Builder’s quote, cost plan or Schedule of Works: which do you need and when?

“Why would I pay for a cost plan when a builder can give me a quote?”

It is a reasonable question, and one I hear from homeowners.

The answer starts with what you need to decide. Are you working out what you can afford, choosing between designs, or ready to appoint someone to build? A builder’s quote, a cost plan and a Schedule of Works help with different parts of that process.

For plain-English explanations of the terms you will encounter along the way, use our construction terms glossary.

Builder’s quote, cost plan or Schedule of Works: the differences

A builder’s quote sets out what that builder proposes to charge for the work described, subject to their stated scope, assumptions and terms. You need to understand those details before appointing them. A rough figure given during an early conversation is not the same as a price based on a developed package of information.

A design cost check (Elemental Cost Plan) is an independent estimate of what your design is likely to cost. It breaks the work into building elements so you and your designer can see where the money goes, compare options and test the design against your budget. It should also make reasonable allowances for incomplete design and identified risks, with the likely cost of completing the project in view.

A builder pricing pack (Schedule of Works) gives builders a common, detailed list of work to price alongside the drawings and specification. It helps you compare their submissions and spot omissions, allowances and qualifications. It does not, by itself, tell you what every item should cost.

These documents can work together. The level of detail and support should suit your project, rather than every homeowner being sold the same package.

See the difference in the documents

These short extracts show the distinction in practice. They come from different sample projects, so the quantities and work should not be compared as if they describe the same job. The ECP uses historical costs to illustrate the format.

A cost plan contains estimated costs

The QS has entered estimated rates and totals for the work. This gives you and your designer a basis for discussing the likely cost and the effect of changing the design.

Cost plan example: selected foundation and floor items from a refurbishment and extension project. View the cost plan extract at full size.

A Schedule of Works asks builders to price the work

The descriptions and quantities are set out, with rate and value columns for each builder to complete. The priced return then gives you a more consistent basis for comparing their offers.

Schedule of Works example: four demolition and alteration items, reformatted from the sample Excel file. View the Schedule of Works extract at full size.

See more examples in our guides to cost plans for new-build and renovation projects and Schedules of Works for builders’ quotes.

What about the free builder’s quote?

A builder may offer a quote without a separate charge. Detailed estimating or pre-construction work may be chargeable, so check what is included before asking them to proceed.

There are good builders who give useful, honest advice. The distinction is that their price reflects how they propose to deliver the work and the information they have. Independent cost advice helps you examine the brief, budget and design choices before committing to a particular solution or builder.

If you ask for an early figure, ask what it assumes: the size and extent of the work, specification, access, exclusions and VAT. A precise-looking total can still rest on very little information.

I explore this in Why ‘We’ll Just Ask a Contractor’ Is Usually a Mistake. The point is to understand what the figure can tell you, rather than treat it as a settled budget for a design that has yet to be developed.

You have an idea, but no drawings

Start with a brief and a realistic discussion about money. What do you want your home to do better? What are you willing and able to spend? Does that amount cover the whole project or just the building work?

You do not need a detailed measured document to start that conversation. Our free calculator gives an indicative building-cost range. The Budget Reality Check offers a quantity surveyor’s review and a discussion of your next steps. Neither is a detailed design cost plan.

You are comparing options or preparing planning drawings

This is a useful point for a cost plan for your design. With suitable drawings and sketches, we can assess the likely cost of the options while you still have room to change direction.

The aim is not to strip out everything you like. It is to understand the trade-offs. You may choose to spend more on something important to you, reduce the scope elsewhere or change the approach. Those should be conscious decisions.

As the design develops, keep the brief and budget under review. An estimate for an earlier scheme does not automatically remain valid after the scheme changes.

The detailed design is coming together

As the design progresses into more detailed drawings and specification, check that it still fits the budget, then prepare the information builders need to price it. A Schedule of Works can be prepared alongside the final drawings and specification, with gaps resolved before it is issued.

Assess prospective builders’ suitability and availability early. You want a manageable shortlist of people capable of doing this particular job, with clear information and enough time to price it properly.

You already have builders’ quotes

Compare the scope before comparing the totals.

Check exclusions, provisional sums, specifications and qualifications. If one figure is significantly lower, establish why.

Some differences can be resolved by asking for clarification. If the builders have priced fundamentally different scopes, a common Schedule of Works and revised prices may be needed.

A Budget Reality Check can help identify warning signs and the next questions to ask. It is not a full tender assessment. Detailed checking or contractor assessment needs an agreed scope of its own.

The work has started

The earlier documents still matter: they help establish what was included and the basis of the agreed price. Your immediate priority, though, is understanding the expected final cost.

Keep a record of changes, decisions, agreed prices and items still to be assessed. Allow for known commitments as well as money already paid. Contingency should remain visible; it should not become a way of hiding extra work or upgrades from the overall forecast.

If you need help establishing where the project stands, we can discuss a position review, with the scope and fee agreed for your project.

What does our help cost?

• Budget Reality Check: £195 including VAT.

• Design cost check: from £595 including VAT.

• Builder pricing pack: from £1,495 including VAT.

• Design cost check and builder pricing pack together: from £1,895 including VAT.

These are starting fees. We confirm the appropriate service, scope and fixed fee in writing before you pay. The £195 Reality Check fee is credited against a design cost check or builder pricing pack booked for the same project within three months, subject to the service terms.

Choose the next step that fits your project

My advice is to start with the decision you need to make, then get the information that helps you make it. Test affordability early, keep costs alongside the developing design, and give suitable builders a clear basis for pricing.

Try the free budget calculator, see our services for homeowners, or book a free 15-minute call with me if you are unsure where to start.