Suddeco
Priced takeoff plus approved-planning-anchored concept design.
Professional guide · Updated 20 July 2026
UK extension cost estimating tools compared
A factual guide to choosing between early feasibility, detailed takeoff, builder estimating, job management and contractor tendering workflows.
Choose the job before the tool
The word “estimating” covers several distinct jobs. A product designed for a trade takeoff is not automatically the right choice for feasibility, and an end-to-end builder platform is not automatically the right choice for a formal tender team.
PlanSwift
Detailed plan-based measuring, counting and trade assemblies.
HBXL
Template-led estimates and documents for UK building firms.
Buildxact
Takeoff and estimating connected to job and cost management.
Access ConQuest
Preconstruction estimating, enquiries and bid comparison.
Honest side-by-side comparison
The strongest choice depends on what you need to produce, who needs to review it and what happens after the estimate. The table avoids numeric rankings because the products serve different operating models.
| Tool | Best fit | Strong points | Check before choosing |
|---|---|---|---|
| Early feasibility Suddeco |
Professionals who need a proposed extension concept and its priced scope to stay connected from the start. | Starts from an address or drawing; combines a priced takeoff with concept design informed by nearby approved planning. | Compare a specialist platform if your priority is deep tender adjudication, repeated trade assemblies or a full job-management suite. |
| Detailed takeoff PlanSwift |
Estimators and trade contractors measuring areas, lengths and counts from issued plan sets. | Plan measuring and counting, scale tools, symbol matching, custom parts and assemblies, cost calculations and exports. | Confirm system requirements, collaboration needs and how its estimating structure fits your existing rate and review process. |
| UK builder estimate HBXL EstimatorXpress |
Small and medium UK building firms pricing extensions, renovations, conversions and new-build work. | Ready-made project templates, hundreds of built-in estimating calculators and price books, quotes, material schedules, programmes and reports. | Takeoff capability varies by package, so confirm which edition covers plan tracing and the outputs your team needs. |
| Estimate to job Buildxact |
Builders and renovators who want estimating to flow into scheduling, cost tracking, site work and invoicing. | Online takeoff, estimating and quoting connected to supplier pricing, job management, scheduling and financial tracking. | Check whether its connected operating workflow is more important to you than specialist tender analysis or planning-led concept work. |
| Preconstruction Access ConQuest |
Contractor preconstruction teams managing formal estimating and tender workflows. | Digital takeoff, pricing libraries, enquiry tracking, bid comparison, valuations, templates and controlled team collaboration. | Its contractor-focused breadth may be more than a small firm needs for occasional domestic extension estimates. |
Disclosure: Suddeco publishes this guide and is one of the products compared. The competitor descriptions are based on their official pages, linked below. There is no sponsored ranking, and each competitor is given a clear “choose it when” case.
How to build a two-tool shortlist
Run the same recent extension through two likely candidates. Keep the drawings, scope assumptions and rates constant, then compare the time to review, the clarity of exclusions and the usefulness of the final output.
Choose Suddeco when
The question starts before a detailed tender set exists: what may be viable here, what could it look like, and what is the proposed scope likely to cost?
Choose PlanSwift when
Your core problem is repeated, detailed measurement and counting from plan sets across general or specialist trades.
Choose HBXL when
You are a UK builder who values ready-made job templates, calculators, price books and automatically produced commercial documents.
Choose Buildxact when
You want takeoff, estimate and quote data to continue into scheduling, job delivery, cost tracking and invoicing.
Choose Access ConQuest when
You run a contractor preconstruction process with enquiries, pricing libraries, bid comparisons, tender revisions and controlled collaboration.
Keep professional review
Whichever tool you choose, an estimator or QS should still own scope completeness, exclusions, rate quality, risk and the final commercial decision.
Where Suddeco is different
Price what you design, and anchor the design in real approvals
Most estimating workflows begin once a drawing set is ready. Suddeco can begin earlier, using an address or a drawing to keep concept, planning precedent and priced scope in one connected decision path.
1
Start with context
Use the address and nearby approved planning to shape the concept.
Use the address and nearby approved planning to shape the concept.
2
Keep design and scope together
Move from concept to a priced takeoff without treating them as separate guesses.
Move from concept to a priced takeoff without treating them as separate guesses.
3
Hand over clearer evidence
Give the team a visual proposal and defined scope to review before detailed delivery.
Give the team a visual proposal and defined scope to review before detailed delivery.
Frequently asked questions
Short answers to the questions UK builders, estimators and quantity surveyors ask when comparing extension estimating tools.
What is the best estimating software for a UK house extension?
There is no universal winner. Suddeco is designed for early feasibility where a priced takeoff and planning-anchored concept need to stay connected. PlanSwift focuses on detailed plan measurement, HBXL EstimatorXpress on UK builder estimates and documents, Buildxact on an estimate-to-job workflow, and Access ConQuest on contractor preconstruction and tendering.
What is the difference between a takeoff and an estimate?
A takeoff measures and counts the work shown on drawings. An estimate applies labour, material, plant, subcontract and overhead assumptions to that scope. Some products cover both stages, while others specialise in one part of the workflow.
Can estimating software replace a quantity surveyor or estimator?
No. Software can speed up measurement, calculation, document production and comparison, but a competent professional still needs to review scope, exclusions, rates, risk and the final commercial position.
Which tool is suited to extension feasibility before detailed drawings exist?
Suddeco is the option in this comparison aimed at the earlier feasibility stage. It connects a priced takeoff with concept design informed by approved planning around the address. The other products become strongest when the priority is detailed takeoff, estimating, job management or tendering.
When should I choose a specialist estimating platform instead?
Choose a specialist when your main requirement is repeated trade measurement, a template-led UK builder estimate, a connected estimating and job-management workflow, or formal contractor tender comparison. Test each shortlisted product against one real extension before committing.
Method and official sources
We compared product fit, takeoff approach, estimating workflow, downstream outputs and the strongest fair reason to choose each option. Claims were checked against official product information on 20 July 2026.