Case Study: Piritahi House Removal Programme
The Accord Piritahi case study focuses on reducing construction waste by saving and relocating homes.
Construction is the biggest contributor to landfill waste in New Zealand. Auckland alone produces at least 568,935 tonnes of construction and demolition waste a year. Piritahi's House Removal Programme is focused on reducing these statistics by removing homes in the most environmentally responsible and cost-effective way possible, by saving and relocating homes.
Piritahi is an alliance responsible for the delivery of the Auckland Civils Alliance Programme (ACAP), involving large scale infrastructure works and land remediation for new housing developments currently underway in Tāmaki Makaurau. Leading this work is Kāinga Ora: Homes and Communities, the partner and sole client of Piritahi. Throughout the life of the ACAP, there are approximately 7,000 state houses that require removal from large scale project areas. On top of this, Kāinga Ora is upgrading and removing thousands more homes as part of its national public housing programme.
Programme goal: To remove the ACAP houses in the most environmentally responsible and cost-effective way, by saving and relocating as many homes as possible.
- Since Piritahi commenced works in late 2018 it has removed 503 houses, with 23% saved for refurbishment and relocation – three times over the proposed target
- Since July 2020, Piritahi has increased the volume of house relocations to 29% – the target was 7%
- At the Aorere development, 79% of the removed houses were relocated (34 out of 43 houses), with only six deconstructed and three demolished – with a high intensity of salvage
- 92% of Piritahi's construction waste has been diverted from landfill since July 2020 – the target was 80%
- From July to December 2020, Piritahi diverted more than 5,000 tonnes of construction waste from landfill – recycling core materials and contributing to the circular economy.
Applies to: Construction clients, consultants, developers and contractors who are considering or undertaking the demolition of a house or houses.
- Increase productivity
- Restore confidence, pride and reputation
- Healthy and safe Kiwis
- Access to quality affordable housing
- Stable, healthy and more productive construction sector
- Strong, reliable and enduring infrastructure
- Better whole-of-life value for taxpayers
- Sustainable buildings and infrastructure created with minimal environmental impact.
- Act with collective responsibility
- Planning for the long-term
- Acting as a custodian for the sector’s future
- Sharing knowledge and lessons learnt
- Prioritising environmental sustainability.
Programme stage: Housing removals will continue throughout the Auckland Civils Alliance Programme (ACAP).
Beacon monitoring process: The Accord Beacons team will monitor Piritahi’s progress throughout the Auckland Civils Alliance Programme (ACAP).
Piritahi case study video
House Removal Programme
Kāinga Ora is leading the largest urban regeneration programme ever undertaken in New Zealand, transforming suburbs and communities across the country through a series of projects of various sizes.
In Tāmaki Makaurau, the regeneration will deliver nearly 30,000 warm, healthy homes for many Aucklanders. It will help provide more state housing, more homes for first home buyers and a greater supply of homes on the market to accommodate the city's growing population.
It will also improve and increase amenity, public space, and infrastructure for Auckland. These large-scale works fall under the Auckland Civils Alliance Programme (ACAP) and are being implemented by the Piritahi alliance.
Much of the land Kāinga Ora is developing is underutilised, which is why the goal is to make better use of the land by creating more homes. As part of this goal, Piritahi is responsible for removing thousands of state homes to prepare the groundwork for future housing. More than 7,000 homes will have to be removed during the programme.
Careful consideration is given to sustainability in the programme, taking Kāinga Ora's policies and environmental targets into account. As Piritahi's sole client, Kāinga Ora have championed a more sustainable approach – driven by construction waste being the biggest contributor of landfill waste in New Zealand. The environmental costs are exacerbated financially by invisible costs such as offcuts, damaged goods, poor-onsite storage, site waste management, shrinkage, transport costs, and administration and compliance costs – making the cost ten times the price of disposal.
The Piritahi Early Works Team was formed specifically to focus on sustainable and cost-efficient delivery of the house removal programme. The goal is to fundamentally shift the disposal of state homes from demolition, to a more environmentally-friendly approach of relocation, deconstruction and recycling. Piritahi has committed to minimising material that ends up in landfill, optimising sustainable opportunities and leading innovation throughout the sector.
While this sustainable approach is largely focused on better environmental outcomes, social outcomes are also a key component. Kāinga Ora has been providing existing state homes for relocation to iwi groups for several years. As the relocation programme gains momentum, Piritahi and Kāinga Ora are exploring opportunities to extend the opportunity to more iwi, urban Māori groups, NGOs and community groups.
As part of the commitment Kāinga Ora has made to greater sustainability in house removals, it's in the process of setting up a new site clearance panel containing three sub categories; house relocation, deconstruction and demolition contractor panels.
In collaboration with Kāinga Ora, Piritahi supplied 19 relocatable houses to a transitional housing programme. It has also formed a charitable partnership with Ara, a charitable trust that connects South Auckland communities with businesses working near Auckland Airport. The houses are refurbished by secondary school students in gateway programmes or tertiary apprenticeships. Ara’s social sustainability model uses the houses as a training ground for its students, and recovers the costs of refurbishing the houses by selling them to relocation companies.
"Piritahi is an excellent example of the fundamental principles of the Construction Sector Accord. It is collaborative, we're innovating, risk is really well managed and allocated to those people best equipped to deal with it and there's a lot of upskilling and investment in plant and equipment going on." - - Mat Tucker, Alliance General Manager, Piritahi.
Houses earmarked for removal are evaluated in three ways:
- Relocation – the house is saved and refurbished into a new home. Kāinga Ora's national state housing programme has a target of relocating 7% of houses from development areas. This currently equates to approximately 70 homes a year.
- Deconstruction – at least 80% of the materials in the house are salvaged for reuse and recycling within Auckland public housing development areas and large scale projects. Deconstruction targets for the regions will follow.
- Demolition – materials are salvaged for reuse and recycling, but at less density.
A house removal specialist will determine whether a house is fit to be relocated, based on the following variables:
- Whether the house has been built on piles – concrete slabs prove more difficult and costly
- Cladding – weatherboard is preferable over other cladding, such as brick
- Location of the site – a house at the bottom of a steep section is difficult and sometimes impossible to relocate
- Condition of the house – it must be in reasonable condition and able to be refurbished
- Height of the house – single storey units are preferable, or the pitch of the roof and the height of the building must be under 5.4 metres – to ensure the structure can travel safely on roads and not strike overhead obstacles.
Once a house has been earmarked for relocation it must be protected, after vacant it's vulnerable to theft and exposure from the natural elements. Then the main utility connections (e.g. power, water, gas, and telecommunications) to the house are disconnected and any asbestos is safely removed.
The houses are then handed over to housing relocation companies who refurbish and relocate them within the North Island. Once relocated, private drainage and new utility services are connected.
If a house is unfit for relocation the next option is deconstruction, with the aim of salvaging 80% of the materials from the house (a target based on Kāinga Ora and Auckland Council benchmarks).
Salvaged materials can include ovens, laundry sinks, shelves, doors, timber frames, trusses, roof tiles, window frames, wooden flooring, flooring joists and timber. Salvaged materials are recycled locally – timber is chipped or used for firewood, native timber is repurposed, steel is melted and concrete is crushed up and reused.
Demolition is the last option, after all other options have been exhausted. Demolition companies sort the demolition waste, salvaging what they can for reuse and recycling, but at a lower density rate than during deconstruction. Salvaged materials can include ovens, sinks, hot water cylinders, copper pipes, guttering and downpipes.
Outcomes and benefits
Piritahi is currently relocating 29% of the state houses it removes, saving their waste from landfill and putting homes back into the New Zealand housing stock.
In addition to this, 92% of uncontaminated construction waste from the remaining deconstructed or demolished houses is being saved from landfill.
On average, this approach saves around 1,000 tonnes of construction waste per month and these numbers are likely to increase over time, as the Piritahi Early Works team aims to refine their processes and practices. Across the lifespan of the ACAP, this approach will have a significant and profound impact on the environment.
Piritahi has been donating houses to Ara, a charitable trust that acquires the houses and uses them to train local young apprentices and secondary school students in gateway projects.
Additionally, 19 houses from the Aorere development were relocated for transitional housing, in collaboration with Kāinga Ora, demonstrating the potential for Piritahi’s housing relocation work to deliver more tangible benefits for the community.
"The key to this success has been not only thinking about the environmental outcomes we aim to achieve, but also social outcomes and figuring out end solutions that will also nurture and support the community." - Hugh McLaughlin, Early Works Operations Manager, Piritahi.
Piritahi has invested in its housing removal team to maximise the opportunities this programme of works presents for the alliance and Kāinga Ora. The Early Works Team is a group of six specialists, including an operations manager, site supervisor, asbestos specialist and site engineers. Having a core group of specialists in place has created an opportunity to implement ongoing processes that drive efficiency and performance.
These processes include:
- Creation of a GIS Dashboard to monitor and record the status of houses across all precincts, which has significantly improved visibility of houses, programming, quality control and quality assurance deliverables.
- A service disconnection process – through direct engagement with service providers, service disconnections are coordinated with Vector and Chorus via a live spreadsheet, reducing disconnection times from eight weeks to three weeks.
- Sub-contractors following of the Early Works process has improved health and safety significantly.
Social and economic learnings
Donating relocatable housing is not as straightforward as simply handing over a house for relocation. Any charitable benefactor of relocatable homes must ensure the housing is successfully relocated and refurbished into quality housing.
Social initiatives have been successful so far and, alongside Kāinga Ora, Piritahi will continue to seek out opportunities to achieve similar outcomes.
Since the commencement of the financial year in July 2020, house relocations and diversion from landfill rates have significantly increased. During this time, Piritahi invested in its house removal team by increasing resources and putting relevant targets and measures in place.