What information does a builder need to quote a home project properly?

A builder can give an early budget from limited information, but a comparable appointment quote needs a common description of the work, existing property, design decisions and responsibilities. The aim is to remove avoidable guessing before several builders price the same project.

Start with the current design

Issue a drawing register with revision dates: existing and proposed plans, elevations, sections and details relevant to the build. Include structural engineer information where needed, such as steel sizes and bearings, foundations, floor and roof alterations. Say clearly what remains to be designed. A planning drawing can show the rooms without defining the structure or finishes; see our planning-drawings guide.

Give each bidder the same set and record any later revision sent during tender. Otherwise one builder may price revision B and another revision D.

Write the scope and specification

List the work by area or trade, including demolition, making good, services, insulation, windows, doors, internal finishes, external works and waste where relevant. Define the chosen products and quality level, or a clearly labelled allowance where a choice has not been made. State whether the builder or homeowner supplies and installs each major item. A schedule of works describes the tasks; a specification describes how they are to be carried out and the materials or performance required.

Do not hide unresolved decisions in “standard finish.” That phrase means different things to different bidders. Our schedule of works guide shows how to structure the work.

Describe the site and constraints

Provide survey information and access details: occupied rooms, working hours, scaffold space, material storage, parking, neighbouring property, drainage, utilities and known asbestos or other hazards where relevant. Say what areas must remain usable and what protection and cleaning are expected. A contractor cannot reliably plan a roof opening, extension foundation or structural alteration without understanding the existing house and the practical route for work.

Identify the status of planning, building control, party wall matters and other approvals. Do not imply that permission resolves construction details or grants access to a neighbour’s land.

Give bidders a response format

Ask each builder for a price breakdown against the same work sections, a list of assumptions, exclusions, provisional sums, subcontract packages, lead times, proposed start and duration, crew approach and payment schedule. Allow them to raise queries before pricing. Record answers and send the same clarification to all bidders where it affects the common scope.

Then compare their qualifications, not just totals. A low price with several “by client” notes may be a different product from a complete price. The quote comparison guide explains how to reconcile the offers.

Use the right level of estimate for the stage

You do not need a fully detailed tender pack to ask whether a proposed project is broadly affordable. Call the early figure an assessment based on stated assumptions. Before signing a construction contract, resolve material design gaps and obtain prices for a common scope. Build Advocate’s Cost & Readiness Assessment shows what the current information supports and what should be completed before builder selection.