A typical Victorian terrace can be converted to two rooms and an en-suite. That is a three bed to a five bedroom house with two bathrooms for around £40,000 which is a no-brainer in London. Going from a two bedroom house in parts of London to a four bedroom can be a difference of £300,000. An attic conversion is the most cost effective way to add value to your home. The recent property market in London has shown unprecedented growth so a loft conversion has never been a better option.