation and services. Including, Surveyors, Soil Testing, Service Locators, Town Planning, Interior Designers, Cost Planners, temporary utilities, site clearance and excavations. Some may require a detailed measure and production of existing sets of building plans.
• Style – Modern, Minimalist, Contemporary, Hamptons, Queenslander, Federation, Eco, Tiny House, Beach, Passive, simplistic or articulate and complicated. Each has its own positives and negatives when relating to cost.
• Project Builder or Custom Builder – Project Builders are generally large companies with excellent purchasing power and systematic processes. The offer many ‘pre-packaged’ designs and build cost and are generally cheaper per meter square than a Custom Builder can compete with. Project Builders rarely step outside their ‘cookie cutter’ home and will not build to somebody else’s plans or deal with renovations. This is the domain of the Custom Builder, they will build your design or complete your renovation. They have lower overheads and generally complete a higher quality build. A Project Home will nearly always be cheaper than a Custom Designed home, it is a matter of deciding whether you are happy with a pre-packaged design and high volume build quality, or you wish to ‘put your own stamp’ on things and have a generally higher quality construction. Project builders are largely responsible for the energy efficiency disaster we currently have throughout most of Australia, they provide the minimum standard possible. You get what you pay for.

In Summary the following points should be considered prior to commencing your design and building journey. Read our latest articles for more guidance, or get in touch to discuss your project:

• Multi-Storey costs more per square meter of floor than Single Storey
• Lightweight Construction is cheaper than masonry / heavy weight construction (usually more energy efficient too)
• Bathrooms and Kitchens are the most expensive rooms in the house
• Simple Designs are cheaper than Complex and Innovative Designs
• Aluminum sliding windows and doors are cheaper than stackers, bifold and timber construction.
• Timber is cheaper than steel
• Flat clear sites are cheaper than sloped, and steep are the most expensive to build on.
• Renovations may require drawings of Existing Building Plans first.
• Renovations may require third party investigations/preliminaries and costs prior to design.
• It is often a better result to strip a room back to the frame when considering bathroom renovations. Cost of demolition may be a small price to pay to uncover hidden existing faults.
• Project Builders are cheaper per meter square than Custom Builders (so is the quality).
• The greater the level of plan detail and specifications, the greater the accuracy and comparability between quotes from contractors and builders and the more likely they are to even price and complete the job.
• The level of detail and specification will also determine the number of ‘cost surprises’ during the journey and quality of the destination.
• Renovations cost more per square meter of floor than new builds. Kitchens and bathrooms cost more again  relative to other spaces.
• Large span windows, doors and rooms are structurally more expensive and result in greater heat / cold transfer between inside and outside.
• For bathrooms allow a ‘rule of thumb’ build cost of $15k up to $25k depending on size and quality of materials.
• For kitchens allow a ‘rule of thumb’ build cost of $20k up to $50k, once again depending on size and quality of materials.
• Start thinking a budget point around $1,700 per square meter for single storey average home and $3000 for a two storey – remembering the adage “how long is a piece of string”. Remember all the points discussed that will affect this range.
• It is very easy to design the dream home, often less easy to afford it. Compromises both emotionally and financially may be required  in order to achieve a satisfactory result. Think outside the square.
• Contrary to popular belief, Builders do not make huge margins on constructions. Typically, it is between 10-20% gross profit. Profits can be eaten away very rapidly by unforeseen costs. A well detailed and specified plan should see no more than 5%-15% variation between quoted costs from differing Builders. Mistakes, lack of detail and material changes can affect this dramatically, food for thought.