How to Write a Scope of Work for Building Projects

A scope of work is arguably the most important document on any building project. It defines what you will do, what you will not do, how you will do it, and what the finished result should look like. Without one, you are relying on verbal agreements and assumptions — and when those assumptions differ between you and the customer, disputes follow.

Yet many tradespeople still skip writing a proper scope of work. They send a price with a one-line description and hope everyone is on the same page. This guide shows you exactly how to write a scope of work that protects your business, manages customer expectations, and makes your quotes more compelling. We will cover what to include, walk through a complete example for a loft conversion, and highlight the mistakes that cause the most problems.

What Is a Scope of Work?

A scope of work (often abbreviated to SOW) is a detailed description of the work to be carried out on a project. It sits within your quote or proposal and acts as the definitive record of what has been agreed between you and the customer.

Think of it as the answer to three questions:

• What work will be done?
• How will it be done (materials, methods, standards)?
• What will not be done (exclusions)?

On large commercial projects, the scope of work is typically a separate, formal document prepared by an architect or project manager. On domestic projects — extensions, renovations, loft conversions — it is usually included as a section within your quote or proposal. The format matters less than the content. What matters is that both you and the customer have a clear, shared understanding of the project.

Why a Scope of Work Matters

Writing a scope of work takes time, and when you are busy, it is tempting to skip it and just send a price. Here is why that is a false economy.

It prevents scope creep. Scope creep is when the customer gradually asks for additional work that was not in the original agreement — "While you are at it, could you also..." Without a written scope, it is difficult to push back on these requests because there is no record of what was originally agreed. With a scope, you can point to the document and say "That was not included, but I am happy to price it as a variation."

It protects you in disputes. If a customer claims you agreed to include something you did not, your scope of work is your evidence. In the worst case, if a dispute reaches court or an ombudsman, the scope of work is the primary document the adjudicator will reference.

It builds customer confidence. A detailed scope shows the customer you have thought the project through properly. It demonstrates professionalism, thoroughness, and competence — all of which make the customer more likely to choose you over a competitor who sent a vague one-line quote.

It helps you price accurately. The process of writing a scope forces you to think through every task, every material, and every stage of the project. This makes it far less likely you will forget to include something in your price.

It sets expectations. A scope of work tells the customer exactly what to expect — and, crucially, what not to expect. This reduces the chance of disappointment and makes for a smoother project.

Sections to Include in Your Scope of Work

A well-structured scope of work for a building project should include the following sections.

Project Overview

A brief summary of the project in one or two paragraphs. This sets the context and ensures everyone is talking about the same thing. For example: "Construction of a single storey rear extension to provide an open-plan kitchen-diner, approximately twenty square metres, to the rear of the existing property at [address]."

Detailed Description of Works

This is the core of the scope. Break the project down by trade or by phase and describe each element of work in enough detail that there is no ambiguity. For each item, specify:

• What will be done
• What materials will be used (specific products or minimum standards)
• What the finished result should be

For example, rather than "fit new kitchen," write: "Supply and install customer's selected kitchen units (as per Kitchen Solutions order number 12345) including wall units, base units, island unit, laminate worktops, sink and mixer tap, and integrated appliance housings. Excludes supply and installation of appliances."

Exclusions

This section is as important as the description of works. List everything that is not included. Common exclusions on building projects include:

• Planning permission and Building Control applications (often handled by the customer or their architect)
• Structural engineer fees
• Party wall agreements
• Furniture removal and storage
• Decoration (if this is a separate phase)
• Landscaping and reinstatement of the garden
• Kitchen units and appliances (if supplied by the customer)
• Any work outside the defined project boundary

Materials and Specifications

Specify the key materials and products to be used. You do not need to list every screw and nail, but the major items should be defined — bricks, blocks, insulation type, window and door specifications, roofing material, and any customer-selected finishes. Where a specific product has been chosen, reference it by name and product code.

Standards and Compliance

State the standards the work will comply with — Building Regulations, British Standards, manufacturer's installation guidelines. For example: "All electrical work to comply with BS 7671 (IET Wiring Regulations) and Part P of the Building Regulations. All structural work to comply with the structural engineer's calculations and Building Regulations Part A."

Programme and Timeline

Include an estimated programme showing the key stages and their expected duration. This helps the customer plan and gives you a framework for managing the project. A simple table or list is sufficient — no need for a formal Gantt chart on domestic projects.

Variations Procedure

Explain how changes to the scope will be handled. A standard clause might read: "Any work requested by the client that is not included in this scope of work will be treated as a variation. Variations will be priced separately and must be agreed in writing before the additional work commences."

Example Scope of Work: Loft Conversion

Here is an example scope of work for a dormer loft conversion. This gives you a template you can adapt for your own projects.

Project Overview: Rear dormer loft conversion to an existing three-bedroom semi-detached house at [address], to create one additional bedroom with en-suite shower room. Approximately twenty-five square metres of usable floor space.

Structural Works:

• Form new floor structure using engineered timber joists to structural engineer's specification
• Install steel beams as per structural engineer's calculations (two number UB sections)
• Construct rear dormer in timber frame with flat roof, clad externally in GRP fibreglass to match existing
• Form staircase opening in existing first-floor ceiling and install new staircase (softwood, straight flight)
• Install Velux roof windows to front roof slope (two number, size MK06)

Insulation and Fire Protection:

• Insulate all external walls and roof slopes to meet current Building Regulations (Part L)
• Install thirty-minute fire-resistant doors to loft room, en-suite, and all existing bedrooms
• Install mains-wired interlinked smoke and heat detectors throughout the property as required by Building Control
• Fire-line existing stairwell ceiling and walls with pink fire-rated plasterboard where required

Plumbing:

• Install new soil and vent pipe to serve en-suite WC and shower
• Supply and fit close-coupled WC, wall-hung basin, and thermostatic shower with glass screen
• Extend hot and cold water supply from existing first-floor distribution to loft level
• Install heated towel rail in en-suite

Electrics:

• New lighting circuits to bedroom and en-suite (LED downlights throughout)
• New ring main circuit with six double socket outlets in bedroom and two in en-suite
• TV point and BT socket to bedroom
• Extractor fan to en-suite (timer and humidity controlled)
• All works to comply with Part P and BS 7671 — EIC to be issued on completion

Finishes:

• Plaster all walls and ceilings with two-coat skim finish
• Tile en-suite walls (full height) and floor with customer-selected tiles
• Install laminate flooring to bedroom (customer-selected)
• Fit skirting boards, architraves, and door linings throughout
• Paint all new surfaces with one mist coat and two coats of emulsion (white — customer to advise if colour is required)

Exclusions:

• Planning permission application (not required for this project under permitted development)
• Structural engineer's fees (to be arranged by client — drawings required before work commences)
• Building Control fees (payable directly by client to local authority)
• Furniture, curtains, blinds, and decoration beyond the painting described above
• Any works outside the loft conversion boundary

Common Mistakes to Avoid

Being too vague. A scope that says "build extension as discussed" is worthless. Be specific about every element — dimensions, materials, finishes, and quantities. If it is worth doing, it is worth writing down.

Forgetting exclusions. Customers will assume anything not explicitly excluded is included. If you are not responsible for decoration, skip hire, landscaping, or cleaning, say so in the exclusions section.

Using jargon without explanation. Not every customer knows what "first fix" means, or what DPC stands for. Either use plain English or include brief explanations. This is especially important for the scope of work, which the customer needs to understand and agree to.

Not updating the scope when things change. If the customer requests changes during the project, update the scope in writing and get it agreed before proceeding. A verbal agreement to change the scope is a recipe for disputes.

Confusing scope with specification. The scope describes what will be done. The specification describes how it will be done and to what standard. On large projects, these are separate documents. On smaller domestic projects, they are often combined — which is fine, as long as both elements are covered.

Scope of Work vs Specification — What Is the Difference?

These terms are often used interchangeably, but they serve different purposes.

A scope of work defines the boundaries of the project — what is in and what is out. It answers "What are we doing?" A specification defines the standards, methods, and materials — how the work will be done. It answers "How are we doing it?"

On a domestic project, you might combine both into a single document. For example, your scope might say "Install new consumer unit" (that is the scope — defining the task) and "Hager sixteen-way dual RCBO board, model VML916CUSPDRK" (that is the specification — defining the product and standard).

On larger commercial projects, the specification is a separate document, often prepared by the architect, and it runs to many pages covering every material, method, and standard in detail. The scope sits above the specification and defines the overall project boundaries.

For most domestic tradespeople, combining both into a clear, comprehensive scope section within your quote or proposal is perfectly adequate. Tools like QuoteSmith generate this automatically — you describe the job and the AI creates a detailed scope covering the works, materials, exclusions, and standards, all formatted professionally in a branded PDF proposal.

Frequently Asked Questions

What is a scope of work in construction?

A scope of work is a document that defines exactly what work will be carried out on a construction project. It describes the tasks to be completed, the materials to be used, the standards to be met, and the boundaries of the project. It forms part of the contract between the builder and the client and is the primary reference if any disputes arise about what was agreed.

What is the difference between a scope of work and a specification?

A scope of work describes what work will be done and the overall boundaries of the project. A specification describes how the work will be done and to what standard, including specific materials, methods, and quality requirements. On smaller domestic projects, the two are often combined into a single document. On larger commercial projects, they are usually separate.

Why is a scope of work important for building projects?

A scope of work protects both the builder and the client. For the builder, it defines the limits of the work and prevents scope creep where additional tasks are expected without additional payment. For the client, it provides a clear record of what they are paying for and what to expect on completion. It also forms the basis for resolving disputes, managing variations, and ensuring the project stays on track.

How detailed should a scope of work be?

A scope of work should be detailed enough that both parties have the same understanding of the project. For small jobs like fitting a kitchen, a one to two page scope covering the key tasks and exclusions is sufficient. For larger projects like extensions or loft conversions, the scope should run to several pages and cover every trade, every material specification, and every exclusion. The general rule is: if something could be misunderstood, it should be written down.