T he cost of renting has been rocketing. According to the latest figures from the HomeLet Rental Index, the typical UK rental property now costs 826 a month while those in London are an average of 1,297. These eye-watering sums are only set to increase – by 2020 rents will be 46% higher than they are today, according to the National Housing Federation. David Orr, chief executive, says: For decades we simply haven't built enough homes, resulting in a dysfunctional housing market with inflated costs.

But there are ways to cut those costs – and you don't have to slum it to do so. A room in a stately home could be yours for 55 a week, and that's just one of the options for those willing to eschew typical rental arrangements.

Property guardians

You could choose to be a property guardian in one of the thousands of empty properties around the country – from fire stations, vicarages, pubs, care homes and old schools. In exchange for keeping an eye on the building, guardians benefit from rock-bottom rent. Ad Hoc Property Guardian, for example, currently lists several hundred properties in the UK with rents ranging from 150 to 450 a month.

As with a standard rental agreement, you will pay a deposit and sign a contract. Provided you have proof of earnings that will cover the cost, you are allocated a room or property in an area to suit you.

Kate Williams, 27, a freelance writer and musician, pays around 240 a month, including bills, to live in a 25ft-square room in Delapre Abbey, a country estate near Northampton complete with stained-glass windows, grand staircase and surrounded by around 500 acres of parkland. It's managed by Camelot Property, which says guardianship is most popular among key workers and people in their 20s and 30s faced with unafforable rent.

There are around 10 guardians in the property in total, says Williams. I knew a few people who lived in the property before so was really pleased when a room came up – obviously it has masses of space which is great for me as I work from home.

The guardians have a bedroom to themselves, but share other facilities. Williams adds: A downside is that the building is so old that maintenance can be an issue – we didn't have any hot water for two weeks last winter as the pipes froze. Also, guardianship can't last for ever; landlords only need to give two weeks notice. I am trying to save as suddenly I might have to find the money to pay for rent in a 'normal' house, says Williams.

Homeshare

Charities are bringing people together who may not have previously considered co-habiting. Crossroads Care, for example, matches older homeowners who have a spare room with younger people who can offer practical help in exchange for a low-cost place to live. In return for a below-market rent the sharer is contracted to spend 10 hours a week providing companionship and helping out with household chores.

Ivana Sujova, 27, recently moved into a three-bedroom flat in Swiss Cottage, north-west London, with a 91-year-old woman. She pays 200 a month, including bills. I've done homesharing for two years in different homes, she says. I moved in with my boyfriend for a while, but things changed and I needed to find another place. Sujova adds: While I work full time I couldn't possibly afford to rent a room or flat in London on my salary, and I think the arrangement is amazing – I love my new friend already, and she has so many stories to share.

Sujova often spends evenings cooking with her elderly housemate, and will do the shopping. Making up the 10 hours a week is easy. By the time I've come home and we've chatted, the time flies. She didn't pay a deposit but there is a minimum stay of six months. Applicants complete an online form and will then be invited for interview.

Lodgers

Choosing to share a home someone owns can be cheaper than a house share. Rents are typically advertised on an all-inclusive basis and because you live with the landlord the property is more likely to be well-kept with maintenance issues dealt with quickly.

Kelly Jameson, 27, a freelance photographer's assistant, lives in Chiswick, west London, paying 525 including bills for a room in a three-bedroom house. She's been living with a married couple in their late 40s for the past 14 months after seeing the property on SpareRoom.co.uk. When the couple travel, Kelly looks after their dog, cat and the house. In return, they've agreed to charge me just 100 rent when I go away for a month in September, she says. She adds that the best thing about being a lodger is having one payment each month. I don't have the hassle of calling utility companies, which is a relief. However, the downside is not having a space that's truly her own, although it is much homelier than the houseshares I've lived in . She plans to stay put while she saves to buy her own place.

However, bear in mind that as a lodger the balance of right is in the landlord's favour, as the flat or house is their main place of residence. It also means that the landlord only needs to give reasonable notice to ask a lodger to leave. While typically 28 days, this could be shorter.

The landlord also doesn't have to hold any deposit in a protection scheme. While a tenant has exclusive use of space they rent during the tenancy, a lodger doesn't. Yet tenants have more responsibilities than lodgers, including looking after the property and paying utility bills.

■ Contacts: SpareRoom.co.uk ; uk.easyroommate.com