A new home quote and the final cost of getting into a finished house are two different numbers. The gap between them is site costs and exclusions.
The two halves of a new build budget
The house
The building itself: slab, frame, roof, lock up, services, linings, wet areas, joinery, finishes.
The site and everything around it
Demolition of anything existing, earthworks, retaining, drainage, service connections, driveway, paths, fencing, landscaping, and any authority requirements. On a difficult block this half can be a very large number.
What drives the cost of the house
- Size and shape. Simple rectangular forms with fewer corners are cheaper per square metre than complex articulated plans.
- Number of storeys. Two storey homes use land more efficiently and add stairs, structure and access requirements.
- Roof form. Complex roofs cost money in structure, flashing and labour.
- Glazing. Large format and stacker doors are one of the largest single swing items in a build.
- Wet areas. Bathroom count is a significant driver, since each one concentrates trades and materials.
- Level of finish. Joinery, stone, tiling, flooring, tapware and appliances create very wide variation between two identical floor plans.
- Structural requirements. Wind classification, bushfire construction requirements and engineering all set minimum standards that cost money.
What drives site costs
| Site factor | Effect |
|---|---|
| Slope | Retaining, cut and fill, stepped footings, access difficulty |
| Rock | Slower, more expensive excavation |
| Soil classification | Footing and slab design, reactive soils cost more |
| Existing structures | Demolition, disconnection and disposal |
| Access | Craneage, material handling and machine size |
| Drainage and stormwater | On site detention or absorption systems where required |
| Service connections | Distance to water, sewer, power and gas, and any authority works |
| Trees | Protection requirements or removal approvals |
| Bushfire or flood | Prescribed construction requirements |
Two identical houses on two different blocks in Sydney can differ dramatically for these reasons alone.
Commonly excluded from headline build prices
- Site costs and earthworks beyond a nominal allowance
- Demolition
- Driveways, paths and external concreting
- Decks, pergolas and outdoor structures
- Fencing, letterbox, clothes line
- Landscaping and turf
- Window coverings, insect screens
- Air conditioning
- Upgraded appliances, tapware and floor coverings
- Authority fees, contributions and connection charges
When you compare build quotes, compare the exclusion lists first. They explain most of the difference.
How to keep a new build under control
- Get a soil test and a survey before you finalise the design. Both feed directly into cost.
- Design a simple, efficient form and spend the savings on the things you touch daily.
- Fix the specification before signing. A detailed specification is your protection against creeping allowances.
- Lock in your selections early and understand which items are long lead.
- Keep a contingency for site conditions, particularly on sloping or rocky blocks.
- Understand the progress payment schedule and align it with your finance.
Compare against the alternative
If you already own a house on the block, it is worth pricing a substantial renovation or extension against a knock down rebuild before committing. Renovate or rebuild sets out how to make that call, and how much a home extension costs in Sydney covers the extension path.
What happens next
What to expect during the new home construction process walks through the stages, and questions to ask a builder before signing a building contract covers the paperwork.
Site costs vary more than the house
Two identical house designs on two different blocks can differ substantially before a single wall goes up. The variables:
| Factor | Effect on cost |
|---|---|
| Slope | Retaining, drop edge beams, more excavation and fill |
| Rock | Excavation and footing costs rise quickly |
| Soil classification | Determines slab and footing design |
| Access | Restricted access means smaller machines and more labour |
| Trees | Protection measures, arborist involvement, sometimes footing changes |
| Services | Distance to connections, upgrades, easements |
| Stormwater | On site detention or absorption systems where required |
Site costs are where fixed price advertising most often unravels, which is why a soil test and survey before pricing are worth doing rather than deferring.
What is often excluded
Read any new home quote for these specifically: driveway and paths, landscaping and turf, fencing, letterbox and clothesline, flyscreens, window coverings, air conditioning, floor coverings to all rooms, external lighting, and the cost of connecting each service. A quote that excludes most of them is not comparable to one that includes them.
Making comparisons fair
Ask each builder to price the same documented scope, and ask for their inclusions list in writing. Then build a simple comparison sheet with a row for every item, including exclusions, so you are comparing the same house. The cheapest headline figure frequently becomes the most expensive project once the missing rows are added.
ORT Constructions builds new homes and major residential projects across Sydney, with structural carpentry and concreting capability in house. See all of our building services.
Frequently asked questions
- Why do new home quotes vary so much?
- Mostly because of exclusions and site cost allowances. Two quotes for the same plan can differ substantially once demolition, earthworks, driveways, landscaping and finishes are compared properly.
- What are site costs on a new build?
- Everything the block demands rather than the house: earthworks, retaining, rock excavation, drainage, service connections, demolition and access requirements.
- Is a two storey home more expensive than single storey?
- Per square metre it can be similar or better, because you build one roof and one slab area for two floors. It adds stairs, structure and access costs, and it uses a smaller footprint on the block.
