New builds are just a terrible idea.
They are built on dodgey groundwork (8 houses recently collapsed on a newbuild estate round here, and not so long ago 4 on a different one). And the estates are laid out as follows: Roads of the minimal width possible in order to cram as much in as possible, no usuable front garden - you may be lucky enough for a parking space MAYBE. And when you buy the house you'll be overlooked from every angle - invest in some net curtains because developers don't care if your neighbour can see in the bedroom. It's almost a certainty your garden won't be remotely private if you have a usable garden.
So thats the ground, from the ground up you have a themalite and timber framed house (not even close to being as durable as brick or stone) which has insulation and windows at the legal minimum limit. Often there is minimal soundproofing between houses and everything only just about meets regs. All of this is put together by unskilled polish builders who take a "**** it that'll do attitude" and work to a price making sure everything is rushed. Inside you can look forward to steel framed stud walls and dot and dob on external with tape and filled boards. Which you can't fix to and the soundproofing is next to zero, not to mention if you fix into the thermalite block you'll invalidate the terrible hom****** warranty. The finish will likely be low quality laminate, cheap timber painted in satinwood and magnolia walls throughout, oh yes, it's that tacky.
You'll also not be able to board your loft or us it for storage, one because it won't be built for it, two because it'll invalidate your warranty.
Now for finances, if you're buying a new build you'll almost instantly be locked into negative equity when you buy it because it will drop in value fast. What will aid in this is that social housing is required to be on the same estate - which brings less reputable characters and also the fact pretty much anyone can buy part buy part rent or on homebuy scheme so anyone could be moving in.
When pricing it up and comparing it, compare prices to the rough areas in your town, because the potential to develop into a rough area is very real. You have no idea what the area of the estate is like, and visual indicators are a no no, because they will have restrictions until selling the last house - not vans, no satellite dishes, nothing to make it look scruffy. All lifted when the last house sells and then the developer will bugger off never to be heard from again.
They're such bad quality, everyone I know who bought one, has regretted it.