What is the minimum share I can buy when staircasing?

Staircasing is the process of buying more shares in a home you already part-own, until you own all of it. The smallest extra slice you can buy depends on which version of shared ownership your home was sold under. On the newer national model, the minimum additional purchase was reduced from 10% to 5%¹. Homes sold under older leases often still set a 10% minimum, so the lease, not a general rule, decides your case.

There is a second, smaller route. New shared owners can buy additional shares in 1% increments for up to 15 years, with heavily reduced fees¹. That is designed to let people build up their share gradually without paying for a valuation each time.

Once you own 100% of the property you pay no rent at all, because rent is only charged on the share the housing association still owns². Each step you buy cuts the rent on the remaining portion.

Minimum staircasing share: 5% on the new model, 10% on older leases

The rule that matters most is written into your lease. Under the new national model for shared ownership, staircasing transactions other than the 1% route were reduced to a minimum of 5% rather than 10%⁴. The same change is described in the model's own terms: the minimum additional share purchase was reduced from 10% to 5%¹.

That does not rewrite older agreements. A shared ownership lease sets out the smallest share a leaseholder can buy at a time, and homes sold before the change keep the terms they were sold with. If your lease says 10%, that is the floor for you unless your housing association agrees otherwise.

The 1% route sits alongside the 5% rule rather than replacing it. New shared owners can buy additional shares in 1% increments for up to 15 years, with heavily reduced fees¹. After that window, the standard minimum applies.

Different schemes set their own floors, which is why the answer is never universal:

In Northern Ireland, Co-Ownership sets its own floor: you can buy more shares in your home at a minimum of 5%, subject to affordability⁵. Its staircasing process works in set amounts, typically 5%, 10%, 20%, or buying out the remaining share in full⁹.

Buying 1% a year for the first 10 years without a valuation

The 1% route is the part of the new model that changes what is practical for people on modest budgets. New shared owners can buy additional shares in 1% increments for up to 15 years, with heavily reduced fees¹. Because the fee is heavily reduced, the usual cost of a fresh valuation for each purchase largely falls away during that period.

The trade-off is time. Buying 1% a year is a slow path to full ownership, and the price of each 1% is based on what the home is worth when you buy it, so a rising market means each slice costs more than the last. The 1% route also has a time limit: it runs for up to 15 years, after which the standard minimum applies.

Outside that window, a valuation is normally part of the process. Guidance for shared owners in England describes 5% steps, or 1% a year for up to 15 years, with 5% and larger purchases requiring a valuation and an admin fee¹⁰.

Some schemes charge a flat valuation fee rather than a full survey cost. Co-Ownership in Northern Ireland charges £75 per staircasing transaction⁹.

How your rent falls as your share rises

Rent is charged on the part of the home you do not own. Buy more of it, and the rent falls. Co-Ownership puts it plainly: each time you buy more, the amount of rent you pay each month goes down because you own a bigger portion¹¹.

The standard shared ownership lease says the same in legal terms: as the leaseholder buys further shares, the rent will be reduced proportionately to reflect the fact that the landlord's share has shrunk¹².

The same principle runs through the government-backed schemes. Under the Right to Shared Ownership, you can buy more shares in the future, known as staircasing, and pay less rent on the rest of the property³. The Older Persons Shared Ownership scheme and the HOLD scheme for people with a long-term disability both state that if you buy more shares, you will pay less rent¹³.

At the end of the process the rent stops entirely. If you choose to buy the remaining amount, you will own 100% of the property and won't pay any rent². Service charges and other costs of the home continue, because those are separate from rent.

One protection is worth knowing about. The standard lease caps how much the rent can rise in a year when inflation is flat or falling: where the RPI is zero or negative, the most the rent can increase by is 0.5%¹².

What staircasing costs: valuation, legal fees and permission from the housing association

Staircasing is not free, and the costs sit with you rather than the housing association. Under the Open Market Shared Equity scheme in Scotland, you pay all the valuation and legal costs as well as the administration costs of the organisation handling the request¹⁵. The New Supply Shared Equity scheme uses the same wording: you have to pay all the valuation and legal costs to do it as well as the administrative costs of the organisation that will handle your request⁶.

The Right to Shared Ownership guide gives worked examples of what a share costs at different sizes, based on a full market value of £425,000 at the time of staircasing¹⁶:

Where the detail lives: all of the details about the cost of this process is available in the lease, the housing association provides details on the costs, and the shared owner's solicitor can advise¹⁷.

Permission is a separate step. Check with the company that owns the rest of the home first, as you will need their permission¹⁸. Some homes carry a restriction that caps staircasing at 80%, which applies to shared ownership homes in a Designated Protected Area¹⁹.

From your first share up to 100% ownership

Most shared owners start with a share somewhere between 10% and 75% of the property and pay a reduced rent on the rest to a housing association¹. From there, the route to full ownership is a series of purchases.

The shape of that route varies by scheme:

• New national model: 5% steps, or 1% a year for up to 15 years¹⁰
• Co-Ownership, Northern Ireland: small 5% steps or more, all the way up to full ownership²⁰
• First Homes Fund, Scotland: at least 5% each time, and once you own 90% or more you can only increase your share up to 100%⁷
• New Supply Shared Equity, Scotland: at least 5% in a year, and in most cases you can increase your share all the way to 100%⁶
• Open Market Shared Equity, Scotland: a minimum 5% increase where there is no golden share⁸

The 90% rule in the First Homes Fund is worth noting because it changes the arithmetic near the end: if your share is already 90% or more, any further increase must take you to 100%²¹. You cannot creep up in small steps once you are that close.

Shared equity schemes generally allow staircasing up to 100%, so that if you sell your home, you will not owe anything to the government²². That is the point of reaching full ownership: the housing association's share, and its claim on the value of the home, is gone.

You do not have to reach 100% before selling. The landlord's right of first refusal does not apply if the lease is transferred or assigned as a result of the divorce or death of the leaseholder, or after staircasing to 100%¹². In other circumstances the housing association normally gets first refusal, which is covered in more detail in selling a shared ownership home.

Where the money comes from: deposit and mortgage on each step

Each purchase of extra shares is normally funded the same way as the first one: a deposit plus a mortgage, or savings if you have them. Deposits are calculated on the share you are buying, not the whole property. Shared ownership homes can be purchased with a deposit of at least 5% of your share of the property and a mortgage to cover the rest¹.

Under the Right to Shared Ownership, you will also need to pay a deposit, usually between 5% and 10% of the share you're buying³. In England the minimum initial stake you can purchase is 10%, but many schemes require you to buy at least 25%²³.

The deposit rules for a standard mortgage give useful context for what lenders expect. It is possible to get on the property ladder with a deposit of 5% of the purchase price and a mortgage covering the rest²⁴. One building society sets its own floor at 5% of the purchase price or value of your property, whichever is lower²⁵.

If you fall behind on rent or mortgage payments on a shared ownership home, the options and the protections are set out in what happens if a shared owner falls behind on rent.

Where to get help

Free, impartial guidance on shared ownership and staircasing is available from several places. Your housing association is the first point of contact for what your lease allows, what a share will cost and what permission is needed. A solicitor can advise on the lease terms and handle the legal work.

For general help with money and debt, including mortgage arrears, free advice is available from charities such as StepChange. The MoneyHelper service offers free guidance on mortgages and home buying.

If a dispute with your housing association cannot be resolved, the complaint routes for housing associations and for financial firms differ, and are covered in complaining when buying a home goes wrong.