How much does it cost to demolish a house?
Demolition is generally is the initial works to be undertaken on any project. It should cost you within the range of $8,000 - $32,000 to have this work carried out in New Zealand. In a perfect world the main costs drivers are the time spent carrying out the works and the amount of un-salvageable material that gets sent to the dump.
Estimates based on the size of the home:
$8,000 / 40 m2 ($150 -$200) - Standalone studio, limited internal stud walls
$20,000 / 120 m2 per level ($120 - $170) - Two Storey Home with good access.
$32,000 / 200 m2 per level ($115 - $160) - Mutlistorey Home over different levels.
If it were this simple, all projects would run on budget, there are other costs which may affect the final bill and it is worth getting your head around before penciling in your works.
Asbestos - $600 - $15,000 or Friable Asbestos $3,000 - $30,000+
The most common additional cost, typically only buildings built before 2000, The price largely depends on the extent of the asbestos and the type, also known as friable / non-friable or bonded / fibrous. A good contractor will be able to provide a price for visually identified asbestos, but as the material can be hidden anywhere, without a intrusive Asbestos Survey even the best Estimators can get it wrong. It may be worthwhile contacting an Asbestos Surveyor before speaking to demolition contractors so you have idea of the amount of asbestos needing removal.
It is worth noting where you have over 10 m2 of non-friable or any quantity of friable material this must be removed by a licensed asbestos removal contractor in New Zealand.
Access - $2,000 - $10,000
A large benefit to demolition contractors is being able to bring in a suitable machine for the job both in reach and to select the right tool.
If the driveway access is limited this may lead contractors to undertaking the works utilising smaller machines and various hand techniques to demolish the structure increasing the project time and cost.
Proximity of Neighbours - $1,500 - $6,000
It may be why you've decided to knock down your house, but the closeness of the neighbouring properties to yours will affect the method of the contractor and subsequent cost.
The general industry guideline is for there to be a gap of half the height of the building to the next structure. It relates to the parabolic trajectory of the material, but that is an issue us to manage.
Where homes are too close and the fall of materials cannot be managed safely. There is an option to put up scaffolding to create a temporary wall between your properties and give the demolition machine driver screen to work behind. Scaffolding a structure under going demolition can be difficult and it may cost more to ensure it is done correctly by having the designs agreed with an engineer.
Salvage vs. Furniture ($2,000 - $4,000 as credit)
A large benefit for us doing the demolition is being able to salvage & recycle old materials out of the structure. The cost can be driven higher by leaving your unwanted furniture & loose fittings, or a credit can be given for resell-able items.
Credits generally relate to recycling of steel and precious metals, & these will fetch the best outcome for you the home owner as they are easy to on sell.
With the current surge in demolition projects, the salvage market has surplus supply and thus the resale market is only interested in the highest quality materials. This may lead to a reduction in salvage on each project as the lower quality product may be harder to resell.
Demolition doesn't always have to be a costing exercise, here are a few ways you can ask us to work with you to provide a cheaper quote.
Follow on Earthworks - 5% - 10% of full quote
Improve the efficiency and timing of your project by employing the Demolition Contractor to rebuild your site & do the earthworks. We are all expects in aggregates, metal & stone and typically have excavated your site to grub out the foundations. It is not only more cost effective to have us continue into the earthworks but can often reduce weathering on open excavations and improve the safety of the site when excavations are filled in as they are generated.
Control the Asbestos Removal
A competent demolition contractor as an industry are already trained in asbestos awareness, supervision and often removal. It can be beneficial to your house removal if the demolition contractor either controls or carries out the asbestos removal.
The contractor can offer savings in reduced labour or programme overheads by reducing the time they are on site by managing safely the asbestos removal in line with their own internal strip out. This generally has the additional benefit of unidentified asbestos material being uncovered early enough that the asbestos can be removed without extra taking extra time on site.
Produce Aggregate / Stone / Metal
An untapped resource in house removal is recycling the hardcore of concrete, brick rubble and turning that into stone / aggregate for the earthworks or remediation. Has the potential to drastically reduce the cost of bringing in metal for your subbase, often councils are more lenient with recycled material and it gives the project a positive image in the ecology and recycling departments.
Though not as popular in New Zealand, with the number of accessible quarries, there will be an increase in site crushing in the years to come as recycling becomes more prevalent & beneficial to customers.