How to price a job

How to price a job and bill of quantities

The pricing example in this lesson relates to the foundation and ground floor construction takeoff. Follow the link if you still need to read the lesson.

Before we can price a job and bill of quantities, we need to obtain labour, plant, and materials costs for the foundation and ground floor construction.

Labour

  • Labourer £15 per hour £120 per day
  • Bricklayer £22 per hour £176 per day
  • Plant driver per hour £150 per day
  • Bricklayer rate for facing brick – £1,000/1000
  • Bricklayer rate for common brick – £750/1000
  • Bricklayer rate for blockwork – £20m2

Plant

  • 5-ton mini excavator £150 per day
  • 16-ton grab wagon £375 per trip

Materials

  • C15 concrete £145 m3
  • C20 concrete £150 m3
  • Concrete commos £350/1000
  • Facing bricks £750/1000
  • Tub of mortar 250 litre £75 per tub
  • Brick ties £12 for a box of 50
  • 140mm dense concrete 7/n blocks £20 m2
  • MOT type 1 stone £29 ton
  • Visqueen 1000g DPM 4m x 25m £60 per roll

Pricing a job and built up rates

I will show you how to price the main items within the bill of quantities.

Excavations

The productivity of a 5-ton mini excavator is 3m3 per hour

The total quantity of excavations is 29m3; therefore, 29/3 = 10 productive work hours. We will allow for two days of work, which will allow setting up and delivering the plant.

2 days of mini excavator @ £150 day = £300

Delivery and removal of the excavator £50 each way = £100

2 days driver @ £168 = £326

Total cost £726 / 29 m3 = £25.03 m3

The £25 m3 rate can be put into the plant section of the bill of quantities. £25 is divided by 6.66 to give the rate of £3.75 for 150mm of reduced excavation to remove the topsoil. 

The rate of £25 per m3 is expensive. On bulk excavations of 1000m3, this rate can be reduced using a larger excavation plant. The rate is high due to the small quantity.

Level and ram is a risk item – Just add some cost to cover cleaning out the trench

Earthwork support is a risk item = Just add cost to cover material falling into the trench and extra material to fill the void.

Disposal

The 16-ton wagon can remove 10m3 of material per load. We have two loads. The cost = 2 x £375 = £750

£750/20 m3 = £37.5 per m3

Concrete

We add 10% waste to the cost of the concrete.

I have included two men half a day to pour the concrete.

Masonry

It is normal to pay a bricklayer per 1000 bricks. The current rate for facing brickwork is £750/£1000 per 1000. We will allow for the top end. If you can buy better during the operation, you will save money.

The labour calculation is £1000/1000 = £1 per brick x 60 bricks in a m2 the rate = £60 m2.

The facing bricks are £750 per 1000 delivered. £750/1000 = £0.75 per brick x 60 bricks in a m2 = £45

A tub of mortar is £75, and 1 tub will build 12.5m2 of brickwork. The rate for mortar is £75/12.5 = £6 m2

£45 + £6 = £51 + 5% waste the rate = £53.55

Masonry rate for laying common brick 750/1000

Common bricks are £350/1000

The rate for labour £45 m2The rate for the material £28.35

Blockwork

Labour £20 m2

Material £20 m2 plus £3 for mortar plus 5% waste = 24.15

Wall ties £12/50 = x 5 per m2 + 5% waste = £1.26

Fillings

Stone £29 per ton x 1.6 to convert into m3 = £46.4 plus 10% waste = £51.04 (1.6 is the mass of stone per m3)

I have allowed two men 155 days

Earthwork compaction 

2 hours to compact and a sum to cover the cost to hire a vibrating plate

Concrete to floor slab and cavity fill

We have a rate for the concrete, I have allowed to fill the cavity at the same time as the slab using the same material. Using C15 to cavity wall would be too expensive for 2 m3. Better using a full load for both concrete items

The surface finish to the concrete is to cover the cost of tamping and troweling

I added 20% waste to the Visqueen due to the small amount.

Gross-priced bill of quantities.

The bill of quantities above is gross, meaning an overhead and profit margin has been added. See the yellow box with 15% in it.

The bill of quantities will be gross when priced for a contractor.

The overhead is calculated by dividing the head office overhead of the contractor by the annual turnover. A contractor with overheads of £500,000 and a turnover of £5,000,000 requires a 10% margin to earn the overhead value. £500,000/£5,000,000 x 100 =10%

A contractor will add 2.5% to 10% for profit. The amount depends on the contractor’s size, the return they are looking for, and the risk.

10% + 5% = 15% added into the margin box.

One reason to obtain a few contractor prices is that each contractor will have a different overhead and margin to add to their calculated costs.

Nett-priced bill of quantities.

The nett priced bill of quantities has no overheads and profit added. A contractor will use this version to manage the project and try to buy better than the budget to make more profit.

A homeowner may wish to project manage the construction of their building. In this case, you can use the nett bill of quantities, and again, the aim is to buy better than the budget.

Spons price book

If you look up the rates for excavation, for example, you will see the rates are:

  • Excavation topsoil 150 thick  £1.22 m2
  • Excavation to reduce level max thickness 250mm £1.27m3
  • Excavation trench not exceeding 1m deep £8.26

Spons rates are used to price a job on large projects, The reduce excavation rates use bull dozers for example to move earth.

You can see the rates are a long way off what we calculated. 

More estimating lessons

A very simple set of estimating lessons to get you started. Everything you need to know to take off quantities, then pricing them. The lessons are short and to the point. I hope you find them useful.

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