[DRAFT] – To be done by Feb 2023 otherwise please leave a comment if you want more details. TBC – roof hips and valleys, brick vs cladding/Hebel over empty space.
Energy and Thermal Ratings
If you design a passive home you may require less double glazing or other alterations to the design to comply with BASIX and NatHERS. An architect or energy assessor can help you with this aspect of the home. Builders can pass on large extra costs to comply which might not have been required if the design incorporated these principles from the start.
todo: Add BASIX examples like changing from solar to a washing line to pass BASIX energy component
How the First Floor sits above the Ground Floor
Take a look at where your first floor sits above ground floor. If theres no external wall underneath you will need something to support it.
todo: steel span across 6m
How to improve this
Ensure there is framing or external wall for part of the room to run along.
todo: add photos
Ins and Outs
todo: show photos
On a level block a square/rectangle would be the most efficient design. Where walls go in and out this leads to more walls being required which means more framing, gyprock, painting, etc.
Take a look at the Windows page for more detail on the different types of windows and their costs.
Things that can blow the budget (todo: add photos):
Windows/Doors exceeding 2.4m
When you need a larger size than this you need to upgrade to commercial windows. These can add anywhere from a few hundred to a few thousand extra.
Large Single Pane Windows
Large single pane windows – Where the windows exceed 80kg the window company can charge an onsite glazing cost which is around $500 per window. You may also require a crane to move the window if its to the back of the house.
You can break up the windows into sections however if you use silicone to join them together instead of a frame this can cost extra too
Windows to the eaves
If you have lower first floor ceilings, say around 2.4-2.5m, you can save a little bit by having each windows lintel/head be just below the eves. You would save on having the cost of a lintel to support the bricks above it. Around $50-100 per window can be saved.
Standard Window Sizes
If the windows are standard sizes, they would match the brick courses and this means a storm mould isn’t required. It’s a small saving and worth checking the cost difference for installation.
Some window manufacturers have standard sizes which are cheaper than custom but not all follow this rule eg. Wideline do have cheaper residential standard sizing than custom but Stegbar don’t.
Minimise ridges and valleys. The cost difference should be discussed with the build. (Todo: show example with master bedroom roof line)
If retaining walls are required that are over 600mm in some areas you will need them to be designed by an engineer and be certified. By raising or lowering the house or having splits you may be able to reduce this as fewer cuts or fills might be required.