How to know how much materials to order?

[OldieNewbie]

How does a builder / contractor now how much material to order?

 

Do they use the drawings supplied by design team? Or would that be all on the bill of quantities? 
 

A side question- what is a bill of qualities. Where does it originate? Design Team? 

[JohnMo]

5 minutes ago, OldieNewbie said:

what is a bill of qualities

You pay a person to generate.

 

7 minutes ago, OldieNewbie said:

How does a builder / contractor now how much material to order

You can measure off the drawings calculate what you need, some will then add 10%, have loads of waste you pay for.

[OldieNewbie]

8 hours ago, JohnMo said:

You pay a person to generate.

 

You can measure off the drawings calculate what you need, some will then add 10%, have loads of waste you pay for.

Thanks. 
 

So a contractor gets the drawings for a job. 
He has two options;

 

A) He gets somebody to draw up a bill of quantities 

 

B) He measures the drawings him / her self and adds 10%. 

 

Would I be correct with that? 
 

Who would build use to produce a bill of quantities? 

[ETC]

9 hours ago, OldieNewbie said:

How does a builder / contractor now how much material to order?

He/she will either order off a Bill of Quantities produced by the client or will hire a QS to measure the quantity of material from drawings produced by the client.

 

Do they use the drawings supplied by design team? Or would that be all on the bill of quantities? 
Could be either - more than likely a BoQ.

 

A side question- what is a bill of qualities. Where does it originate? Design Team? 

A bill of quantities is basically a long shopping list of all the items (hopefully) needed to build a project mainly produced by the client’s design team.

 

Other options and procurement routes are available.

 

Edited February 10 by ETC

[Alan Ambrose]

>>> A) He gets somebody to draw up a bill of quantities 

 

e.g. a quantity surveyor i.e. QS. You can, of course buy in QS services quite cheaply. You send them the detailed drawings, the QS does their bit, and you get quantities and cost estimates.

 

>>> B) He measures the drawings him / her self and adds 10%. 
 

Hopefully a bit more subtle than that … depending on material / ability to source small top up quantities / fungibility (how similar materials with the same SKU actually are). e.g. for bricks & tiles you might want to slightly over order rather than risk a new batch with a subtly different shade.

[OldieNewbie]

4 hours ago, Alan Ambrose said:

 

>>> A) He gets somebody to draw up a bill of quantities 

 

e.g. a quantity surveyor i.e. QS. You can, of course buy in QS services quite cheaply. You send them the detailed drawings, the QS does their bit, and you get quantities and cost estimates.

 

>>> B) He measures the drawings him / her self and adds 10%. 
 

Hopefully a bit more subtle than that … depending on material / ability to source small top up quantities / fungibility (how similar materials with the same SKU actually are). e.g. for bricks & tiles you might want to slightly over order rather than risk a new batch with a subtly different shade.

Thank you. 

[OldieNewbie]

14 hours ago, ETC said:

 

Thanks ETC. Curious to know what the other routes of procurement may be? 

[ETC]

9 hours ago, OldieNewbie said:

Thanks ETC. Curious to know what the other routes of procurement may be? 

There are quite a few many of which wouldn’t be that suitable for a dwelling. The most notable would be design and build but there others like management contracting. The traditional procurement process which separates the design process from the construction process is the most common for run of the mill one-off housing.

[Gus Potter]

On 10/02/2025 at 11:39, OldieNewbie said:

How does a builder / contractor now how much material to order?

This is a bit long winded and a bit of a read! But I hope there plenty nuggets in here for the self builder to chew over. For the budding young person who wants to make a carear in the building trade.. I start with an introduction.

 

40 years ago I came out of college with an HND in Civil Engineering, went to work for Wimpey and got sacked because I was a prick.. I then went self employed and my first job was tiling a bathroom for a neighbour.

 

I worked out the cost of the material, my time and overheads. I then build a business in Edinburgh and employed a few folk. I met the girl of my dreams and we bought a plot in the Scottish Borders and did a self build. I employed an Architect that used to shove me a lot of work to do my design drawings. I got up every morning and built the house which took me three years now we expected and planned for that so we priced that in. Me working for free but no tax to pay.

 

We lived in the garage and a caravan. Looking back I'm very lucky to have been able to do that, few folk just don't get the chance although many are more than capable. We had no kids, a German Shepard and that was it.

 

To cost it I worked out how much materials I needed by measuring off the drawings and added on a percentage for waste (stock lengths of timber, lorry load deliveries of sand etc) and the mistakes I would make. About 10 -15%. I worked out how long it would take me to build the house, just by myself. I took me three years as above but I was young, fit and had my experience.

 

As I built the house, it was near a road, locals stopped and asked.. see when you finish Gus will you come and build our house. I did that and ended up being one of the biggest employers in the local area.

 

Now to price these jobs I still broke down all the material cost elements, I know how long each building task takes roughly so I can apportion a labour cost to that. I know what the business overheads are; running vans, sick pay, cost for apprentices and staff training, contractor insurance, plant replacement cost and so on are. I used a spread sheet to work all of that out and then apply a profit margin. Now a spread sheet can be a dangerous thing! A mistake could cost you your livelyhood (for self builder.. put you money at risk) and put your employees jobs at risk.

 

I used to do a second qualitative check to make sure I didn't loose my shirt and pants.. which was based on.. for a standard self build the labour cost should be about 1/3 of the base cost. In other words materials are about 2/3 of the cost. This is a good way of getting a good figure of labour material cost ratio as it tends to be inflation proof.. it's used as a qualitative check on the basic envelope and then you add in the big ticket items.. doors, heating etc. All the time you are looking at the different ways and methods of costing. Most are qualitative but even these give you a feel for what looks right and what is not.

 

Next was to look at the square metreage. At that time it was a lot less but say at the moment 2.0k a square metre. Do not use this value yourself, I've picked the number as it is easy but you can again do a check. This is the third check.

 

Now I was a building contractor and I wanted to make some money. Personally I don't gamble, don't but a lottery ticket. I still run a business as an SE / Designer and want to make a profit. The last bit that goes into the price is based on how much profit your want to make, for me now it's often about how interesting the job is and how you hit it off with the Client. I've picked up the odd job on Buildhub, the profit element is often very low but see the enjoyment I've got out of it working and learning from loads of you clever folk here!

 

Jumping forward a couple of decades or more I'm now an SE and Architectural designer. I still use the same rules and techniques when Clients ask me for a budget cost. In some ways because of my background I'm actually doing what a professional Quantity Surveyor (QS) does but in a rough way.

 

Some of the builders I work with use a QS to price all their jobs.. but that comes at a cost. Others adopt old school pricing methods coupled with modern techniques like I do.

 

Some small builders go on the internet and look up what the internet says and add 20 -60% or just double it.. if they get the job then they know there is so much profit there they can afford to figure out how to do it once they have collected your deposit.

 

In terms of pricing self builds, professional fees and contracts.

 

Often I get asked by Clients what kind of contract they need. Now my opening gambit is that you should have an industry recognised contract that it tailored to what you want to do. Could be a minor works, JCT or NEC type. But all these need some element of extra professional input that comes at a cost and that cost can at times be 80% of the original design fee, do you know how much a Clerk of works costs!

 

Simplistically if you want me to do this then I am responsible for your money and authorising payment on your behalf.  If I cock up you have a perfectly clear run to to sue me for your losses. To be clear If I authorise a payment to the Contractor you have to pretty much cough up like it or not!

 

Now this is a Self Build site. Most folk do their own deal with a builder. For many it works out well, there are a few casualties but that is the risk you run folks.

 

I'll stop here but Build Hub is a great place to learn. I learn all the time!

 

 

 

 

 

 

 

Edited February 11 by Gus Potter

[saveasteading]

I was an estimator for years. As a contractor you have to get it dead right or you lose the job or lose money. Waste is not acceptable.OR accept iinevitable table and allow for it.

A bill of quantities by another party is a start but can be too generic....or have errors.

 

In it's simplest terms a builder looks at the work and either 'feels' how long a job will take, or calculates by other means, or a combination. 

Some aspects are well documented. How many bricks per m2? How much sand and cement, and so on.

 

It is all highly skilled. Sometimes it is a gamble.

 

Waste is discussed above. A bricklayer supplying the materials will have negligible waste.  Free supply and they won't use a bent one, pick up a dropped one or save half bricks for the next use.....and then they fill the skip.

 

 

It's a huge subject so needs to be more specific if there remain questions.