Cohaus

Awards

• NZIA Auckland Branch Award - medium density housing 2023
• NZILA award - Residential and Gardens category award winner 2024
• SEANZ - Best Environmental Impact Award 2021

The understated street presence of Cohaus conceals a rich internal complexity and a tight-knit community. The result is a new typology for medium-density housing in Aotearoa New Zealand, with shared facilities providing a range of community benefits. Sustainability defined this project from the outset and now provides residents with significant savings on energy and water costs. Various design strategies, construction methodologies and material solutions are combined to deliver a cost-effective, yet entirely pleasing design outcome. As New Zealand continues to navigate complexities and challenges across the housing continuum, Cohaus establishes a new bar to which future multi-unit projects should aspire.

— NZIA Auckland Branch Awards 2023 - jury citation

Cohaus is successful for its collaborative design approach; creating a residential environment that is beautiful, sustainable, and creates exceptional added value to its community of residents.

The design shows a strong sense of place by use of edible gardens, local rock materials, climbing plants on the vertical face of buildings, and consistent theme throughout of shared communal living. This enhances its sense of place as a residential living community alongside nature. It is both well executed and innovative for its environmental sustainability, co-habitation, and design clarity…concrete and hard surfaces are kept to a minimum…the street interface successfully incorporates the wider public into the design through shared seating areas and materials within the footpath corridor that visually link with the architecture and overall character, giving a sense of extending manaakitanga to those passing along the street frontage.

— NZILA awards 2024 - jury citation

The fundamentals

Cohaus is a thriving housing community of 20 beautiful dwellings - 4, 3, 2, 1 bedroom and a studio - spread across a 3 storey apartment building, a 2 storey terrace and a villa, all sharing a huge exuberant garden on a 2407m2 site in Grey Lynn, Tāmaki Makaurau Auckland. Beside the garden Cohaus has enviable shared facilities: a common space, a laundry, a bike stable for 60 bicycles, six share cars and a guest flat. Completed in 2021, Cohaus breaks new ground as Aotearoa New Zealand’s first urban cohousing development and is home to a big-hearted community of 53 people aged 0 to 81.

Sited on the edge of the inner city and straddling a local interface between historic detached villas and modern high-density land use, Cohaus builds a lot of homes stacked beside and on top of each other. The development achieves a residential density of 220 people per hectare compared to the Auckland average of 24, while keeping hold of the best bits of kiwi suburbia - one big back yard without fences for kids to range, windfall on the lawn from fruit trees, shared childminding, your own outdoor deck, neighbours lending and borrowing, communal celebrations and unlocked front doors.

Cohousing - what’s that?

When we say ‘cohousing’, we mean a resident-led, not-for-profit model for collectively developing and operating housing that is found across the world. In cohousing, residents live in private apartments, jointly own common spaces, share amenities, and work together to run the housing complex. Though drawing on experiences in European countries, cohousing echoes the traditions of indigenous Māori collective housing development in papakāinga, pā, and kāinga.

Cohaus’ journey began in 2015 with 2 lead families deciding to pool their money and time to tackle a multi-unit cohousing development in Tāmaki Makaurau Auckland. They quickly attracted a core group of 6 like-minded households and over time this group grew to the 20 households that ultimately signed a development agreement and became a housing community. Housing development is normally driven by a professional developer selling ‘off-plan’. Market housing is designed to maximise short-term profit and plays it safe by isolating separate units from each other as much as possible, a self-reinforcing social atomization that the future Cohaus residents rejected emphatically. With Cohaus a fantastic site was bought and the design developed around the long-term needs and preferences of the community. The design process was participatory with continuous communication with residents who contributed feedback, expertise and work. Any projected profit was ploughed back into the project. All the funding for Cohaus up to well into the construction phase came from the residents and their extended families, sharing financial risk and creating powerful bonds of trust.

Architect / developer

Studio Nord are passionate about creating the lovely, sustainable urban housing with active communities they enjoyed for many years living in Copenhagen and London. This meant going all in on Cohaus as one of founding families, joint project conceptor and director, architect, funder and construction project manager, and finally residents involved in community governance and facilities management. Wearing the developer’s hat for a change gave us a completely new level of insight into the business of building housing - the risks, the pressures, but also the opportunities. To see the outcome of years of collaborative work in a housing community that will last generations, that people in the street stop to admire, makes us incredibly proud.

Simple, beautiful homes

Cohaus is a ‘compact city’ urban development that massively increases density without sacrificing residential quality. Sited within a heritage zone the design creates a respectful presence in the neighbourhood by the careful modulation of building volume and well-proportioned facades composed of traditional materials - brick and timber weatherboards. All dwellings are at least dual aspect with shallow floor plans 8 to 9m deep providing equal access to sun, air, private external space and community amenities. Apartments are accessed from street side double-loaded stairwells and run out onto continuous sheltered timber ‘living decks’ that exemplify the community spirit of Cohaus with kids running end-to-end between different homes. The rear 2 storey terraces have separate ground level front entrances and garden access through sheltered patios. The existing 19th century villa, first house built on the street, was moved from the centre to the corner of the site and restored as a period home. Unit living spaces increase in size in proportion to the number of bedrooms. Instead of multiple ensuites most units have only one bathroom and room for a washing machine, although households much prefer the common laundry. All internal spaces are planned alike to reduce cost, have natural light and straightforward, good quality finishes. To let residents individualise their units Studio Nord developed a cost-neutral matrix of choices for interior design like floor finishes, cabinetry, appliance specification and even the colour of their front door. No two homes are alike.

Building a community

In community-focussed housing like Cohaus the people are every bit as important as the architecture. From the start the future resident group met regularly, ate together and celebrated project milestones. There are many parallels with the Maori concept of whanaungatanga: the cultivation of kinship relationships and a sense of home through shared experience and working together, and an intention to build the physical conditions for the strengthening and weaving together of a community over time. Beautiful shared spaces like the garden house are designed for daily use and complement private living areas. The spatial design encourages residents to bump into each other and catch up. Shared amenities - cars, common laundry, guest flat (which reduces households’ need for a spare room), garden house (for celebrations, meeting, play), landscape, food production, bike store, carpark, garden shed, tools, toys, sandpit, playhouse, bbq, pizza oven, outdoor clotheslines, compost bins - are used by everyone and require tolerance and cooperation. Residents use their own time and skills for management and maintenance. Active residents propose, discuss and make small improvements to common spaces so the shared environment is constantly being crafted by the people who live there. Working together in this way produces a proliferation of housing and welfare benefits. Young families can co-parent or share childcare. Residents make their units available to others while they are away and give pastoral care to neighbours hit with sudden illness. Others pass on possessions no longer needed and borrow from each other. Households combine their knowledge to address shared issues, reducing individual stress and loneliness.

Urban oasis

Everyone walking into Cohaus’ courtyard for the first time is blown away by the garden, bursting with fruit trees, natives, banana palms, ferns, herbs, veges and birds. Drawing on European courtyard housing block models and the traditional kiwi back yard, Studio Nord wrapped living units around the largest possible green space in the middle, while planting out the mandatory perimeter yards and setbacks. Following the maxim that “every home needs a garden” all living rooms relate directly to the courtyard through their private outdoor living deck or patio. Soft landscaping and temporary planting screens rather than fences create boundaries between private/shared/communal zones and areas of defensible space. It’s an ideal play environment for young children and every afternoon the community’s kids race each other around the buildings. Residents call the courtyard their taonga, or treasure, and everyone helps out in the garden. Low basalt “paddock” rock retaining walls, open play spaces, movement paths and planting beds developed in a co-design process between Studio Nord, residents and different landscape architects over several years, and continue to evolve.

Breaking the car habit

Hilly, spread thin and riddled with more public transport ‘black holes’ than the local scoria rock, Auckland is dependent on cars. Cohaus tackles this hard truth with multiple innovations to reduce the impact of cars. We fought Auckland Council to be allowed to provide only 10 carparks, half the minimum requirement. To purposefully separate cars from people’s homes carparks, with a bare minimum of hard paving (kept permeable), are concentrated on a fenced-off road corner. Only two parks are allocated to units, two to visitors and three carstackers accommodate the community’s six hybrid and electric share cars that all residents book and use at low cost. A central secure bike store with custom racking and ample charging points enables most residents (many with e- or e-cargo bikes) to do most of their travel by bike, including school runs and getting the groceries. Cohaus’ amazing location on an urban ridgeline with local schools, shops and bus stops close by helps too.

Power to the people

We set out to do things differently with Cohaus’ utilities, the lifeblood of a home and a big part of the cost of living. Studio Nord, Re/volve and the residents developed a community energy system based on a customer network supplying electricity, hot & cold water and internet to all units. The community buys wholesale power, water and broadband from utility companies through a single account and charges households according to their usage.The system captures usage data in an online dashboard for residents and smooths load peaks by automatically shifting power between units, car charging and the hot water system. Access to the billing software infrastructure is used to charge for the shared washing machines and dryers, use of the shared low-emission cars and a community refill shop of household products like milk.

A rooftop solar system of 124 photovoltaic panels contributes 38.44kW and excess solar electricity generation is soaked up by the central hot water system. A pair of electric heat pumps produce 2860L of hot water in storage tanks that is distributed to units by circulating ring mains. The central system was twice as expensive as conventional individual hot water cylinders but frees up space in people’s homes and has paid for itself in energy savings in less than 3 years.

All this combines to make Cohaus incredibly energy-efficient. The complex uses 33 kWh/y.m2, well below the New Zealand Governments 2035 Building for Climate Change (BfCC) target of 45 kWh/y.m2, and has just downgraded the network power connection from a pre-construction design requirement of 250A to 100A of actual used capacity. Resident participation is a huge factor in the success of the community energy system and the benefit is clear - the average Cohaus household spends just $184 per month on all utilities combined.