Seascape, that's an interesting point about the chances of planning consent (although I disagree that Regs have now made all houses 'eco'!).

I asked my planning officer this very question (would I be more likely to get planning permission for an eco house). Was told "No, because all houses must be sustainable these days". That was 8 years ago.

Resurrecting this (again!) as we're about to put an offer in on a plot of land for our PassivHaus self build in the South West of England. I'd appreciate thoughts on how we might work out what to offer.

Facts:

Outline planning consent granted for 2 storey, 4 bed detached house (quite mean for a 4-bed at 96 sqm) on 300sqm plot. Agreed Scale and Massing only.
(previous application for 2 buildings was refused so we won't be challenging this)
Not in AONB or conservation area
Not in floodplain or area of subsidence, radon etc. according to Env. Agency
Completely empty site (other than some boundary walls) since 1970's demolition of old cottages
Consented plot layout is for South West facing garden (plenty of solar gain looking at Streetview)
Wayleaves/underground services currently unknown

We may face some challenges on materials/appearance due to Victorian streetscape but I think we can negotiate on this - reading the case officers grounds for refusal of previous application suggests they are prepared to accept a 'contemporary interpretation' of context.

A developer is intending to build on a larger adjacent plot but has already had 2 applications turned down due to scale and (pastiche) appearance. There's still a risk it might become overrun with Barratt boxes, but we should be relatively sheltered by the boundary wall!

Any rules of thumb (total budget/market return * pi/ golden ratio etc.) or things to watch out for gratefully received..!

ST,

That's a tricky one as there haven't been that many plots sold around the area recently. I can't find the details of the adjacent larger plot either.

According to recent land registry sold prices, the average 3-bed is worth £200-210k and the average 4-bed would be £260-280k although those prices obviously vary greatly with age and condition of the building.

I've filled out various building cost calculators which confirm my feeling that the build cost would be in the region of £160k if it was a good spec 'standard' build, but this obviously doesn't count the 'PassivHaus factor' which will undoubtedly add cost. Even the experienced PH designers (Justin Bere, Architype etc.) tend to suggest it's at least 8% extra on a standard build...

I agree. Calculate.. Finished Value - build cost - 20% and see how that compares with other plots. Don't forget to factor in the CIL/S106 and any special factors that might apply to that particular plot, such as high cost of getting services to it or moving underground cables/pipes ??

£15K ! I think you forgot a zero :-)

Edit: £15k for a site without planning permission?

Three years ago we sold my dad's former workshop unit for around £30k rather than go for PP and sell for houses.

The dimensions would have allowed three compact 3 bed terraces (plots roughly 9m wide x 20m deep each), but there was no value in building the houses as the sale price of the plots would have been only £10k each after clearance and PP.

In that street a reasonable 3 bed terrace is about £60k.

Ferdinand