New Extension Build

[bennettp23]

Hi,

I'm having a 7.5 x 4m 30 m2 extension built. I'm going to project manage it myself and have a builder lined up at a day rate (with a labourer), he trusted guy who has done other work for me. Fully aware of the potential issues of paying a day rate vs job but I'm willing to take that risk. I also know a few tradesmen (sparky, kitchen fitter, plumber and plasterer) to do the rest so I'm hoping I can shop around and try to bring it in at a good cost.

I was looking for a 'sticky' of tips around thing like getting the best prices for material etc as I'll be buying it direct but haven't found anything.

In short:
Single story
4.5 meter knock through
new kitchen
pitched vaulted roof with 3 roof windows
3 leave bifolds
exterior doors
3 french windows

Plus any other tips about managing a build. Does anyone know any good guides or have some nuggets of wisdom (apart from get an overall price an leave them to it - which still does not guarantee a fixed price).

Thanks!

 

[Scarlet Pimpernel]

Take your plans to a Builders Marchant, so they can estimate quantities and ask them for an account for your build.
Ask around if you want. See what best discount you can get.

 

[noseall]

I'm going to project manage it myself ...... I'll be buying it direct

What I will say is be prepared for some materials shortages. Our BM are prioritising, or at least setting aside some of the critical items like cement, insulation, blocks etc, for the regulars.
Some BM's are suffering heavy goods driver shortages too, so deliveries may come with a long lead time.

Plan materials well in advance.

Make sure that the building sand you start with is in plentiful supply.

Make sure that the bricks you intend using are in stock.

Faffing about pinching pennies may cost you pounds in the long term, especially if you have trades standing around waiting for stuff. If materials are supplied haphazard, the trades will soon get peed off.

 

[bennettp23]

Thanks Noseall!

 

[cdbe]

There is no cheapest place for everything, but for most builders the convenience, reliability and service they get from their chosen merchant tends to outweigh this and they just pass the cost onto the customer. For you as the customer, every extra £50 here, £200 there or even £2 on a bag of cement x 50 bags is coming out of your pocket and there are potentially serious savings to be made but as Noseall says you have to be seriously "on it" as 3 blokes stood around/sweeping up for 2 days because you've bought the wrong lintels or 2 weeks because you forgot to order a scaffold will wipe out a lot of your work as will throwing a pack of thermalites in a skip because you forgot to deduct window and door openings when measuring up. Also remember that most merchants are business to business suppliers and won't let you keep returning things you've bought wrong like B&Q.

The other thing to do is have plenty of contingency work lined up, so for example if they have to drop off the brickwork have some drainage work available etc.

I'm doing a renovation/large extension on my house for virtually nothing, but my time is cheap (as I'm a sort of househusband) and it makes sense for me to do things like spend an hour on the phone to concrete suppliers to save £40, or make a 150 mile round trip to pick up a steel beam which cost me £125 on eBay as against £325 from my local steel stockholder.

A lot comes down to experience as well, for example is it cheaper to fill your foundation trenches with expensive concrete or pay your builders to build up from a strip foundation, do you buy or hire tools and plant? are your builders supplying them, are they going to get sick of answering all these questions and advising you when you're just paying them as day labourers? Who's managing compliance with building regulations, full plans or building notice, have you got/do you need a technician/structural engineer and do you know what you'll need him for; he may be happy to be paid to unnecessarily "design" every rafter and lintel for you or he may be worth his weight in gold and suggest a few simple changes that could save you a load of time and money.

I've found with my project that unless you're some kind of forensic accountant it's quite difficult to keep track of how much you've spent, especially when paying cash for various bits and pieces. I have a spreadsheet that's up to about £12K for mine but I haven't updated it for a while and my roof is eating money at the moment, not so much for the tiles and battens but all the extras - I have 2 valleys and 5 hips and am replacing all the fascias, leadwork etc - and woefully underestimated the cost of the materials for all of this - probably double the tiles and battens which you'd think are the main cost.

I wish you the best of luck, and if it does go a bit wrong, just treat it a a learning experience!

 

[^woody^]

I've seen that CLS has more than doubled in price since last year, and yet the timber industry association is saying that timber prices are only about 5% higher than three years ago

It's more than 300% in yankland

 

[bennettp23]

There is no cheapest place for everything, but for most builders the convenience, reliability and service they get from their chosen merchant tends to outweigh this and they just pass the cost onto the customer. For you as the customer, every extra £50 here, £200 there or even £2 on a bag of cement x 50 bags is coming out of your pocket and there are potentially serious savings to be made but as Noseall says you have to be seriously "on it" as 3 blokes stood around/sweeping up for 2 days because you've bought the wrong lintels or 2 weeks because you forgot to order a scaffold will wipe out a lot of your work as will throwing a pack of thermalites in a skip because you forgot to deduct window and door openings when measuring up. Also remember that most merchants are business to business suppliers and won't let you keep returning things you've bought wrong like B&Q.

The other thing to do is have plenty of contingency work lined up, so for example if they have to drop off the brickwork have some drainage work available etc.

I'm doing a renovation/large extension on my house for virtually nothing, but my time is cheap (as I'm a sort of househusband) and it makes sense for me to do things like spend an hour on the phone to concrete suppliers to save £40, or make a 150 mile round trip to pick up a steel beam which cost me £125 on eBay as against £325 from my local steel stockholder.

A lot comes down to experience as well, for example is it cheaper to fill your foundation trenches with expensive concrete or pay your builders to build up from a strip foundation, do you buy or hire tools and plant? are your builders supplying them, are they going to get sick of answering all these questions and advising you when you're just paying them as day labourers? Who's managing compliance with building regulations, full plans or building notice, have you got/do you need a technician/structural engineer and do you know what you'll need him for; he may be happy to be paid to unnecessarily "design" every rafter and lintel for you or he may be worth his weight in gold and suggest a few simple changes that could save you a load of time and money.

I've found with my project that unless you're some kind of forensic accountant it's quite difficult to keep track of how much you've spent, especially when paying cash for various bits and pieces. I have a spreadsheet that's up to about £12K for mine but I haven't updated it for a while and my roof is eating money at the moment, not so much for the tiles and battens but all the extras - I have 2 valleys and 5 hips and am replacing all the fascias, leadwork etc - and woefully underestimated the cost of the materials for all of this - probably double the tiles and battens which you'd think are the main cost.

I wish you the best of luck, and if it does go a bit wrong, just treat it a a learning experience!

Wow thanks so much for taking the time to write this. All makes sense.

I’ve got a lot of materials ahead of time e.g. roof tiles but I’m sure I’ll end up with wastage and changes of plans which will cost me. But I’m getting worried about supply so I’m willing to take that risk.

windows and doors appear to be another long lead time and I’m waiting for the brick work first course to be done for the openings to make sure it’s bang on - could cost me time.

Thanks again!