Extension Help/Quote

[Candyman21]

Hi Guys,

I know this is a how long is a piece of string question, but any rough estimates will be fine Below is a picture of the back of my house, i am thinking about having an extension built, this would mean knocking the outbuilding down as its single skin, the room to the left is a kitchen/diner. I would be hoping the bottom part of the extension would be an extended kitchen, this would need an RSJ putting in so i could take out the existing external wall to open the space up, the 2nd floor would be an additional bedroom. I would ideally like the extension to be the full height of the house and the top could form a possible small bathroom for when i have a future loft conversion.

Ball park figure what would i be looking at for something like this? I know this is a really subjective question but any input would be greatly appreciated.

Any other suggestions for another layout would also be appreciated, some people have mentioned a wrap around extension, the extension cant really be much bigger than the current outbuilding as the front space is at a funny angle.

Thanks

John

 

[Notch7]

Whatever it costs, add £10k if your missus is involved in the 'interior design'

Cost....no idea, more than £50k less than £100k for 2storey jobbie would be my rolling the dice guestimate.

The cheapest easiest way would be get a builder to do founds, walls, roof, knockthrough, maybe electrics, plumbing, screeding plastering. You organise interior stuff like tiling, decorating, 2nd fix carpentry etc.

 

[Candyman21]

Whatever it costs, add £10k is your missus is involved in the 'interior design'

Cost....no idea, more than £50k less than £100k for 2storey jobbie would be my rolling the dice guestimate.

The cheapest easiest way would be get a builder to do founds, walls, roof, knockthrough, maybe electrics, plumbing, screeding plastering. You organise interior stuff like tiling, decorating, 2nd fix carpentry etc.

Haha, probably 15k on interior for my Mrs! Although i do like shopping around for bargains I could get the electrics/plumbing and plastering sorted as i know people in them trades.

Would you save much money by project managing it yourself and hiring all the relevant trade people separately? I think i would enjoy the sourcing of materials and trying to save money that way.

Thank you for the reply.

 

[Notch7]

Would you save much money by project managing it yourself and hiring all the relevant trade people separately? I think i would enjoy the sourcing of materials and trying to save money that way

That depends. If you linked to construction and have lots of contacts......yes

If you dont have contacts and little knowledge.......you might get lucky and save a bit or you could catch a cold by doing something wrong and cost a lot more.
Professional builders, have contacts, they have regular subbies that are tried and tested and because the use them regularly they can get them when they need them and the different subbies will all liaise and work together.

If you have a busy job with limited time, dont project manage, you will be shocked by the amount of effort required.

Your simplist way, would be to get a builder to do the shell; founds, walls, roof. Easy for a builder to quote, a nice quick job that he can turn around nice and quickly. Then you could do all your own subbie trades in your own time.

 

[pilsbury]

Getting the shell done might be a job builders want more than a full finished extension. Someone mentioned a good while ago to me that it’s the finish that ends up with the big snagging list. A PITA for them when money is with held and the job runs over.

 

[acurachris]

If you have a busy job with limited time, dont project manage, you will be shocked by the amount of effort required.

I am doing exactly this and i agree with you 100%, i'm stressed to my eyeballs . It's a rollercoaster of enjoyment and disappointment and it's taking an age!

On the flip side, i've learned a lot about the process and although i've not known any trades, i've spoken to loads over the last few months and found a groundwork and a pile contractor who have been really helpful.

I suppose it's hard work (more than anyone thinks initially, as Notch7 says) but IF you can (and me!) get the house finished with your own project managing, it's going to be worthwhile.

 

[Candyman21]

Getting the shell done might be a job builders want more than a full finished extension. Someone mentioned a good while ago to me that it’s the finish that ends up with the big snagging list. A PITA for them when money is with held and the job runs over.

How much money could you potentially save by getting the builders to build just the shell for you?

 

[acurachris]

How much money could you potentially save by getting the builders to build just the shell for you?

You are doing a similar extension to me. I had to knock down a single storey side extension and want to put up two storey side + small single on side of that. I asked five builders to quote. Two quoted (can't remember exactly, but...). One builder quoted about £79,000 built and finished to plaster or £65,000 if just brick finish. The other guy quoted about £63,000 to plaster finish or about £45,000 to brick finish (he was cheaper as he said "no vat" ). These quotes were based on standard trench/strip foundations too.

I got the impression they didn't want to do just the shell (which is what i wanted, cause i can do the interior fit myself), but maybe that was the builders i had out. I also thought it was a lot of money although it's about right on average. Labour is the biggest cost as i'm sure you know. Of the two quotes, one broke the materials and labour down into separate prices the other quote was a price which didn't really show what cost what.

 

[acurachris]

I've just found one of the quotes actually. The N/A vat guy . £62,049 + £3102 contingency. He broke the labour down to be £31,940.

 

[Candyman21]

Would it be worth digging the foundations and getting the concrete poured, then hiring a bricklayer to start the brickwork before getting a builder to look at putting the RSJ's in? Obviously after all the plans have been submitted and signed off!

 

[Diver Fred]

Would it be worth digging the foundations and getting the concrete poured, then hiring a bricklayer to start the brickwork before getting a builder to look at putting the RSJ's in? Obviously after all the plans have been submitted and signed off!

one word answer - NO!

My best suggestion is consult an architec - one who knows the area and local authority. Commision him to draw up the plans and send to the LA. At the same time he should know suitable builders and be able to guide you on what you want to do; a really good one will also PM or guide you through that.

 

[Notch7]

Would it be worth digging the foundations and getting the concrete poured, then hiring a bricklayer to start the brickwork before getting a builder to look at putting the RSJ's in? Obviously after all the plans have been submitted and signed off!

Get the foundation done and brickwork / blockwork up enough to concrete oversite -which gives a flat floor to move a genie lift about.

It may be best to get the steels i before going further as the brickwork might make moving the steels around awkward. Dont forget the steels can go in and leave the brickwork below whcih can be knocked out later on.