Somewhere between £95 and £150 per square foot dependent on MANY variables
was what I was told.
It would be interesting to do a survey on the group of people who have had
extensions & new builds done and work out if these figures still hold.
On Mon, 9 Feb 2004 07:57:33 +0000 (UTC), Andrew Mawson wrote:
I have long held the view that when you arrive at a budget cost -
including every possible thing and contingency you can think of -
double it and you'll get a figure approaching the true cost of doing the
My SiL did something similar, but more extensive.
Will also need piers to support the RSJ, which will
eat into the width of the garage; as would having a
cavity wall at the side to support the second floor.
Scaffolding for building the higher wall right on the
boundary might be interesting as well.
I'm in north Derbyshire. We are having an extension to our existing 2
bedroomed semi. We are building an integral garage, utility room,
sunroom downstairs, with 2 bedrooms and new bathroom upstairs. The
upper floor will be about 8m long by 3.5m wide and downstairs 10m x
Three estimates from FMB registered builders (1 recommended by the
architect, and 2 from the yelow pages) all came in at about 43,000
(inc VAT), give or take a couple of hundred punds either way. No wild
variations, which came as a relief!
However, as the builder whol got the job (based on personal intutition
really) said to me, the true cost will be about 25% higher, as
specifications change. For example he's put in a PC sum of about £500
for fitting the new bathroom, whereas this would only buy a tap in my
my wife's ideas for the bathroom!
Anyway, hope this helps.
we had estimates for around £25000 to do two floors and about £15000 for
just the one floor.
all this included was the built structure, and just the first fix door
casings and windows to make it weatherproof. no electrics, no plumbing, no
You really need the drawings to get proper estimates. You may even have to
have the front top floor recessed, so as not to make the house look
terraced, and to have room for two off road parking spaces.
scaffolding is not a problem, they can work from inside moving up.
boundaries can be a problem but with the new legislation, you can build
right up to the edge and build footings on your neighbours side without his
permission. This is to prevent the stupid 6" gaps appearing between
extensions. He can object and appeal, but will be stopped from interfering
if you are granted permission.
we are in the north west by the way, semis go for about £170,000 here.
just recently had the extension to the rear. single story. cost about £15000
in total, it was made more expensive due to the internal ceiling following
the roof line and two large velux windows being installed.
great job though, did electrics and plumbing, painting, woodwork myself,
but total overall was £15000.
hope this helps
Useful info. Sounds like you have gone down a similar path. What size
is your extension by the way?
Some houses in the street have garages built side by side without gap
and with a continuous roof over them, they look far better. Do you know
what the situation is when one person builds up to the boundary and the
foundations extend over it, then the other person wants to build up to
it without gap? Does the second person build on the foundations that
extend onto his side? If so, what happens if those foundations are only
suitable for a single story garage and the second person wants to build
The reason I am asking is that the neighbouring house has a garage built
up to the boundary, possibly by the original builders by the match of
the brickwork. That may complicate things.
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