Upload drawings and spec; we deliver an NRM-structured estimate with live prices, prelims, risk & inflation—eligible small residential jobs in 24 hours.

Online estimates can be fast but are they accurate enough to make decisions? This plain-English guide shows how to get dependable numbers and save time, using our Cost Estimator service. If you want deeper context on method and benchmarks, see RICS New Rules of Measurement – complete guide, our construction estimating guide, and the UK building cost estimator. Ready to price your project now? Request a Custom Estimate.

Executive Answer

In one line: Accurate online estimates come from clear scope, NRM-structured take-offs, live supplier pricing, and explicit allowances for prelims, risk and inflation delivered as a concise summary + detailed breakdown you can use to compare quotes like-for-like. Region: UK (Great Britain). Base date: Q4 2025. VAT stance: Costs here exclude VAT unless stated. Units: m², m, l/m, m³, mm. Currency: GBP.

Table of Contents

• Why Online Estimates Often Miss the Mark
• How We Make Online Estimates Accurate
• What You Get from Our Cost Estimator
• What We Need from You
• Which Online Estimate Do You Need?
• Programme and Turnarounds
• Regional Variation
• Inclusions and Exclusions
• Risks and Allowances
• Key Facts & Assumptions (At a Glance)
• FAQs
• Sources

Why Online Estimates Often Miss the Mark

Most “instant” calculators rely on generic £/m² ranges and ignore site constraints, specification detail, preliminaries and risk. That’s fine for a ballpark, but it’s not enough to brief a builder or compare quotes fairly. The result? Under-allocation for prelims, missed items (MEP, drainage, access), and budget drift later.

How We Make Online Estimates Accurate

Our process blends speed with professional rigour:

• NRM-structured take-off: We measure to the RICS New Rules of Measurement (NRM1/NRM2) so your output is consistent and comparable.
• Live pricing: We use current labour benchmarks and up-to-date supplier/merchant prices for key materials and kits.
• Prelims built from the method: Welfare, supervision, access, scaffolds, plant durations and logistics are costed, not guessed.
• Risk & inflation: Clear allowances by stage, separate from base rates; inflation to mid-point of construction.
• Assumptions log: We show what’s included, exclusions, provisional sums and price validity on page 1.

Outcome: an online estimate you can share with designers and builders, use to fine-tune scope, and turn into quotes without rewriting everything.

What You Get from Our Cost Estimator

• Executive summary (1 page): totals, allowances (prelims, risk, inflation), key assumptions, and next steps.
• Detailed breakdown: either elemental (NRM1) or trade/BOQ-style (NRM2) so tenders come back like-for-like.
• Downloadables: PDF summary + CSV line items for easy review/filtering.
• Options (if requested): alternates for spec changes (e.g., glazing, finishes, heating) with clear cost deltas.
• Quote-ready pack (optional): enquiry templates to send to trades and suppliers.

Next step: upload drawings and scope now for a tailored turnaround: Request a Custom Estimate.

What We Need from You

1. Drawings: latest plans/sections/elevations (PDF or DWG). Add structural and MEP info if available.
2. Specification & schedules: windows/doors, finishes, sanitaryware, heating/electrical notes.
3. Site info: photos, access constraints, parking, working hours, any surveys.
4. Programme: target start/finish, phasing, and whether weekend/extended hours apply.
5. Client-supplied items: PC sums or owner-procured items to include.

Which Online Estimate Do You Need?

Pick the deliverable that matches your stage and goal. All options are UK-specific, ex VAT, and aligned to Q4 2025 conditions.

Programme and Turnarounds

• Small residential estimate: typically 24hrs from complete information.
• Elemental cost plan (RIBA 3–4): around 1–2 weeks depending on design maturity.
• BOQ-style trade breakdown (single house-type): 1–3 weeks; longer for complex MEP or multi-plot.

We’ll confirm timescales at intake based on drawings, scope and preferred deliverable. For urgent turnarounds, mention your deadline in the Quick Quote form. RICS-aligned structure • Transparent prelims/OHP • CSV line items • Options/VE on request • 24-hour turnaround available for eligible small residential jobs.

Regional Variation

Inputs mirror local labour and supplier markets. London & the South East tend to the top of ranges; strong competition can narrow spreads elsewhere. If you’re building outside your usual patch, we’ll adjust prelims for travel, supervision and logistics.

Inclusions and Exclusions

Included as standard

• NRM-structured take-off and cost build-up (labour, materials, plant, prelims, risk, inflation, OHP).
• Assumptions/exclusions log and price validity notes.
• Executive summary PDF + CSV line items.

Available on request

• Alternates/VE options; two-scenario comparisons.
• Quote-ready enquiry packs for suppliers/trades.
• On-site measure or scope verification visit.

Not included

• Design/coordination beyond stated scope; statutory fees; utilities upgrades; abnormal ground conditions.
• Specialist surveys and temporary works design (can be arranged separately).
• VAT unless explicitly stated.

Risks and Allowances

• Contingency: typically 10–15% at RIBA 2–3, tapering to 5–10% at RIBA 4–5 when designs are fixed.
• Inflation: applied from base date to mid-point of construction; we state our index/assumption.
• Provisional sums: used only where scope is genuinely undefined, converted to firm quantities ASAP.

Cost disclaimer: Ranges reflect typical GB market conditions at Q4 2025 and indicative scopes. Always seek written quotes aligned to your drawings and programme.

Key Facts & Assumptions (At a Glance)

• Region & base date: Great Britain; Q4 2025; VAT excluded unless stated.
• Standards: RICS NRM1 (order-of-cost/elemental), NRM2 (BOQ), NRM3 (maintenance).
• Deliverables: Order-of-Cost, Elemental Plan, BOQ-style, Materials Take-Off.
• Turnarounds: 24hrs (small estimate); 1–2 weeks (elemental); 1–3 weeks (BOQ-style).
• Risk policy: contingency 10–15% early, 5–10% when designs fixed; inflation to project mid-point.
• Units & currency: m², m, l/m, m³, mm; GBP.

FAQs

How “accurate” is an online estimate?

Accuracy depends on information quality. With latest drawings/spec and site notes, our NRM-structured estimates are designed to brief builders and compare quotes fairly. We state assumptions and validity so you can see the limits.

Can you work from planning drawings?

Yes, for order-of-cost/elemental level. For BOQ-style detail and quote comparisons, technical drawings/specs are best.

Will you include prelims, OHP and risk?

Yes those are included transparently and summarised on page 1.

Do you provide editable outputs?

Yes: PDF summary plus Excel line items so you can filter, share and re-use.

How do I get suppliers to price like-for-like?

Use our BOQ-style/trade breakdown option and send the same scope documents to all suppliers. Our optional enquiry pack helps standardise returns.

Is VAT always 20%?

Most works are standard-rated at 20%, but some residential cases (new dwellings, specific energy-saving measures) can be zero/reduced-rated. Confirm eligibility and keep evidence.

Can you meet a tight deadline?

Often, yes. Tell us your deadline on the Quick Quote form and we’ll confirm feasibility at intake.

Sources

• RICS — New Rules of Measurement (NRM1/NRM2/NRM3)
• RIBA — Plan of Work (stages 0–7)
• HSE — CDM 2015 dutyholder summary
• HMRC — VAT Notice 708 and 708/6 (context for residential VAT treatment)

Next step: Request a Custom Estimate for your drawings and scope. We’ll confirm deliverable, turnaround and any options (VE, alternates) at intake.