Shared Ownership Cost Calculator
Understand Your True Costs
This calculator shows how shared ownership costs compare to private renting over time, including hidden expenses like valuations and rent increases.
Shared ownership sounds like a smart way into homeownership-especially if you’re struggling to save for a full deposit. You buy a share, pay rent on the rest, and slowly climb toward full ownership. But here’s the truth most brochures don’t tell you: owning shares in a shared ownership home comes with real, everyday headaches that can add up faster than you expect.
You’re stuck with rules you didn’t sign up for
When you buy a share in a shared ownership home, you’re not just buying property-you’re signing a lease with a housing association. That means you’re bound by their rules, not just the law. Want to paint your walls a bold color? You might need written permission. Want to install a new kitchen? You’ll need approval, and you might have to use their preferred contractors. Want to keep a pet? Some associations ban them outright, even if you’re only owning 25% of the home.These aren’t minor inconveniences. They’re constant friction points. One buyer in Wellington spent six months trying to get permission to replace a broken boiler because the housing association insisted on using their own, more expensive provider. By the time it was fixed, the original quote had doubled.
Staircasing isn’t free-unless you like paying for the same thing twice
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 another share, you pay for a new valuation. And those valuations? They’re not cheap. In Auckland, a single valuation can cost between $500 and $1,200, depending on the property size and the surveyor’s availability.And it gets worse. The housing association sets the price for each share you buy-not the market. So if property values rise, you’re locked into paying more to climb higher. One family in Christchurch bought 50% of their home for $280,000 in 2021. By 2024, the full market value was $520,000. To buy the remaining 50%, they had to pay $260,000-despite having already paid $280,000 for half. They didn’t get a discount for being long-term owners. They just paid market rate for the rest.
Reselling is harder than you think
If you ever want to move, you can’t just list your home on Trade Me. You have to go through the housing association’s resale process. They get first pick. If they can’t find someone eligible for shared ownership, then-and only then-can you try selling on the open market.That means your pool of buyers is tiny. Most people can’t afford a full home but also can’t qualify for shared ownership because of income caps, credit history, or existing debt. So your property might sit unsold for months. One buyer in Dunedin waited 11 months to sell their 60% share. During that time, they were still paying rent on the remaining 40% and covering all maintenance costs. They lost over $4,000 in extra rent alone.
You pay for everything, but you don’t control anything
You’re responsible for repairs, insurance, service charges, and ground rent-even though you don’t own the whole thing. That’s not a bug. It’s the design. In shared ownership, you’re treated like a homeowner for costs, but like a tenant for control.Service charges can spike without warning. A roof repair in Tauranga last year cost residents an extra $380 per year, even though the building was only 12 years old. No vote. No say. Just a letter in the mail. And if you fall behind on payments? Even one missed rent payment on your unsold share can trigger eviction proceedings. You can lose your home even if you’ve paid $200,000 toward your share.
Interest rates hit you twice
You need a mortgage for your share. That’s obvious. But here’s what most people miss: you also pay rent on the portion you don’t own-and that rent can go up. Usually, it’s tied to inflation or the Retail Price Index. In 2024, rent increased by 6.8% across New Zealand. That’s more than double the average wage growth.So you’re paying mortgage interest on your share, and then you’re paying rent that rises every year. That’s two financial pressures, both tied to interest rates and inflation. One Auckland couple found their monthly payments jumped from $1,850 to $2,120 in just 18 months-not because they bought more shares, but because rent went up. Their mortgage stayed the same. The rent didn’t.
You’re not building equity like a real homeowner
It’s easy to think that because you own a share, you’re building wealth. But you’re not. Not really. You’re paying down a mortgage on a partial asset, while the rest of the property is owned by a landlord who doesn’t pay a cent toward upkeep.When you sell, you only get back the value of your share. If the house goes up 20%, you get 20% of your share’s value. But if the house needs a new roof, you pay 100% of the cost-even if you only own 30%. That’s not equity building. That’s a one-way street where you pay more, gain less, and have zero control over the asset’s condition.
There’s no safety net
If you lose your job, get sick, or face a family emergency, you can’t just pause your payments. You’re expected to keep paying both your mortgage and your rent. There’s no government relief program for shared ownership residents. No mortgage holiday. No rent freeze. Even if you’re on a benefit, your shared ownership agreement doesn’t recognize hardship.One woman in Hamilton lost her job during the 2023 recession. She couldn’t pay her rent share for three months. The housing association started eviction proceedings before she even got her first benefit payment. She lost her home, her deposit, and her savings.
It’s not a stepping stone-it’s a trap
The biggest lie of shared ownership is that it’s a path to full ownership. For many, it’s a trap. The costs, the rules, the lack of control, and the slow climb make it harder to leave than to stay. People end up stuck for years, paying more than they would for a rental, with less freedom and no real ownership.Before you sign, ask yourself: Are you buying a home-or are you buying a long-term rental with a mortgage attached? If you’re not sure, you’re not ready.
Can you ever fully own a shared ownership home?
Yes, in theory. You can buy additional shares over time until you own 100%. But in practice, many people never reach that point. The cost of each valuation, rising rent, and lack of financial flexibility often make it unaffordable. Some housing associations even cap how much you can buy at once, forcing you to wait years between purchases.
Are shared ownership homes cheaper than renting?
Not always. In many cases, your total monthly cost-mortgage + rent + service charges-ends up being higher than renting a similar property privately. One 2024 study in Auckland found that shared ownership residents paid 18% more per month than those in comparable private rentals. The difference? Rent increases, service charges, and mandatory insurance.
Can you make improvements to your shared ownership home?
You can, but only with permission. Major changes like extensions, new windows, or structural work require written approval. Even small things like replacing kitchen cabinets or installing a new bathroom can need sign-off. Some associations require you to use their contractors, which can cost 20-40% more than hiring your own.
What happens if I want to sell but can’t find a buyer?
The housing association gets first right to find a buyer. If they can’t find someone eligible for shared ownership within a set time (usually 3-6 months), you can list it on the open market. But your buyer still needs to qualify for shared ownership. That drastically reduces your pool. Many properties sit unsold for over a year, costing you hundreds in extra rent and maintenance.
Is shared ownership a good option for first-time buyers?
It can be-but only if you understand the long-term costs. It’s not a shortcut to homeownership. It’s a complex financial arrangement with hidden fees, limited control, and no safety net. If you’re planning to stay for 10+ years and can handle unpredictable rent hikes, it might work. But if you need flexibility, mobility, or financial breathing room, renting or saving for a full deposit is often the better choice.
If you’re considering shared ownership, talk to someone who’s been stuck in it for five years-not the sales rep. Ask them about the surprise bills, the delays, the stress. The truth isn’t in the brochure. It’s in the quiet stories of people who thought they were getting a home, but ended up paying for a lease with no end in sight.