Fictional demo. Computed live by the estimating engine from a template's default answers, default labour rates and dated catalogue allowances. It is not a real business, customer or supplier price.
Live demo
Single-storey extension
16.3 m² internal · £56,380.80 inc. VAT
£56,380.80
Selling price inc. VAT
£46,984.00
Before VAT
16.3 m²
Internal floor area · £2,886/m²
5 wks
550 person-hours of labour
Cost to selling price
Materials£13,900.90Labour (at cost)£16,495.05Provisional allowances£4,435.00Plant hire£695.00Direct cost£35,525.95Overheads — 10% of direct cost£3,552.60Contingency — 5% of direct cost£1,776.30Profit — 15% markup on cost£6,128.23Rounding to nearest £1.00£0.92Net selling price£46,984.00VAT at 20%£9,396.80Total£56,380.80
Pricing coverage
Cost backed by a price100%— of which verified (your prices)0%— of which catalogue allowances (dated 2026-09-24)41.1%— of which provisional allowances12.5%Lines missing a price0Stale prices0Assumptions that could move the price1
Selling price before VAT divided by internal floor area. A reasonableness check only — it does not replace the line-by-line estimate. Template status: provisional
By work package (at cost)
| Package | Materials | Labour | Allowances | Total |
|---|---|---|---|---|
| Preliminaries & site setup | £150.00 | £480.00 | £0.00 | £630.00 |
| Excavation & foundations | £747.50 | £1,350.75 | £0.00 | £2,098.25 |
| Floors | £1,066.00 | £1,172.40 | £0.00 | £2,238.40 |
| Structural elements | £0.00 | £1,680.00 | £2,700.00 | £4,380.00 |
| External walls | £2,821.90 | £2,311.20 | £0.00 | £5,133.10 |
| Roof | £1,658.00 | £4,396.20 | £0.00 | £6,054.20 |
| Windows & external doors | £4,220.00 | £990.00 | £0.00 | £5,210.00 |
| Drainage | £306.00 | £600.00 | £0.00 | £906.00 |
| Plumbing & heating | £329.00 | £324.00 | £0.00 | £653.00 |
| Electrical | £262.00 | £714.00 | £0.00 | £976.00 |
| Insulation & internal linings | £390.00 | £1,111.50 | £0.00 | £1,501.50 |
| Internal finishes | £170.50 | £1,275.00 | £0.00 | £1,445.50 |
| Scaffold & access | £0.00 | £0.00 | £585.00 | £585.00 |
| Plant hire | £695.00 | £0.00 | £0.00 | £695.00 |
| Waste removal | £1,780.00 | £0.00 | £0.00 | £1,780.00 |
| Deliveries | £0.00 | £0.00 | £250.00 | £250.00 |
| Testing & certification | £0.00 | £90.00 | £0.00 | £90.00 |
| Fees & approvals | £0.00 | £0.00 | £900.00 | £900.00 |
Provisional allowances (4)
Items that need a design, a supplier quotation or your confirmation. Edit the figure, or confirm it, on the review page. Material allowances appear on the customer's quote as provisional sums.
- Steel beam and structural design for 1 × 3m opening structural design required£2,700.00A load-bearing opening into the existing house needs a structural engineer's design, a steel beam with padstones and building control sign-off. Allowance covers design and steel supply; the builder's work is priced below.
- Material deliveries builder to confirm£250.00Delivery charges depend on the supplier and order size. Confirmed against supplier baskets when prices are verified.
- Scaffolding supplier quotation required£585.00Independent scaffold to 13m of elevation, for the build duration. Scaffold is quoted by the scaffolder; this is an allowance at £45/m.
- Building control fees regulatory£900.00Plan check and inspection fees vary by council and project value. Allowance only; confirm with your local authority or approved inspector.
Assumptions (10)
- Foundations: trench fill 600mm wide × 1.0m deep in GEN1 concrete under all new external walls.
- Ground floor: 100mm concrete slab on 150mm compacted hardcore with 100mm PIR insulation.
- could move the price Openings over 2.7m wide may need an engineer-specified lintel or steel; a heavy-duty catalogue lintel has been allowed.
- External walls: facing brick outer skin, 100mm full-fill insulated cavity, 100mm block inner skin.
- Lean-to roof at 22° in concrete interlocking tile, cut on site from C24 timber; rafter length 4.3m.
- Drainage: connect rainwater and any foul water to the existing system within 6m, capacity assumed adequate. Building over or near an existing sewer needs the water company's agreement.
- The existing consumer unit has spare capacity for the new circuits; if not, a new unit is extra.
- Heating: 2 radiators added to the existing system; the existing boiler is assumed to have capacity.
- No planning application fee, party wall surveyor or planning drawings are included. Permitted development or existing consent is assumed.
- Work to comply with the building regulations applying in England; design by others where a design is required.
Materials — 64 lines (measured → with waste → purchased)
| Item | Measured | + waste | Buy | Unit price | Cost | Price status |
|---|---|---|---|---|---|---|
| Underground drainage bend 110mm drainage · from drainage | 3 nr | 3 | 3 × each | £6.00 | £18.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Underground drainage pipe 110mm × 3m drainage · from drainage | 6 m | 6.60 | 3 × length | £14.00 | £42.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Bottle gully 110mm drainage · from drainage | 1 nr | 1 | 1 × each | £22.00 | £22.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Inspection chamber 450mm kit with cover drainage · from drainage | 1 nr | 1 | 1 × kit | £120.00 | £120.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Pea gravel 10mm drainage · from drainage | 0.60 m3 | 0.66 | 2 × bulk bag | £52.00 | £104.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| LED downlight (fire-rated, dimmable) electrical · from electrics | 6 nr | 6 | 6 × each | £9.00 | £54.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Socket/switch point: faceplate, back box, cable share electrical · from electrics | 8 nr | 8 | 8 × each | £22.00 | £176.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Mains smoke/heat alarm interlinked electrical · from electrics | 1 nr | 1 | 1 × each | £32.00 | £32.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Ready-mix concrete GEN1 (foundations) excavation foundations · from foundations | 5.46 m3 | 5.73 | 23 × m³ (0.25 m³ steps) | £32.50 | £747.50 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Aluminium bi-fold doors 3m wide ×1 external openings · from doors | 3 m | 3 | 3 × m | £820.00 | £2,460.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Pitched-roof window 780×1180 with flashing external openings · from lean-to | 2 nr | 2 | 2 × each | £530.00 | £1,060.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| uPVC double-glazed window (A-rated) per m² — 1.2×1.2m ×1 external openings · from windows | 1.44 m2 | 1.44 | 2 × m² | £350.00 | £700.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Concrete block 100mm 7.3N external walls · from below-dpc, cavity-wall | 364.6 nr | 382.8 | 6 × pack of 72 | £130.00 | £780.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Building sand external walls · from below-dpc, cavity-wall | 1.30 m3 | 1.43 | 3 × bulk bag | £52.00 | £156.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Full-fill cavity insulation 100mm external walls · from cavity-wall | 24.8 m2 | 26.6 | 7 × pack | £30.00 | £210.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Insulated cavity closer 2.4m external walls · from cavity-wall | 10.8 m | 10.8 | 5 × length | £6.00 | £30.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Cement 25kg external walls · from below-dpc, cavity-wall | 11.8 bag | 13.0 | 13 × bag | £6.50 | £84.50 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| DPC 100mm × 30m external walls · from cavity-wall | 26 m | 29.9 | 1 × roll | £9.00 | £9.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Facing brick (standard 65mm) external walls · from cavity-wall | 1485.6 nr | 1559.9 | 4 × pack of 500 | £300.00 | £1,200.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Steel cavity lintel 1800mm over window external walls · from cavity-wall | 1 nr | 1 | 1 × each | £75.00 | £75.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Steel cavity lintel 3600mm (heavy duty) over bifold external walls · from cavity-wall | 1 nr | 1 | 1 × each | £240.00 | £240.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Stainless wall ties 225mm external walls · from cavity-wall | 74.3 nr | 74.3 | 1 × box of 250 | £35.00 | £35.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Weep vent external walls · from cavity-wall | 6 nr | 6 | 6 × each | £0.40 | £2.40 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Damp-proof membrane 1200 gauge 4m × 25m floors · from slab | 16.3 m2 | 18.7 | 1 × roll | £45.00 | £45.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| MOT Type 1 sub-base 150mm compacted floors · from slab | 3.17 m3 | 3.49 | 7 × bulk bag | £48.00 | £336.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Reinforcement mesh A142 4.8m × 2.4m floors · from slab | 16.3 m2 | 18.7 | 2 × sheet | £32.00 | £64.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| PIR floor insulation 100mm floors · from slab | 16.3 m2 | 17.5 | 7 × sheet | £38.00 | £266.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Ready-mix concrete GEN3 100mm slab floors · from slab | 1.63 m3 | 1.71 | 7 × m³ (0.25 m³ steps) | £35.00 | £245.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Sand blinding 50mm floors · from slab | 0.81 m3 | 0.90 | 2 × bulk bag | £55.00 | £110.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Drywall adhesive 25kg (dot and dab) insulation linings · from linings | 24.8 m2 | 26.0 | 9 × bag | £8.00 | £72.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Drywall screws 38mm box of 1000 insulation linings · from ceiling | 488.4 nr | 488.4 | 1 × box | £12.00 | £12.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Loft insulation 270mm at ceiling level insulation linings · from lean-to | 16.3 m2 | 17.5 | 4 × m² (two rolls) | £42.50 | £170.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Plasterboard 12.5mm 2400×1200 insulation linings · from linings, ceiling | 41.0 m2 | 45.1 | 16 × sheet | £8.50 | £136.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Angle beads to reveals internal finishes · from skim | 10.8 m | 10.8 | 5 × length | £2.00 | £10.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Emulsion paint 10L (mist + two coats ≈ 60 m²) internal finishes · from decorating | 41.0 m2 | 41.0 | 1 × tub | £32.00 | £32.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Multi-finish plaster 25kg internal finishes · from skim | 41.0 m2 | 43.1 | 5 × bag | £9.50 | £47.50 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Satinwood 2.5L (≈ 20 m of skirting/architrave) internal finishes · from decorating | 13.2 m | 13.2 | 1 × tin | £28.00 | £28.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Scrim tape 90m internal finishes · from skim | 49.2 m | 49.2 | 1 × roll | £5.00 | £5.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| MDF skirting 145mm × 4.4m internal finishes · from skirting | 13.2 m | 14.5 | 4 × length | £12.00 | £48.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Acrow props & strongboys (set) per week plant · from knock-through | 1 wk | 1 | 1 × week | £60.00 | £60.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| 1t dumper hire per day plant · from foundations | 2 day | 2 | 2 × day | £70.00 | £140.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| 1.5t mini digger hire per day plant · from foundations | 2 day | 2 | 2 × day | £95.00 | £190.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Cement mixer hire per week plant · from prelims | 5 wk | 5 | 5 × week | £45.00 | £225.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Plant delivery/collection plant · from foundations | 1 nr | 1 | 1 × each | £80.00 | £80.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Push-fit fittings per radiator/appliance plumbing heating · from radiators | 2 nr | 2 | 2 × set | £18.00 | £36.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Plastic push-fit pipe 15mm 50m coil plumbing heating · from radiators | 16 m | 17.6 | 1 × coil | £45.00 | £45.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Double panel radiator 600×1000 with TRV & valves plumbing heating · from radiators | 2 nr | 2 | 2 × each | £124.00 | £248.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Site toilet hire per week preliminaries · from prelims | 5 wk | 5 | 5 × week | £30.00 | £150.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Breathable roofing membrane 50m² roof · from lean-to | 27.8 m2 | 31.9 | 1 × roll | £55.00 | £55.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| C24 treated timber 47×150 roof · from lean-to | 136.6 m | 150.3 | 151 × m | £3.50 | £528.50 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| uPVC downpipe 68mm × 2.5m with clips & shoe roof · from lean-to | 1 nr | 1 | 1 × each | £18.00 | £18.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Dry verge system per m roof · from lean-to | 12.1 m | 12.1 | 13 × m | £11.00 | £143.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| uPVC fascia board 175mm × 5m roof · from lean-to | 4.60 m | 5.06 | 2 × length | £32.00 | £64.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Lead/lead-free abutment flashing with cavity tray per m roof · from lean-to | 5 m | 5 | 5 × m | £28.00 | £140.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| uPVC half-round gutter 112mm × 4m roof · from lean-to | 4.60 m | 5.06 | 2 × length | £14.00 | £28.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Gutter bracket roof · from lean-to | 4.60 nr | 4.60 | 5 × each | £1.30 | £6.50 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Gutter fittings (outlet, stop ends, unions) per run roof · from lean-to | 1 nr | 1 | 1 × set | £25.00 | £25.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Roofing batten 25×50 treated (graded) roof · from lean-to | 80.6 m | 88.6 | 89 × m | £0.80 | £71.20 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| uPVC soffit board 300mm × 5m roof · from lean-to | 4.60 m | 5.06 | 2 × length | £30.00 | £60.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Tile clips and nails (per m² allowance) roof · from lean-to | 27.8 m2 | 27.8 | 28 × m² | £0.90 | £25.20 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Concrete interlocking tile roof · from lean-to | 277.8 nr | 291.7 | 292 × each | £1.60 | £467.20 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Wall plate and ledger roof · from lean-to | 10 m | 11 | 11 × m | £2.40 | £26.40 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| Muck-away of excavated spoil (grab lorry) waste · from foundations | 3 nr | 3 | 3 × load | £380.00 | £1,140.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
| 8-yard skip (mixed waste) waste · from knock-through, waste | 2 nr | 2 | 2 × each | £320.00 | £640.00 | Catalogue allowance BuildLegend catalogue · 2026-09-24 |
Labour — 34 activities
| Activity | Qty | Crew hrs | Person hrs | Rate basis | Cost |
|---|---|---|---|---|---|
| Excavate trenches and reduced level (machine) Groundworker · 0.60 h/m3 · min 8h · +4h setup | 12.8 m3 | 12 | 24 | 1× groundworker @ £30.00/hr + 1× labourer @ £30.00/hr blended | £720.00 |
| Place and level foundation concrete Groundworker · 0.80 h/m3 · min 4h | 5.46 m3 | 4.37 | 8.74 | 2× groundworker @ £30.00/hr blended | £262.20 |
| Blockwork below DPC Bricklayer · 0.70 h/m2 | 11.7 m2 | 8.19 | 12.29 | 1× bricklayer @ £30.00/hr + 0.5× labourer @ £30.00/hr blended | £368.55 |
| Hardcore, blind, DPM, insulation, mesh and pour slab Groundworker · 1.20 h/m2 · min 8h | 16.3 m2 | 19.54 | 39.08 | 2× groundworker @ £30.00/hr blended | £1,172.40 |
| Facing brickwork outer skin Bricklayer · 1.20 h/m2 · min 8h | 24.8 m2 | 29.71 | 44.57 | 1× bricklayer @ £30.00/hr + 0.5× labourer @ £30.00/hr blended | £1,336.95 |
| Blockwork inner skin Bricklayer · 0.70 h/m2 · min 8h | 24.8 m2 | 17.33 | 25.99 | 1× bricklayer @ £30.00/hr + 0.5× labourer @ £30.00/hr blended | £779.85 |
| Wall ties, cavity insulation and closers Bricklayer · 0.10 h/m2 | 24.8 m2 | 2.48 | 2.48 | 1× bricklayer @ £30.00/hr blended | £74.40 |
| Bed lintels Bricklayer · 1.00 h/nr | 2 nr | 2 | 4 | 1× bricklayer @ £30.00/hr + 1× labourer @ £30.00/hr blended | £120.00 |
| Cut lean-to roof: wall plate, ledger, rafters Carpenter / joiner · 1.20 h/m2 · min 8h | 27.8 m2 | 33.34 | 66.68 | 2× carpenter / joiner @ £30.00/hr blended | £2,000.40 |
| Ceiling joists Carpenter / joiner · 0.30 h/m2 | 25.8 m2 | 7.73 | 15.46 | 2× carpenter / joiner @ £30.00/hr blended | £463.80 |
| Breathable membrane and battens Roofer · 0.25 h/m2 · min 4h | 27.8 m2 | 6.95 | 13.9 | 1× roofer @ £30.00/hr + 1× labourer @ £30.00/hr blended | £417.00 |
| Lay concrete interlocking tiles Roofer · 0.60 h/m2 · min 8h | 27.8 m2 | 16.67 | 33.34 | 1× roofer @ £30.00/hr + 1× labourer @ £30.00/hr blended | £1,000.20 |
| Ridge, hip and verge details Roofer · 0.45 h/m | 12.1 m | 5.44 | 8.16 | 1× roofer @ £30.00/hr + 0.5× labourer @ £30.00/hr blended | £244.80 |
| Lay loft insulation Labourer · 0.15 h/m2 | 16.3 m2 | 2.44 | 2.44 | 1× labourer @ £30.00/hr blended | £73.20 |
| Abutment flashing and cavity tray Roofer · 0.60 h/m | 5 m | 3 | 3 | 1× roofer @ £30.00/hr blended | £90.00 |
| Fascia, soffit, guttering and downpipes Carpenter / joiner · 0.50 h/m · min 4h | 4.60 m | 4 | 6 | 1× carpenter / joiner @ £30.00/hr + 0.5× labourer @ £30.00/hr blended | £180.00 |
| Fit rooflights and flashings Roofer · 4.00 h/nr | 2 nr | 8 | 16 | 1× roofer @ £30.00/hr + 1× carpenter / joiner @ £30.00/hr blended | £480.00 |
| Fit bi-fold doors and threshold Carpenter / joiner · 6.00 h/nr | 1 nr | 6 | 12 | 2× carpenter / joiner @ £30.00/hr blended | £360.00 |
| Fit windows, seal and make good Carpenter / joiner · 2.50 h/nr | 1 nr | 2.5 | 5 | 2× carpenter / joiner @ £30.00/hr blended | £150.00 |
| Excavate, lay and backfill drainage run Groundworker · 1.00 h/m · min 6h | 6 m | 6 | 12 | 2× groundworker @ £30.00/hr blended | £360.00 |
| Install inspection chamber and connect Groundworker · 4.00 h/nr | 1 nr | 4 | 8 | 2× groundworker @ £30.00/hr blended | £240.00 |
| Builder's work: needle, prop, remove wall, set steel, make good General builder · 28.00 h/nr | 1 nr | 28 | 56 | 2× general builder @ £30.00/hr blended | £1,680.00 |
| Electrical first fix: cables, back boxes, circuits Electrician · 1.10 h/nr · min 4h | 14 nr | 15.4 | 15.4 | 1× electrician @ £30.00/hr blended | £462.00 |
| Electrical second fix: faceplates, fittings, connection Electrician · 0.60 h/nr · min 3h | 14 nr | 8.4 | 8.4 | 1× electrician @ £30.00/hr blended | £252.00 |
| Test, certify and notify (Part P / equivalent) Electrician · 3.00 h/nr | 1 nr | 3 | 3 | 1× electrician @ £30.00/hr blended | £90.00 |
| Heating first fix: run pipework from existing system Plumber / heating engineer · 0.30 h/m · min 4h | 16 m | 4.8 | 4.8 | 1× plumber / heating engineer @ £30.00/hr blended | £144.00 |
| Hang radiators, connect, balance and test Plumber / heating engineer · 3.00 h/nr | 2 nr | 6 | 6 | 1× plumber / heating engineer @ £30.00/hr blended | £180.00 |
| Dot and dab plasterboard to walls Plasterer · 0.45 h/m2 · min 4h | 24.8 m2 | 11.14 | 16.71 | 1× plasterer @ £30.00/hr + 0.5× labourer @ £30.00/hr blended | £501.30 |
| Board ceiling Plasterer · 0.55 h/m2 · min 4h | 16.3 m2 | 8.95 | 17.9 | 1× plasterer @ £30.00/hr + 1× labourer @ £30.00/hr blended | £537.00 |
| Skim walls and ceilings Plasterer · 0.35 h/m2 · min 4h | 41.0 m2 | 14.36 | 21.54 | 1× plasterer @ £30.00/hr + 0.5× labourer @ £30.00/hr blended | £646.20 |
| Fix skirting Carpenter / joiner · 0.30 h/m · min 2h | 13.2 m | 3.96 | 3.96 | 1× carpenter / joiner @ £30.00/hr blended | £118.80 |
| Mist coat and two coats emulsion to walls and ceilings Decorator · 0.35 h/m2 · min 4h | 41.0 m2 | 14.36 | 14.36 | 1× decorator @ £30.00/hr blended | £430.80 |
| Prime and two coats to woodwork Decorator · 0.20 h/m | 13.2 m | 2.64 | 2.64 | 1× decorator @ £30.00/hr blended | £79.20 |
| Site set-up, protection, welfare and daily clean General builder · 8.00 h/nr | 1 nr | 8 | 16 | 1× general builder @ £30.00/hr + 1× labourer @ £30.00/hr blended | £480.00 |
BuildLegend platform default v1 — provisional, derived from published UK estimating norms; validate against your own site records.
Measured geometry
| Module | Floor m² | New wall m | Net wall m² | Roof slope m² | Eaves m | Foundation m |
|---|---|---|---|---|---|---|
| Extension | 16.28 | 13.00 | 24.76 | 27.78 | 4.60 | 13.00 |