New-build house estimate.
New-build estimating covers everything from groundworks through to completion. This guide explains the typical cost breakdown as a percentage of total build, what is commonly missed, and how to benchmark against industry norms.
Authored by Alexandr Vreme & Maksym Vasylkov
Published — Next review
Who this guide is for
This guide is for developers, self-builders, and contractors pricing a new-build dwelling from scratch. Whether you are building a single custom home or a small terrace, the percentage-based breakdown provides a reliable framework for early-stage budgeting before detailed quantities are available.
Information needed
To prepare an accurate new-build estimate, you will need:
- Planning permission drawings and approved plans
- Structural calculations — foundation design, steelwork, roof trusses
- Ground conditions report — soil type, water table, bearing capacity
- Utilities connection points — water, gas, electricity, drainage, broadband
- NHBC or BLP warranty requirements and registration fees
- Building regulations compliance strategy — fabric, ventilation, SAP calcs
Typical work breakdown
Industry benchmarks for a new-build house break down as follows (as a percentage of total build cost):
| Substructure — foundations, ground floor slab, drainage | 12–18% |
| Superstructure frame — walls, floors, stairs | 20–25% |
| Roof — trusses, tiles, insulation, fascias | 10–12% |
| M&E — plumbing, heating, electrics, ventilation | 12–15% |
| Finishes — plaster, joinery, kitchen, bathrooms, decoration | 15–20% |
| External works — driveway, paths, landscaping, fencing | 8–12% |
| Preliminaries — site setup, welfare, management, scaffolding | 10–15% |
Commonly missed costs
New-build projects carry several costs that first-time estimators often overlook:
- Archaeological and ecology surveys required by planning conditions
- S106 contributions — affordable housing, education, infrastructure payments
- CIL (Community Infrastructure Levy) payments to the local authority
- Attenuation tanks and sustainable drainage systems (SuDS)
- Driveway and hardstanding — often budgeted separately but significant
- Landscaping — turf, planting, shrubs, trees as required by planning
- Boundary treatments — fencing, walls, gates
- NHBC/BLP inspection fees throughout the build
Miniature worked example
A 100 m² three-bedroom new-build detached house:
| Groundworks & foundations | £25,000 |
| Frame, roof, cladding | £55,000 |
| M&E (plumbing, electrics, heating, ventilation) | £20,000 |
| Finishes (plaster, joinery, kitchen, bathrooms, decor) | £35,000 |
| External works (driveway, paths, landscaping) | £15,000 |
| Preliminaries (scaffold, welfare, project management) | £18,000 |
| Total | £168,000 |
| Approx £1,680/m² | |
Excluding architect fees, planning costs, warranty registration, and VAT.
Questions to ask
- Have all planning conditions been reviewed for additional survey requirements?
- Is the foundation design suitable for the ground conditions identified in the site report?
- Have utility connection charges been quoted by the relevant providers?
- Does the budget include NHBC or BLP warranty fees and inspection costs?
- Have S106 contributions and CIL payments been calculated and allowed for?
- What is the provisional sum for external works — driveway, paths, landscaping?
Related guides
For smaller projects see our single-storey extension estimate guide. For commercial projects see commercial fit-out estimating.