This is a hands-on checklist, not another explainer — use it to gather everything builders need before you ask them to quote. The aim is simple: give every builder the same clear information so their prices are genuinely comparable, and so the finished work matches what you signed off. (For the 'why', see our guide on what drawings builders need.)
In short
If every builder prices a different version of your project, the quotes can't be compared. This is a practical checklist for putting together a drawing pack so several builders quote the same defined scope — and the build matches what you agreed. It won't fix a price, but it removes the guesswork that makes quotes drift.
Not sure which route applies to your property? Send Sean your postcode, a few photos and a short description for an honest first view — with no obligation.
Reviewed by Sean Corser, SC Design & Construction. Sean Corser helps Wirral homeowners with architectural design and drawing packs for extensions, loft conversions, planning and building regulations.
Last reviewed June 2026
Get your drawings and key decisions to a settled point first. Quoting from a rough sketch invites assumptions, and assumptions are where prices diverge — and where disputes start once work is under way.
Aim to hand each builder an identical pack and ask them to price the same scope. Work through the checklist below and fill the gaps before you send anything out.
Tick off each item you can provide. The more of these a builder has, the tighter and more comparable the quote.
| Include in your pack | Why it matters |
|---|---|
| Existing plans and elevations | Shows the starting point accurately |
| Proposed plans and elevations | Defines exactly what's being built |
| Sections where needed | Clarifies heights, levels and construction |
| Building-regulations details (where available) | Sets the construction standard being priced |
| Structural engineer drawings/calculations (where needed) | Removes risk around beams and openings |
| Specification notes | Pins down quality and materials |
| Drainage and utility assumptions (if relevant) | Avoids a common source of extra cost |
| Windows and doors scope | A big cost item that's easy to leave vague |
| Insulation, roof, floor and wall assumptions | Stops builders pricing different build-ups |
| Fixtures and finishes exclusions | Makes clear what's not in the builder's price |
| Planning decision notice and conditions (if approved) | Confirms what's actually permitted |
| Site constraints (access, parking, neighbours) | Affects programme and cost |
Ask each builder the same questions: what's included and excluded, how they handle changes (variations), what their programme looks like, whether the price is fixed or an estimate, and how stage payments work. Asking everyone the same things keeps the comparison fair.
Be wary of red flags: a quote far lower than the others (often because something's been left out), a price with no breakdown, reluctance to work to your drawings, or pressure to start immediately. A clear pack makes these easier to spot.
Line the quotes up against the same headings rather than just comparing bottom-line totals — the cheapest number isn't always the cheapest job.
| What to compare | Good sign | Watch out for |
|---|---|---|
| Scope priced | Matches your drawing pack | Vague 'allowances' for big items |
| Breakdown | Itemised by element | A single lump sum only |
| Exclusions | Clearly listed | Not stated — gaps appear later |
| Price basis | Fixed against the drawings | Open-ended 'estimate' that can move |
We prepare the drawing pack builders quote from — clear existing and proposed drawings, building-regulations drawings, and coordination with a structural engineer where needed.
We don't set builders' prices or carry out the work, and we won't promise a fixed cost — but a clear, complete pack is the single best way to get comparable quotes and keep control on site.
A few details are enough for an honest first view — with no obligation:
Need building regulations drawings? We can prepare them — clear, coordinated and ready for builders and building control.
External links open in a new tab. Always confirm your specific project with the relevant authority.
Send Sean a few photos and a short description of what you'd like to do. You'll get an honest first view with no obligation.