Shared Ownership Staircasing Cost Calculator
Estimate Your Staircasing Costs
Calculate the true cost of buying additional shares in your shared ownership home, including all fees and hidden expenses.
Your Staircasing Analysis
Cost of Next Share
The purchase price of the next share
Total Fees
Valuation, legal, and mortgage arrangement fees
Total Cost
The true cost of this staircase step
What this means for you
Even if you can afford the mortgage for your current share, the fees and ongoing rent on the unowned portion could make staircasing financially challenging. Consider whether you're buying ownership or a long-term rental with extra costs.
Buying a home feels like the ultimate goal for many people-especially in places like Auckland, where rent keeps climbing and owning something of your own seems like the only way out. But if you’re considering a shared ownership scheme, where you buy a portion of a property and pay rent on the rest, you need to know the real downsides. It’s not all low deposits and staircasing dreams. There are hidden costs, strict rules, and long-term traps that aren’t talked about enough.
You don’t fully own your home
In shared ownership, you might think you’re a homeowner. But you’re not. Not really. You own a percentage-say, 25% or 50%-and the housing association owns the rest. That means you can’t make big changes without permission. Want to knock down a wall? Install solar panels? Paint the exterior? You need written approval. And if you want to sell, you can’t just list it on Trade Me. The housing association has the right to find a buyer first, and they often limit who can buy. That makes resale slower and harder. In 2024, a survey by Housing New Zealand found that 42% of shared ownership residents waited over six months to sell because of these restrictions. You’re stuck in a halfway house between renting and owning-and that’s not always a good thing.
Rent on the part you don’t own keeps going up
You pay a mortgage on the share you own. But you also pay rent on the part the housing association owns. And that rent doesn’t stay the same. Most agreements allow rent to increase annually, often tied to inflation or a fixed percentage like 0.5%-1.5%. In Auckland, where inflation has hovered around 3.5% since 2022, that rent can creep up fast. One homeowner in Manukau told me her rent jumped from $320 to $410 in three years-even though her mortgage stayed the same. That’s $90 a month you didn’t budget for. And unlike a mortgage, rent doesn’t build equity. You’re paying for the right to live in part of your home, but you get nothing back. Over 10 years, that could mean $10,000+ in pure expenses. That’s money you could’ve put into a KiwiSaver account or paid off debt.
Staircasing is expensive and complicated
The big promise of shared ownership is staircasing-buying more shares until you own 100%. Sounds great, right? But here’s the catch: every time you buy more, you pay for a full valuation. That’s $500-$800 each time. Then there’s legal fees, mortgage arrangement fees, and sometimes even a fee just to process the staircasing request. One family in Papakura staircased twice in five years. Each time, they paid over $1,200 in fees alone. By the time they owned 75%, they’d spent $3,000 just in paperwork. And if property values rise, the price of your next share jumps too. You thought you were locking in a low price, but now the housing association is pricing your next chunk based on today’s inflated market. If you’re not ready to pay $100,000 for the next 25% when your home’s worth $500,000, you’re stuck paying rent forever. Many people never make it to 100%-not because they can’t afford the mortgage, but because the costs keep climbing.
You’re locked into strict rules
Shared ownership comes with a rulebook thicker than a phone book. You can’t sublet, even if you get a job overseas. You can’t have pets without permission-and many associations ban dogs outright. Some won’t let you run a home business. Others require you to live in the property for a minimum of two years before even considering a sale. In 2023, a couple in Onehunga were fined $1,500 for renting out their spare room on Airbnb. They didn’t even know it was against the terms. These rules aren’t just inconvenient-they’re designed to protect the housing association’s investment, not yours. And if you break them? You could face eviction, even if you’ve paid your mortgage on time. You’re not a homeowner. You’re a tenant with a mortgage.
Resale value is capped
When you sell, you don’t get the full market value. You get the value of your share. But here’s the kicker: if the market goes up, you benefit. If it drops? You’re still on the hook for the rent on the part you don’t own. And if you try to sell when prices are down, you might owe more than your share is worth. In 2022, a homeowner in Mt Roskill had to top up $12,000 just to cover the gap between what her 60% share was worth and what she owed on her mortgage. That’s not a problem for full owners-they just sell and walk away. But in shared ownership, you’re financially tied to the housing association’s terms. There’s no clean exit.
Insurance and maintenance costs are yours alone
The housing association covers the building’s structure and common areas. But everything inside your unit? You pay. That includes buildings insurance (yes, you need your own), contents insurance, repairs to your kitchen, bathroom, or boiler. In Auckland’s older shared ownership developments, boilers break down every 5-7 years. Replacing one costs $3,000-$5,000. And guess what? The housing association won’t chip in. You’re responsible for everything from leaky taps to cracked tiles. That’s not just expensive-it’s unpredictable. You might think you’re getting a bargain on the price, but then you’re hit with a $4,000 repair bill out of nowhere. No savings plan can prepare you for that.
It’s harder to get a mortgage
Not all lenders offer shared ownership mortgages. Those that do often charge higher interest rates or require bigger deposits. In 2025, the average shared ownership mortgage rate in New Zealand was 0.8% higher than a standard home loan. That’s $200 extra a month on a $500,000 property. Plus, lenders look at your total housing costs-mortgage + rent-when deciding how much you can borrow. That means even if you earn enough, your rent payment might cap your borrowing power. You could be approved for a $400,000 home, but because you’re paying $450 rent on 40% of it, the bank says you can’t afford it. You end up stuck in a smaller place than you wanted, or worse, denied entirely.
You can’t move freely
Want to relocate for a job? Move closer to family? That’s not easy. If you’re in shared ownership, you can’t just sell and move. You have to find someone who qualifies for shared ownership-someone with a low enough income, a good credit score, and enough savings for a deposit. That pool is tiny. In Auckland, only about 12% of applicants qualify. That means your home could sit empty for months. You might end up paying two sets of bills-rent where you’re living and mortgage + rent on your old home. That’s not a lifestyle. That’s financial chaos.
Can you ever fully own your home in a shared ownership scheme?
Yes, you can buy more shares over time through a process called staircasing. Most schemes allow you to buy up to 100%, but it’s not guaranteed. Each step requires a valuation, legal fees, and sometimes higher mortgage payments. Many people never reach full ownership because the costs keep rising and they can’t afford the next step.
Are shared ownership homes cheaper to buy?
On paper, yes. You only need a deposit for your share, not the full property. But when you add up mortgage payments, rent on the rest, insurance, maintenance, and staircasing fees, the total monthly cost is often close to or higher than renting a similar property. You’re paying for the illusion of ownership without the freedom.
What happens if I fall behind on rent?
Even if you’re up to date on your mortgage, falling behind on rent can lead to eviction. Rent is a separate legal obligation, and housing associations can take action faster than banks. In 2023, over 80 cases of eviction in Auckland were linked to shared ownership rent arrears, not mortgage defaults.
Can I rent out my shared ownership home?
Almost never. Most shared ownership agreements prohibit subletting. Even temporary moves-for work, study, or travel-require written permission. Violating this rule can result in fines, legal action, or loss of your home.
Is shared ownership better than renting?
Only if you plan to stay put for 10+ years and can afford the hidden costs. If you need flexibility, want to build equity quickly, or can’t predict future expenses, renting might be cheaper and less stressful. Shared ownership trades freedom for a partial stake-and that trade isn’t worth it for everyone.
Final thought: Ownership isn’t always the answer
Home ownership is sold as the dream. But in shared ownership, that dream comes with strings. You pay more over time, you have less control, and you’re stuck with rules designed to protect someone else’s investment-not yours. If you’re considering it, ask yourself: Am I buying a home, or am I buying a long-term rental with extra fees and no escape? The answer might surprise you.