Time to remortgage - but how do I know what my house is worth?

timefortea

I bought my house almost two years ago, so now my two year fix is coming to an end. I used a mortgage broker as a FTB and will be speaking to him again, but in the meantime I've been looking at online calculators to get an idea of what deals are out there. I'm confused about the value of my house though. I bought it at £140k and am currently with Nationwide. When I looked at their house price index calculator it said the value of my house should've gone up by 2.59%, but when I logged into their online switching portal it gave my house a value of £130k, with no explanation of the drop. If I overpay as much as I can right now and my house price has gone up by even just £2k I'd be in a lower LTV bracket so the value I enter into calculators is making a big difference to the results I get back. Do you have any read on whether someone who bought their home two years ago (old house, not a new build) should expect the value to have increased, decreased, or stayed the same?

I haven't done any major work to the house that would change the value, the biggest thing I've done is pay £2k for a lead roof on my bay window.

I did try to call Nationwide today to ask but after I'd waited on hold for ages then asked my question the line suddenly went dead. It felt like a deliberate hang up and I decided not to call back. 

Thank you  

timefortea

I have an update if anyone is interested. I rang Nationwide and asked if I could appeal their valuation. They asked me for basic details about my house, the number of bedrooms, any extensions, whether I've done any work on it since buying, and what I think it's worth. I gave the value from their own house price index calculator (link above). That was on Thursday, it was supposed to be going to an underwriter who'd email me the outcome at the beginning of this week. I still haven't had an email but today (Monday) their valuation was changed from £130k to the figure I gave, so its gone up by over £12k with no quibbling by them. I'm surprised it was that straightforward but obviously pleased.