Extension 4m square cost

Bleg

We need a 4m square extension. I am struggling to get quotations from builders. I call, .....then.... some get back to me......... fewer still actually turn up....... and actually getting a quotation out of them is something else.  Its very frustating.  Can anyone out there who has had similar work done in  the past share what I can roughly expect to pay. Its an extension to the kitchen to provide an eating area. Its more or less a 4msquared box with a pitched roof and a velux window.

We are in the Northwest Kent area. I would just like a rough idea so that when I do eventually get a quotation with someone I could work with I would be able to judge it fairly.

TELLIT01

The sort of figure I see mentioned is £2.5k to £3k per square metre.  That is for a dry shell.  Fitting out would be more.

grumpy_codger

TELLIT01 said:

The sort of figure I see mentioned is £2.5k to £3k per square metre.  That is for a dry shell.  Fitting out would be more.

It's worth saying that generally for a small area you should expect the figure per square meter to be bigger because the wall length per square meter is bigger. It's pure geometry. 

E.g,  40m2 area is 10 times as big as 4m2 while the (three) walls are 19m vs 6m, i.e. just about 3 times as long (10^0.5)

 

TELLIT01

@grumpy_codger that's fair comment, but the figure I have given has been mentioned in the past for a single storey extension.

stuart45

Timewise, it's not much quicker to build a short wall than a longer wall. Most of the time spent is on the corners. Running an extra 10 bricks in to the line doesn't take long.

Section62

stuart45 said:

Timewise, it's not much quicker to build a short wall than a longer wall. Most of the time spent is on the corners. Running an extra 10 bricks in to the line doesn't take long.

Yes, I'd say a more significant factor on cost/m^2 for rear extensions is access... a significant difference between digging footings by hand or machine, and whether everything has to be manually carried through the house, or can be barrowed along a (level) outside path/drive.  Increasingly in urban areas skip space and ability to park somewhere near the job are important too.

OP, from your words "I would just like a rough idea so that when I do eventually get a quotation with someone I could work with I would be able to judge it fairly" I'd guess you are giving the impression you aren't looking for a quote for a job to start anytime soon, but instead come across as someone wanting a ballpark figure for planning purposes.  Builders are busy, so won't spend much time providing quotes/estimates for jobs that may never happen, or if they sense the client has no intention of giving them the work.

Do you have any drawings yet?

Bleg

I am ready to go. i have all the plans. Access is not a problem. Parking is not a problem. builders responding IS the problem.  I would like a rough figure from this forum just so I would know what others are paying so when the quotations start coming in I would have a fair idea.

Section62

Bleg said:

I am ready to go. i have all the plans. Access is not a problem. Parking is not a problem. builders responding IS the problem.  I would like a rough figure from this forum just so I would know what others are paying so when the quotations start coming in I would have a fair idea.

Just wait until you get the quotes then - if they are all around the same figure you'll know what a reasonable figure looks like.  If one is much cheaper (say 10%) than the next lowest then exercise caution before accepting it.

This forum is better at dealing with questions like "Why is this quote 10% cheaper than all the others?" rather than guessing what someone's build cost is going to be.

jonnydeppiwish!

In all honesty, you’re probably looking at £20-£25k depending where you are based.  

casper_gutman

Is the extension going to be...
4 square metres, so 2m × 2m = 4m², or
4 metres square, so 4m × 4m = 16m² ?

Bleg

4mX4m ie 16m square. single story with pitched roof excluding doors and windows.