The True Cost of a Joinery Job: Labour, Materials, and Profit

Ask any joinery workshop owner their profit margin and you'll get one of two answers: a confident number based on guesswork, or an honest "I don't really know." The truth is, most workshops don't know the real profit on individual jobs because they can't accurately track the two biggest costs: labour and materials.

The Labour Problem

Materials are easy — you have invoices. But labour? Your joiner earned £700 this week and worked on three projects. How much of that £700 belongs to each project? Most workshops either ignore this question entirely or split it equally — both of which give you wrong numbers.

The accurate way is proportional allocation. If your joiner spent 3 days on Project A and 2 days on Project B, Project A gets 60% of his weekly wage and Project B gets 40%. Multiply this across all workers, all weeks, all projects, and you get the true labour cost per job. It's impossible to do by hand. It's trivial for software.

Materials: Quoted vs. Actual

You quoted 12 sheets of oak veneer MDF for a kitchen. Did you actually use 12? Or did two get damaged and you used 14? The difference between quoted materials and actual materials used is where profit margin evaporates. Tracking actual consumption — not just what you ordered — tells you the real material cost.

The Monthly Picture

Individual project profitability is important, but so is the monthly view. Total revenue (projects completed this month), total materials, total labour, overheads — and the real profit left over. This is the number that tells you if your business is healthy, and it's the number most workshops can only guess at.

Deposits and Cash Flow

Revenue isn't the same as cash in the bank. A £30,000 project with a 30% deposit means you've received £9,000 but you're spending £20,000 on materials and labour before the balance arrives. Tracking deposits, variations, and outstanding amounts per project is essential for cash flow management — the thing that actually kills businesses.

Using Data to Quote Better

The ultimate benefit of tracking costs on completed projects is improving future quotes. When you know that similar kitchens cost 35% in materials and 25% in labour, you can quote the next one with confidence instead of hope. Historical data turns quoting from art into science.