Updating rates in a bill of quantities means more than changing figures in a column. You decide which rates are stale, move them to a current base using a published index or fresh quotes, test the result against the project, and record why each change was made. This guide sets out that process for UK quantity surveyors, with the current market context as of October 2026.
TL;DR
- Separate the three jobs: indexing old rates forward, replacing them with fresh quotes, and building up rates for risky items.
- Use a construction-specific index such as the BCIS tender price and building cost indices, not CPI, to move rates between dates.
- Check preliminaries, overheads and profit after every rate change, because they move with duration and method of working.
- Record the source, date and reason for every changed rate so the priced BoQ can be defended at tender review.
- Treat any automated or library rate as a starting point that a QS tests and signs off.
Table of Contents
- What updating rates in a BoQ really involves
- Know the market before you touch a rate
- Choose the right index, and not CPI
- A step-by-step method for updating a BoQ
- Do not forget preliminaries
- Labour rates and regional variation
- Keep an audit trail for every changed rate
- Build a rate library you can trust
- Common mistakes when updating BoQ rates
- Where drawing-based software fits
- FAQ
- Sources
What updating rates in a BoQ really involves
A priced bill of quantities is a set of measured items, each with a rate. Rates age quickly, and not at the same speed. Steel, copper and oil-derived products move differently from brickwork, and labour moves differently again. A single blanket uplift applied to the whole bill hides all of that.
Under RICS NRM 2, the bill invites contractors to show how they intend to work and which resources they will commit. That matters for rate updates. When you change a rate, you are changing a statement about how the work will be done and paid for, not only a number. The measurement rules themselves, including NRM 1 and NRM 3 alongside NRM 2, are listed on the RICS NRM page.
The job usually falls into one of three situations:
| Situation | Typical trigger | Usual method |
|---|---|---|
| Re-basing an old priced BoQ | Reusing a past tender or a cost plan for a new project | Index rates from the old base date to the new one, then spot-check |
| Refreshing a rate library | Quarterly or annual maintenance | Update by trade or element using indices and recent quotes |
| Repricing during tender | Addenda, late quotes, a volatile material | Replace individual rates with current subcontractor or supplier prices |
Knowing which of these you are doing decides how much evidence you need.
Know the market before you touch a rate
The direction of the market tells you how aggressive an update should be, and where it can safely be conservative.
The BCIS All-in Tender Price Index showed annual growth of 3.2% in the third quarter of 2026, based on an estimated rise of 0.7% between 2Q2026 and 3Q2026. The same BCIS release reports annual growth of 4.3% in the General Building Cost Index. BCIS forecasts tender price growth of 3.0% in 4Q2026.
That gap between 4.3% and 3.2% is the point. Input costs are rising faster than the prices contractors are able to charge. The Autumn 2026 Tender Price Indicator sets UK tender price inflation at 3.25% for 2026, down from 3.50%, and reports that 51% of its survey respondents see upside risk to their own forecasts, while weaker demand curbs pricing power.
For a QS, this has two practical consequences:
- Pricing for a contractor: a rate built purely from current costs may be uncompetitive, while a rate that ignores cost pressure may erode margin.
- Pricing for a client: an estimate indexed only by tender prices may understate what contractors will ask for on volatile packages.
Neither is a reason to apply a single percentage. It is a reason to know which rates in the bill are cost-sensitive.
Choose the right index, and not CPI
Headline inflation is a poor guide to construction pricing. BCIS senior economist Sam Parkin makes the point in its construction materials prices briefing: general indices such as CPI tend to lag sector-specific inflation, and BCIS points practitioners to its Price Adjustment Formulae Indices for tracking specific materials.
The same page notes that each month the Department for Business and Trade publishes construction materials price indices, split into categories including All Work, New Housing, Other New Work and Repair and Maintenance, alongside selected individual building materials. These are a sensible check on material-heavy rates.
A working rule of thumb for choosing an index:
- Tender price index when you are updating a price the client would pay, such as a cost plan or a past tender sum.
- Building cost index when you are updating what it costs the contractor to build, such as a cost-based rate build-up.
- Materials price indices when a single material dominates the rate, such as reinforcement steel, copper pipework or insulation.
- Fresh quotes whenever an item is large, unusual or exposed to a volatile input.
Indices are averages across the country and across building types. They tell you the direction and rough scale of movement. They do not tell you what your local groundworker will quote next Tuesday.
A step-by-step method for updating a BoQ
1. Freeze the quantities first
Rate updates and quantity changes are separate exercises. If quantities are still moving because of a drawing revision, finish that first or log the two sets of changes separately. Mixing them makes it impossible to explain a movement in the total. If addenda are arriving during tender, the seven-step triage for tender addendum quantities covers how to keep the two apart.
2. Identify the base date of every rate
Every rate in the bill should carry a date and a source. If it does not, assume it is old and mark it for review. Group rates by base date, because a bill built from a mixture of 2023, 2024 and 2026 rates needs different adjustments for each group.
3. Rank items by value and volatility
Sort the priced bill by value. In most bills a modest number of items carry most of the money. Spend your time there. Then flag items exposed to volatile inputs, such as steel, copper, insulation and anything oil-derived.
4. Index the low-risk majority
For routine, low-value items with stable prices, apply a published index between the rate's base date and today, by trade or element where the data allows. Record the index used, the two dates and the factor applied.
5. Replace the high-value and high-risk rates
For the items that matter, go back to the market: supplier quotes, subcontractor quotes, or a proper rate build-up. The choice between a library rate and a built-up rate is covered in Rate Build Up vs Library Rates, which looks at how UK QSs price risky BoQ items.
6. Re-test preliminaries, overheads and profit
This is the step most often skipped, and it gets its own section below.
7. Sense-check against benchmarks
Compare the updated total, and key elemental costs, against benchmark data. Cost per square metre by element is the usual test. If your updated figure sits well outside the range of comparable projects, find out why before it goes out. Methods for this are set out in the 2026 guide to construction cost benchmarking.
8. Record, review and sign off
Write down what changed and why. A second pair of eyes on the high-value items catches the transposed decimal and the unit mismatch that no index will.
Do not forget preliminaries
A rate change can alter duration, plant needs or site management, and when it does, the preliminaries should follow. If a material now has a longer lead time, or a trade package is only available at a later start date, the programme changes, and time-related preliminaries change with it.
The RICS guidance describes the bill as the place where contractors set out their method of working and resource allocation. A priced bill whose rates have been updated but whose preliminaries still reflect the old programme is internally inconsistent. Reviewers at tender stage look for exactly that.
A short checklist after any significant rate change:
- Has the programme duration changed, even by a few weeks?
- Do time-related items (site management, welfare, scaffold hire, plant) still match the programme?
- Have overheads and profit been applied on the new totals rather than on the old ones?
- Is any risk allowance now double-counted, because a volatile rate already includes a contingency?
On the last point, be explicit. If you have built contingency into a rate for a volatile material, say so in the build-up and do not add a second allowance elsewhere for the same exposure.
Labour rates and regional variation
Labour is the part of a rate that indices capture least well, because it depends on where the site is and which trades are available. Published figures give a sense of the spread. A builder pricing guide, last updated in April 2025, reports general builder day rates of roughly £175 to £210, with London reaching up to £250 and some regions as low as £148 to £160. That source is aimed at homeowners and is a rough guide to the spread, not a substitute for trade-package quotes on a commercial or multi-unit job, but it shows why a single national labour assumption is risky.
Where your project sits in the country matters, and so does what else is being built nearby. Specialist labour shortages push up specific trades faster than the average. If a package is thin on bidders, a quote beats an index every time.
People working in other markets often face the same issue with different mechanics. A contracting guide written for Gulf-region building projects shows how contract structure and cost allocation are handled there, which is a useful contrast when you are thinking about how much price risk a rate should carry under a UK form of contract.
Keep an audit trail for every changed rate
If a client, a contractor or a colleague asks why a rate changed, you should be able to answer in one line. A simple log needs five fields:
- The BoQ item reference and description
- The old rate and its base date
- The new rate and the date it applies
- The source: index name and period, quote reference, or build-up
- The person who made and approved the change
The same discipline applies to quantities. When a drawing revision changes a measurement, the BoQ line should be traceable to the revision that caused it, which is the approach described in linking each BoQ line to its drawing revision. Rates and quantities together make the price, so both need a trail.
Build a rate library you can trust
Repeated updating gets easier when your starting rates are organised. A custom library, structured to follow NRM 2 work sections, lets you update by section rather than line by line. The approach is described in building an NRM 2 aligned custom rate library for UK SME QS teams.
Some principles that keep a library useful:
- Date-stamp every rate and show its source.
- Separate labour, plant and materials where you can, so each can be indexed independently.
- Set a review cycle, quarterly for volatile items and annually for the rest.
- Retire rates that have not been used or tested for a long time, rather than letting them linger as false comfort.
- Note the conditions attached to a rate: location, access, quantity thresholds, and whether it includes overheads and profit.
For wider guidance on how pricing fits into the whole bill, see the practical guide to BoQ pricing for UK quantity surveyors.
Common mistakes when updating BoQ rates
Applying one percentage to everything. Different trades and materials move differently. Index by trade or element at the least.
Using CPI. It lags construction-specific movement, as the BCIS commentary above explains.
Trusting library rates blindly. Relying solely on historical rate databases without adjusting for recent material inflation or local trade availability creates tender risk. A library rate is a starting point that you test.
Leaving preliminaries untouched. Covered above, and the most common source of internal inconsistency.
Updating rates and quantities in the same pass. You lose the ability to explain what moved the total.
Forgetting the market gap. With building costs rising faster than tender prices, pricing purely from cost can lose work, and pricing purely from tender indices can leave margin thin. Decide deliberately which you are doing.
Not recording the basis. A rate with no source cannot be defended.
Where drawing-based software fits
Speeding up the measurement side leaves more time for the pricing judgement above. We are developing QuantiFlow to read construction drawings and produce a draft bill of quantities for a quantity surveyor to review and sign off. The rate decisions described in this article stay with you. If you want to follow its progress, see the QuantiFlow site. For a wider view of the category, the guide to quantity takeoff software for UK QS firms explains what to look for.
FAQ
How often should I update the rates in a BoQ?
Update before every tender or cost plan issue, and review your library on a fixed cycle. Quarterly suits volatile materials and trades, and annually is usually enough for stable items. BCIS publishes its tender price estimate each quarter, which makes quarterly a natural rhythm.
Can I use CPI to uplift old BoQ rates?
It is not advisable. BCIS economists note that CPI lags sector-specific construction inflation. Use a tender price index, a building cost index or materials price indices, and confirm high-value items with quotes.
Do I need to change preliminaries when I update rates?
Often, yes. If the change alters the programme, plant or site management needs, the time-related preliminaries should change too. Check overheads and profit are calculated on the revised totals as well.
What is the difference between a tender price index and a building cost index?
A tender price index tracks what clients pay contractors, so it reflects competition and margins. A building cost index tracks the cost of inputs such as labour and materials. In Q3 2026 BCIS reported annual growth of 3.2% for the first and 4.3% for the second, so the choice changes the answer.
Sources
- BCIS Tender Price Index estimate of tender price inflation
- BCIS latest construction materials prices
- Tender Price Indicator, Autumn 2026
- RICS New rules of measurement (NRM 2)
- RICS NRM: New Rules of Measurement
- Builder Prices: how much do builders charge in the UK
Recommended
- Rate Build Up vs Library Rates: How UK QSs Price Risky BoQ Items
- BoQ pricing for UK quantity surveyors: practical guide
- Provisional sums in BoQ: a practical guide for QSs
- Seven BoQ Review Steps for UK QSs, Tied to Standards and Contracts
This article is for general information only and is not professional, legal or commercial advice. Quantity surveying decisions should be taken by a qualified professional with reference to the specific project, drawings and contract in question. Content is produced with AI assistance and reviewed before publication. QuantiFlow Ltd accepts no liability for reliance on it.