50K deposit for house

Because if your interest payments are higher than the equivalent amount you'd pay in rent; you're worse off. Effectively the bank is your landlord.

the amount paid towards interest

You don't sound too knowledgable yourself. My parents have taken out several buy to let properties, all with 25% or less deposit, and banks are much more cautious about authorising these. When I graduate, I will be aiming to buy my first property as soon as I possibly can with the minimum deposit so that I can get on the ladder, start gaining equity, and save towards building my portfolio. Also my salary will go up every year or two but the amount I owe on the house will go down. I'm not going to mess around saving up far more than I need to for my new pad.

Also to the OP, it really depends on yours and your partner's salaries. I'm assuming you have half decent jobs if you've saved this much up, but that is what the bank will consider when they calculate how much they can lend you. Outstanding debts such as student loans/car finance or whatever are also considered in your affordability calculation so now isn't a great time to buy a new car. But 50k is a great deposit for your first house (70 even better!), so you are in a good position. So essentially the amount you can/should borrow really depends on your salary. Remember to allow enough money to cover all fees as well as this can be quite a few thousand.

Buy to let mortgages are different to ordinary residential ones, hence the lower deposits being less of an issue in a buy to let mortgage. Do not confuse the two as you seem to have done.

I'm not confusing the two, I'm saying it was easy for them to get one putting down 25% of the property's value as a deposit. Buy to let mortgages are much harder to get, so there's no reason someone shouldn't be able to get a mortgage for their personal house with a 10% deposit (providing they have a salary with which they can afford repayments).

I never claimed you can't get a mortgage with a 10% deposit, I simply said the rates are substantially worse so 20-25% is really where you'd ideally be aiming for.

Buy to let mortgages are actually easier to get really, as all that matters is that the rent covers the monthly payments. If this is met they don't even need to look at your income or take into account other debts you hold. How do you think people build up buy to let empires worth millions where their equity is only 10-20% of each property?

Yes but you need to show that you have sufficient means to prevent the property being repossessed in the event that it is not being rented.

No rental property is occupied 100% of the time, people move out etc, and you need to find someone to live there in the first place after it has been purchased. In the vast majority of cases you'd need to put a 25% deposit down, but if you already have an empire build up then obviously banks will be more willing to lend to you as overall you have a lot of assets/equity.

Also it seems as if the OP is quite young and this is a first property purchase, so he/she could use the help to buy scheme with 5% deposit, which I will almost certainly be taking advantage of at some point as well.

Good advice.

Is this sarcasm? Some people would struggle for years and years even to raise 10% on a modest flat/house. I utterly refuse to burn money every month renting someone else's property, it's a great way to help young people on low salaries onto the property ladder. What's the problem?