Co-ownership — purchasing a property with one or more people who aren’t your partner — is an increasingly common route to homeownership in New Zealand. Buying with a sibling, friend, or via a shared equity scheme can dramatically improve affordability. But co-ownership introduces legal and financial complexities that a standard joint mortgage between partners does not.
Co-ownership with 2–3 people can significantly improve borrowing capacity and deposit access. Two people each earning $65,000 can borrow up to $780,000 jointly. The key legal protection is a co-ownership agreement (drafted by a solicitor) that covers exit rights, cost-sharing, and dispute resolution before you purchase.
Types of Co-Ownership in NZ
1. Tenants in Common (most common for co-buying)
Each owner holds a defined share of the property (e.g., 50/50 or 60/40), and each share can be sold, gifted, or passed through an estate independently.
- Best for: Co-buying with friends, siblings, or unequal contribution situations
- Key feature: Shares can be unequal, reflecting different deposit or income contributions
- On death: Shares pass under each owner’s will (not automatically to the other owner)
2. Joint Tenancy
All owners hold the property equally as a unified whole — no defined individual shares. On the death of one owner, their interest passes automatically to the surviving owner(s) (right of survivorship).
- Best for: Married couples (but tenants in common is usually better for co-buying non-partners)
- Key feature: No individual shares — all or nothing
Affordability Benefits of Co-Buying
Two buyers with combined income unlock dramatically more purchasing power under DTI 6×:
| Scenario | Combined income | DTI max mortgage | 20% deposit target price |
|---|---|---|---|
| Two × $50,000 | $100,000 | $600,000 | $750,000 |
| Two × $65,000 | $130,000 | $780,000 | $975,000 |
| Two × $80,000 | $160,000 | $960,000 | $1,200,000 |
| Three × $60,000 | $180,000 | $1,080,000 | $1,350,000 |
Combined KiwiSaver withdrawals can also be pooled — two first home buyers can each withdraw their KiwiSaver balance for use as a joint deposit.
The Co-Ownership Agreement: Essential Legal Protection
A co-ownership agreement (also called a Property Sharing Agreement) is a private contract between the co-owners that sits alongside the mortgage. It should cover:
Key provisions
- Ownership shares: Who owns what percentage
- Contribution split: How mortgage repayments, rates, insurance, and maintenance are split
- Decision making: Who decides on major decisions (renovations, selling, taking in boarders)?
- Exit rights: Can one party sell their share? What process applies? Do the other owners get first right of refusal?
- Forced sale provisions: What triggers a forced sale? How is the price agreed?
- Death and incapacity: What happens to a deceased owner’s share?
- Default: What happens if one co-owner cannot pay their share of the mortgage?
Cost: A solicitor-drafted co-ownership agreement typically costs $1,500–$3,000 but is essential protection. Disputes between co-owners without a formal agreement can become extremely costly.
The Mortgage Structure for Co-Buyers
All co-buyers must be on the mortgage application — each is assessed by the bank (income, credit, existing debts). All are jointly and severally liable for the full mortgage debt.
Key point: If one co-owner stops paying, the bank can pursue the others for the full balance. This is the main risk of co-ownership — you are guaranteeing your co-owner’s share as well as your own.
Lenders do not typically structure separate mortgage accounts for each co-owner’s share — the mortgage is a single loan, jointly held.
Shared Equity Schemes in NZ
Beyond co-buying with known individuals, some shared equity options exist:
Kāinga Ora schemes
Kāinga Ora (formerly Housing NZ) operates various shared ownership programmes in selected areas and for eligible buyers. Check the Kāinga Ora website for current availability — these schemes change over time.
Iwi housing schemes
Several iwi (tribal authorities) operate housing assistance schemes for eligible members, sometimes including shared equity arrangements.
Private co-ownership platforms
Emerging private platforms allow buyers to purchase a partial share (e.g., 75%) in a property and pay rent on the remainder, with the ability to buy additional shares (staircasing) over time. These are relatively new in the NZ market and carry their own contractual risks — review carefully with a solicitor before entering.
Risks of Co-Ownership
| Risk | Mitigation |
|---|---|
| Co-owner cannot pay their share | Co-ownership agreement with clear default provisions; shared emergency fund |
| Co-owner wants to sell at a bad time | Pre-agreed sale process in co-ownership agreement |
| Relationship breakdown between co-owners | Professional co-ownership agreement; dispute resolution clause |
| Property cannot be sold without all consent | Tenants in common structure allows individual share sale |
| Different views on maintenance/renovation | Decision-making rules in co-ownership agreement |
| One co-owner dies | Agreement addresses disposition of shares |
Exiting a Co-Ownership Arrangement
Common exit scenarios and mechanisms:
- One owner buys out the other: The remaining owner refinances to include the departing owner’s share in their own name. Requires solo qualification under DTI and serviceability at the time
- Sell the whole property: Both parties agree to sell and split proceeds per ownership shares
- One owner sells their share to a third party: Tenants in common structure allows this; your co-ownership agreement should specify a right of first refusal for the remaining owner
- Staircase: In shared equity schemes, one party buys additional shares over time
Frequently Asked Questions
Can I co-buy a house with a friend in NZ?
Yes — co-buying with a friend (or sibling, or any non-partner) is legal in NZ and can significantly improve affordability. All co-buyers apply for the mortgage together and are jointly and severally liable. A co-ownership agreement is essential.
What is the difference between a joint mortgage and co-ownership in NZ?
A joint mortgage simply means multiple people are on the mortgage (joint and several liability). Co-ownership refers to the legal structure of how the property is held — either joint tenancy (equal, unified) or tenants in common (defined individual shares). Most non-partner co-buyers should use tenants in common.
How do co-buyers split mortgage repayments in NZ?
This is set out in your co-ownership agreement. Splits can be proportional to ownership share, proportional to income, or any other agreed arrangement. Banks require all co-owners to remain current on the mortgage regardless of private arrangements.
What happens if my co-owner can’t pay their share of the mortgage?
The bank will expect someone to cover the full repayment — your co-ownership agreement should include provisions for this scenario (emergency fund, notification period, buyout right). You remain jointly and severally liable for the full debt.
Can first home buyers each use KiwiSaver in a co-ownership?
Yes — each first home buyer on the purchase can independently withdraw their KiwiSaver balance (subject to the 3-year minimum membership rule) and pool the funds toward the deposit.