I bought it new at the end of 2014, I liked it because the kitchen is a decent size as is the living room. New houses around the same size around here go for well over £300k.
You can't really compare it to a new house now though. It's cleared not new (as you are selling) - buyers won't be able to pick the spec they want, have a warranty, choose a plot, get developer contributions which assist with low deposits, new buyers often feel 'safe' when having their hand held by a developer and inhouse legal teams etc....
Unfortunately (and please don't take this is a personal criticism to you or your house, it's not intended that way in the slightest) your property falls into the trap of being something that both main groups of buyers will try to avoid.
If the buyer is attracted to a new house (or something very modern) they are probably much better off buying new (like you did).
If the buyer doesn't want new (me for example) then your house represents everything they will try to avoid - it's overlooked, it's copy and paste design around the estate and country, the parking situation is odd (with no driveway and photos showing other cars parked metres from your windows), the family bathroom has been severally compromised so that an en-suite can be included, it's not a genuine 4 bed house - I'd class it as a 2 bed with 2 upstairs offices, the garden is small, it's 'detached' but only gains the benefit of reducing neighbours internal sound (you'll still hear them pull up, walk to their door, access to the side is limited, no land for you to mark as your own etc...), the garage probably isn't much use and could potentially be liability, your front door opens directly onto what looks like a road (or at least somewhere where random cars can park), there is no room to expand or extend aside from the loft, the bathroom spec looks cheap / bland and nearly everything is magnolia. Obviously you get these with a new house but you also get the benefits that come with a new house.
Again, please don't take the above personally. People who want moderns will buy a new build, people who want to avoid modern (and the mentioned issues that come with it) will buy something built between 1950 and the late 1990's. You are left with a smaller subset of people that the house will appeal to.
If the house isn't selling it's almost down to money and time. Your house may be worth it's asking price but probably to much smaller group of people than a new built, so if you want that price you may need to wait until someone from the group who will be happy with it is ready. The other option is to reduce the price so that it falls into bargain territory - people will compromise once it gets to a point that it's significantly cheaper than what they want.
The above is all honest feedback from someone who watches the housing market very closely, not meant the offend.