On my Buy to let mortgage, I had to place a deposit of 30%. The interest rates were slightly higher than a traditional mortgage also.
I think what you're planning to do is VERY wise, you will be laughing in the future once you've got 2 properties paid off (the rented one should pay for itself anyway, so there shouldn't be a financial burden on that property, other than the initial deposit.).
I would strongly recommend you go for an 'interest-only' mortgage, this will ensure you are not paying more than you can afford on a monthly basis (as you have 2 mortgages) and if anything would happen with your current income, you will not be hit as hard and still be able to cope with the payments. An 'interest-only' mortgage should have very low monthly instalments, your rental income should cover it and give you a small amount of profit on top, allowing you to make over-payments at the end of the year (a lot of mortgage companies allow up to 10% overpayment without being penalised).
Personally I'd say that advice is a little dangerous Haz but as said.......ask Sarnie for professional, qualified advice.
Your confusing yourself by using the term 'deposit'. When you own the property already its simply a case of the having the correct 'loan to value - LTV'. Your talking about doing a capital reduction but again this is a little confusing as you need to pull money out of the current property to fund the deposit on the new one.
For example
Current prop value
£220k
Current mortgage
£140k
Savings in bank 20k
New property value
£220k
Mortgage max LTV 75%
Max mortgage therefore £165k
Deposit required £55k
You have £20k in the bank and therefore require an additional £35k from the equity of £80k in the current residential.
There are 2 options
1. Existing mortgage company offer you a 'Further Advance' of £35k (taking total outstanding balance to £175k) - subject to max LTV, lending criteria, affordability critiera, consenting to you letting the property.
2. You remortgage to another mortgage company for a BTL mortgage of £175k (£140k to redeem existing and another 35k for the new purchase).
Mortgage companies assess BTL lending on 1 or 2 ways;
1. Rental yield as a % of cover for the installment - eg installment is £500 and rental is £700 you have a 140% rental cover. Lenders might set the threshold at say 125% cover (i.e you need at least 125% cover to get the mortgage you want - based on a RICS qualified surveyors assessment of the projected rental).
2. Based on your income (usually with a deduction of a set % off your income of whatever you residential mortgage balance is)
Be sure about being a landlord though mate - it can be an unholy ball ache and don't forget your going to be in for a cool £340k of secured debt. You have tenants who can lose their jobs too, then your stuck making the payments to the mortgage, you are liable to sort all of the damage, ensuring the property is compliant. If its not the council can serve you with improvement notices that they will simply act upon themselves if you fail to comply (then register a landcharge on your property).
However - you could end up with a nice little nest egg for retirement and some tasty profit off the tenants.
Bottom line SPEAK TO SARNIE
Do you want a job?
All of the above is accurate. However there are still many many pitfalls to BTL mortgages as opposed to residential lending. Almost every lender has there own criteria to satisfy. Northern Rock for example require you to have six months worth of mortgage payments sitting in an account as a contingency fund.
Some will require you to have had tennant for six months before lending to you. Also the reason for the extra borrowing will rule out some lenders............
It's a minefield