Matrimonial home in one name prior to marriage

I am in the process of a divorce but I am confused as to the actual liability I have to my wife. I purchased a house in my name before we were married at £48000 which we lived in before we married two years later. During that period the prices rose dramatically. The house is now worth at least £90000. My wife seems to have the impression from her solicitor that she is entitled to 50% of an equity pot that she estimates around £50-60000 and expects to pay nothing toward the sale of the house or for living it while we are pending divorce.
My solicitor is advising me that the calculation should be based from the date of the marriage not the date i mortgaged and that I should be entitled to half payment for the mortgage since we split as she is still living in the house.
This was a short marriage of two years 4 months although we were in a relationship prior to that and co-habiting. She never contributed to the mortgage or main utility bills on the house during the marriage or during the cohabiting but gave £800 as down payment on house and spent £1000 on home improvements. I spent the proceeds from my previous relationship of 16 years (£6000) on home improvements. We have no children together and her children will both be over 18 by the time this goes to court.
What is the bottom line likely to be in this scenario? Can anyone shed some light onto which of our solicitors is likely to be incorrectly advising us as they both can't be right. My solicitor has advised me to make her an offer of no more than £16000 and she has refused that.

There is room for interpretation and at the end of the day only a judge's decision is binding. Your lawyer is arguing only the marriage counts but recently the courts have been prepared to treat a period of pre-marital cohabitation as part of the overall duration of the marriage if the couple have moved seamlessly from living together into marriage.

Also your sol will give an opinion on what he considers the best outcome is for you and your wife's sol will give his opinion according to the best outcome for her so in reality the position is usually somewhere in the middle. I'd suggest compromising and trying to resolve matters through mediation or collaborative law.

This article will shed some light on the issue:

www.manches.com/practices/family/article.php?id=83