The figure on a property advert is not always the figure you need to fund. With a shared ownership mortgage, you usually buy a percentage of a home and pay rent on the part you do not own. That can make buying more achievable than purchasing the whole property outright, but it also means looking beyond the mortgage payment before deciding what feels affordable.
For many first-time buyers, the appeal is clear: a smaller deposit and lower initial borrowing can bring a suitable home within reach. The right choice still depends on the full monthly cost, the lease terms and your plans for the years ahead. A mortgage adviser can help translate those details into a clear, realistic budget before you commit.
How a shared ownership mortgage works
Shared ownership is normally offered through a housing association. You purchase an initial share of a leasehold property, often between 25% and 75%, using a deposit and mortgage. The housing association retains the remaining share and charges rent on it.
For example, if a home is valued at £280,000 and you buy a 40% share, the share you are buying costs £112,000. Your deposit is calculated against that £112,000 purchase price, not the full value of the home. You would arrange a mortgage for the rest of your share, then pay rent on the 60% owned by the housing association.
You will generally also pay service charges, and potentially other estate-related charges. These can contribute towards communal repairs, building management, insurance arrangements and maintenance of shared areas. The exact costs depend on the development and lease, so they need to be included in your affordability calculations from the start.
Your monthly costs are more than the mortgage
A lower mortgage payment can be helpful, but it is only one part of the picture. Your regular outgoings may include mortgage repayments, rent to the housing association, service charges, council tax, utilities and contents insurance. Where applicable, you may also need to budget for ground rent or other charges set out in the lease.
It is worth asking for an illustration of current rent and service charges, alongside information about how they can change. Rent may increase under the terms of the lease, while service charges can rise if the cost of maintaining the building or estate increases. New-build developments in particular can carry charges that first-time buyers may not have encountered before.
A lender will assess whether you can afford the mortgage, but your own budget should go further. Consider what would happen if your household bills increased, your income changed or you needed to meet an unexpected cost. Buying a home should leave room for living, saving and enjoying it too.
Deposit, eligibility and lender criteria
The deposit needed for a shared ownership purchase can be lower in cash terms because it is based on the share you buy. A 5% deposit on a £112,000 share is £5,600, for instance. However, the deposit size and mortgage options available will depend on your circumstances, credit profile, income and the lender’s criteria.
Not every mortgage lender works with every housing association, property type or shared ownership scheme. Some lenders may have requirements around the minimum share you can buy, the remaining lease length, property location or the level of service charges. Flats, new-build homes and properties above commercial premises can all need additional consideration.
Eligibility rules for the scheme itself also apply. These can vary by location and provider, and usually consider your household income, whether you already own another property and your ability to afford the purchase. Schemes and criteria can differ across the UK, so information that applies in one nation or local area may not apply in another.
This is where personal advice can save time and unnecessary applications. Rather than comparing headline rates alone, an adviser can assess the property, your intended share, deposit and wider finances before approaching suitable lenders.
Check the lease before you fall in love with the property
With leasehold property, the lease matters as much as the home itself. It sets out your rights and responsibilities, including how rent is reviewed, what service charges may cover, whether you can keep pets, make alterations or let the property, and the process for selling.
Pay close attention to the remaining lease term. A short lease can affect mortgage availability, future saleability and the cost of extending the lease. Your conveyancer will review the legal detail, but it is sensible to raise questions early if anything is unclear.
You should also understand who is responsible for repairs. You will usually be responsible for maintaining the inside of your home, while the housing association or managing agent may be responsible for the building and communal areas. That does not mean costs cannot come back to leaseholders through service charges, particularly for major works. Ask whether there are any planned projects or expected increases that could affect your budget.
Think ahead: staircasing and selling
Many shared ownership leases allow you to buy further shares later, a process known as staircasing. If your income rises, savings grow or the property increases in value, this may give you the option to own more of the home and reduce the rent you pay on the remaining share.
Staircasing is not automatic or cost-free. You may need a valuation, legal work and possibly a further mortgage application. The price of additional shares is normally based on the property’s value at that time, which could be higher or lower than when you bought. Some leases also place limits on the maximum share available to buy, so do not assume you will always be able to reach 100% ownership.
Selling can involve a process set by the housing association. In some cases, it may have a period in which it can nominate a buyer before you market the home more widely. This can support the scheme’s purpose, but it may affect the sale timeline. Understanding these conditions before purchase helps you make a decision that fits your likely plans.
Questions to ask before making an offer
Before reserving a property, make sure you can answer the practical questions rather than relying on a monthly mortgage illustration. Ask what share you are buying, how much rent is payable on the remainder and when that rent can increase. Confirm the current service charge, what it covers and whether major works are planned.
Ask for details of the lease length, staircasing rules and resale procedure. If the property is new-build, check the expected completion date and how long your mortgage offer needs to remain valid. Delays can happen, and it is better to understand the process before paying reservation or legal fees.
You should also ask how the housing association calculates the property value and whether your financial position supports the total cost, not simply the mortgage. A clear answer now can prevent pressure later.
Getting mortgage advice that fits the whole purchase
A shared ownership mortgage is not just a smaller version of a standard mortgage. The lender needs to be comfortable with the property and lease, while you need confidence that the combined costs work for your household now and in the future.
At CoG Financial, a named adviser can look at your income, deposit, credit position, the property details and the costs set out by the housing association. Supporting documents can be supplied electronically, while you still have a real person available to explain what is happening and what is needed next.
Mortgage lending is subject to eligibility, affordability checks and lender criteria, and your home may be repossessed if you do not keep up repayments. The most helpful next step is to get the figures in front of you early, then speak to an adviser before a property reservation turns an exciting opportunity into an avoidable financial stretch.