Home Improvement Loan - Any smarter way?

Hi,

I'm in the process of closing a deal on a 1980s house and I decided to go with the max mortgage available of 92% due to be drawn down in the next few days.

The thing is I want to build a small kitchen extension extension (ca 100 sqft), refit and tile the bathroom, and put in a downstars loo under the stairs almost immediately.

I've been told I can't wrap this into the mortgage so I was going to borrow 30K from Tesco at 6.9% APR.

I can manage the total monthly spend alright, but I was just wondering if I'm missing a trick and doing this a daft way?

You could try:

1. Save the money and then do the extension or
2. Buy the property, then get pp if necessary, then remortgage to do the extension.