Can some builders/experts review my extension and quote?

[Russinating]

We're having an extension, have approval from building control and now just need quotes and to commission a builder.

There's one builder who were originally in contact with last January to get a rough quote from. We've been in contact with him in the interim but have an accurate quote now and throughout we've liked him: comms, work, attitude, experience etc. However at this moment in time he's also the most expensive.

Another good thing is he's done a real proper breakdown and quote and I was hoping some builders or people that have had an extension before would have a quick scan and maybe point out any red flags or similar.

The quote is below:

For reference all the plans are below but I'll keep them as links so it doesn't get too image heavy.

Proposed ground floor: http://i.imgur.com/3MNDKOz.png
Proposed roof and rear elevation: http://i.imgur.com/RGNzn3w.png
Proposed section side: http://i.imgur.com/vzCftrJ.png
Proposed section rear: http://i.imgur.com/EbDIZ3F.png

Obviously as this is such a big job in terms of cost any and all advice is really greatly appreciated. I have sought other advice too, including from our architect, but am keen to get some completely independent and third party thoughts!

Thanks in advance.

 

[Maccapacca]

What's the range of quotes? How much cheaper is the cheapest? Have you completed a proper comparison.

There's loads of provisional sums that don't look enough, firm these up or have a pot of money set aside. Everything in section 6 looks far too little.

Breaking up at 50mm. Will probably be deeper so he'll come back for more money.

To me you could do with firming quite a bit up and either you or he taking the risk and appreciating the cost.

 

[DB_SamX]

Will have a look at your plans and the breakdown tomorrow (if I remember). Just about to go to bed.

 

[john_s]

There's loads of provisional sums that don't look enough, firm these up or have a pot of money set aside. Everything in section 6 looks far too little.

Breaking up at 50mm. Will probably be deeper so he'll come back for more money.

Those were the ones that stood out to me too.

 

[Russinating]

Thanks guys.

 

[DB_SamX]

I would also agree with the breaking up; doubt there's only 50mm there.

What is your contract arrangement; if the things listed end up costing more, does he take the hit, or do you, or share?

I would check that, also check and get timescales in writing, as well as agree now, what do do if bad weather stops work, who pays for delays, etc.

100mm hardcore seems way too little, especially if a ground bearing slab. I tend to specify minimum 150mm, but then I don't know what you are forming your floor on.

 

[the_r_sole]

Everything marked as provisional looks optimistic! Definitely get them firmed up - what has the architect said?
Allow a decent contingency if you are proceeding with provisionals like that

 

[BF-Bert]

Most expensive corridor I've seen.

 

[Jez]

Another element which sticks out to me is that £2200 on disposal and that first set of junk is a total waste of money in my opinion.

I just built an extension many times the size of that and the total spent for waste disposal was around £200.

Just get them to pile all the excavation stuff in a huge pile (soil and hardcore) somewhere where a grab loader can access it. A grab truck for soil and hardcore only is really cheap (£100ish for a huge load around here, i had 2 for a 500sq ft footprint). Anything else get them to make another pile and take it to the tip yourself afterwards, there wont be much.

You dont need to hire a WC and do you really need to put fencing up to the street? £315 for "Internal board protection", what is this? Some £15 OSB board nailed up?

 

[the_r_sole]

Another element which sticks out to me is that £2200 on disposal and that first set of junk is a total waste of money in my opinion.

I just built an extension many times the size of that and the total spent for waste disposal was around £200.

Just get them to pile all the excavation stuff in a huge pile (soil and hardcore) somewhere where a grab loader can access it. A grab truck for soil and hardcore only is really cheap (£100ish for a huge load around here, i had 2 for a 500sq ft footprint). Anything else get them to make another pile and take it to the tip yourself afterwards, there wont be much.

You dont need to hire a WC and do you really need to put fencing up to the street? £315 for "Internal board protection", what is this? Some £15 OSB board nailed up?

To be fair the new CDM regs are a pain for small contractors and they are now applicable to domestic scale jobs whether or not they are notifiable so staff welfare facilities need to be provided by a contractor in some form

 

[1mm3]

30k for a 1.5m single story corridor?

Or am I reading the images wrong?

 

[Jez]

To be fair the new CDM regs are a pain for small contractors and they are now applicable to domestic scale jobs whether or not they are notifiable so staff welfare facilities need to be provided by a contractor in some form

Just let them use your house toilet, we put some OSB down on the route to it and on the toilet floor. Nicer for them than an external portaloo as well Any other protection that they insist on surely take care of yourself, although it sounds bizarre that a builder would honestly care.

(And even after we did that the builders tended to just urinate on the site anyway )

Edit: Maybe my guys were easy going but i found as long as they had tea all day they really didnt care for much else, i chipped in with all the donkey work such as any protection and waste management etc.

 

[the_r_sole]

Just let them use your house toilet, we put some OSB down on the route to it and on the toilet floor. Nicer for them than an external portaloo as well

(And even after we did that the builders tended to just urinate on the site anyway )

True but some contractors won't do that if they have to secure the rest of the house and/alter the drainage... On a job like this you'd think it would be fine but I'm sure some contractors have been on cdm courses and getting scared into charging huge prelims! (Got a quote back recently with 80k in prelims for a site manager, WC and hot water supply!! Contractor wouldn't drop his price either because he had been advised it was all required)

 

[Jez]

True but some contractors won't do that if they have to secure the rest of the house and/alter the drainage... On a job like this you'd think it would be fine but I'm sure some contractors have been on cdm courses and getting scared into charging huge prelims! (Got a quote back recently with 80k in prelims for a site manager, WC and hot water supply!! Contractor wouldn't drop his price either because he had been advised it was all required)

Yeah i understand in the case of a large job...but this extension is absolutely tiny. Youd have thought that they could use an existing toilet.

There is definitely no need for skips on such a small job either. One grab load will have that taken care of.

 

[the_r_sole]

Yeah i understand in the case of a large job...but this extension is absolutely tiny. Youd have thought that they could use an existing toilet.

There is definitely no need for skips on such a small job either. One grab load will have that taken care of.

I've done many tiny jobs where the contractor still wants his own facilities as the house has been secured and they don't want to have to clean up a house!
Not needing a skip is completely dependent on where materials could be stored, might not be a nice accessible spot in reach of a machine so a skip is the easiest solution....

 

[Jez]

If that is the case then he can at least get a hardcore/soil only skip, they are far cheaper than £1475

All of the above might be entirely justified depending on circumstance which hasn't come across properly on a forum, but its worth him questioning every line in my opinion as on the face of it a lot looks to be a waste of money to me.

The costs easily run away from you when you have loads of lines at inflated values, just look at this, £30k for what looks like a corridor.

 

[Russinating]

Just to answer a few of the queries, we're a terraced house with no rear or side access and no front garden so the front door exits onto the pavement.

As per the quote the dig out will have to be by hand/handheld tools as there's no room or any way to get a digger in, and I'm guessing that the fencing is a H&S requirement because of that (they'll be moving across/on the pavement a fair amount).

No use of toilet either; we'll be living upstairs with our house cat in a makeshift flat which is the only part of the house that's been completed. There'll be a temporary door to stop the cat from escaping/dying and to try and keep dust downstairs as much as possible. Given the overall cost £27pw is worth them just having a portaloo!

However there is no need for the internal boarding. They only need to travel through one room which has a concrete floor and is pre-refurb as well so mess or damage isn't an issue.

The other quotes we've got are around the £25,000 mark but are no where near detailed, one just a figure the other just a list of stages but no idea if that includes WCs for example. Have another 3 builders over in the next 2 days so will see what they come back with too.

This builder knows he's the most expensive and I queried the cost. As below his response was quick and seems, well, certainly a lot more switched on than some tradesmen! My fear with even £20k quotes is it could get up to £30k once they've spec'd up the correct RSJs, veluxes, WCs etc etc.

I always try to cover and cost all aspects of a project, hence the extensive breakdown! This method, 95% of the time, means that there are no cost over-runs - unless it is for items such as; discovery of asbestos, additional requirements of the Building Inspector, unexploded armaments (!), etc. All items that are out of both our control.

We do, however, have provisional costings in for electrics and plumbing/heating. Obviously there are no details on the plans to cover this, so we can’t give a firm costing at this stage.

I am confident my quote is comprehensive and covers all aspects of the project. I suppose all you can do is analyse all the breakdowns together and satisfy yourselves that each will reach the desired end to the budget you have.

It’s not an easy task is it?

Still, I’m sure you’ll get a good job from whoever you go with, and, at the end of the day, your budget is your budget.

If you need any help along the way, just ask; I’m always available.

Payment terms would be:
1. No money upfront.
2. Fortnightly payments thereafter, following agreement of work completed/part completed as per the breakdown schedule.
3. Part completed work to be an agreed percentage of the total item cost eg '50% of internal plaster work completed'.
4. Invoice settlement no later than seven days from invoice date, unless by previous agreement.

Sorry if it sounds a bit formal, but hope this covers any fears you may have. I think the easiest way to look at it is, you won't pay anything for work that has not been done, only the works completed or part completed to an agreed amount.

 

[Jez]

The access through the house and over a pavement sounds like a nightmare to be fair.

Its worth knocking those skips off IMO, as well as the boarding which you have said you will query. Soil skips cost next to nothing in comparison with regular ones and wont come to much for that amount of spoil.

 

[Russinating]

There's two walls to be taken down, one of which is solid stone (albeit already has a window in it) and a (small) kitchen to be taken out as well. We've only hired one skip since we've been here and that was £280 for mixed. That part especially I'm not too worried about, I'll certainly ask him how many skips that covers and obviously if less are used I won't pay it, and if they are used then they'll be needed. It's the stuff that's unquantifiable (everything else) that I'm less sure about!

 

[Maccapacca]

Remember your comparing cost plus mark up. Your 280 skip will include 20% vat and he'll be marking up by at least 25% so your skips work out at 280 / 120 × 100 = 233 + 25% = 291. 1475 / 291 = 5 skips.

Are the skips on the road as they are more expensive. Will they need to be closed and locked? Skips are often filled yo by other people.