Lovely house, honestly. Why is your friend leaving?
BUT
It’s over priced in this market. Many detached, large houses are just not selling in most places.
Now use the mortgage calculator at the bottom of the page: imagine a buyer with max 20% deposit coming along (10% is more realistic). Then change the mortgage term to 30 years. Keep the rate at 6%. Now can you see how much this house is really costing someone?
It’s also over priced for the area. The main road doesn’t look great in the photo of the front of the house tbh. It’s near an A road too. Can the road be heard? Has your friend not read in recent news about pollution harming people (Ulez)??
People want something for their money right now. In addition, you have more millenials and some gen z in the market. They are a different type of buyer. They want quality, substance, something that makes financial sense given the shit they’re putting up with (low wages, crap pensions, born into a crappy world). Imagine the entire roof needs replacing on such a large house, it would cost a lot, why would anyone want to buy such an expensive house when it’s actually a money pit in today’s market.
This is the future of the market. Millenials and Genz Z know it.
Also, I just realised your friend bought it only a few years ago for 380k. Why is it 600k now? What justifies that? Nothing as far as I can see. As a buyer, I’d laugh because I’d think your friend is deluded and would be a difficult seller that I can’t be bothered with. Then I’d just move onto the next property.
Your friend will have to keep reducing the price until someone finds it attractive enough.