A civil engineer (infrastructure) is a chartered professional who designs the external works and civil infrastructure for development sites. This covers road layout and geometry, earthworks, drainage networks, retaining walls, culverts and utility corridors. On residential and commercial development sites they are the lead designer for everything outside the building footprint. Their designs form the basis of Section 38 (road adoption) and Section 104 (sewer adoption) agreements with statutory authorities, and must meet the relevant highway authority standards before adoption as public infrastructure.
What they do
- Produce road layout and geometry designs for development sites
- Design earthworks including cut-and-fill balance and ground modelling
- Design surface water and foul drainage networks
- Design retaining walls, culverts and bridges for new development
- Prepare Section 38 adoptable road packages for highway authorities
- Produce utility corridor layouts and coordinate with statutory undertakers
- Prepare infrastructure drawings and specifications for contractors
- Liaise with the highway authority and adoption bodies throughout design
When you need one
A civil engineer for infrastructure is required on any development that involves new roads, drainage, earthworks or civil structures - typically from planning application stage through to adoption.
Typical costs (UK, 2025)
| Job type | Typical cost |
|---|---|
| Site infrastructure design (small development) | £1,200 - £4,000 |
| Earthworks design and specification | £1,500 - £5,000 |
| Drainage network design | £1,000 - £3,500 |
| Retaining wall design | £800 - £2,500 |
| Bridge or culvert design | £2,000 - £8,000+ |
| Full infrastructure design package | £4,000 - £20,000+ |
| Hourly rate | £85 - £155 / hr |
Costs vary significantly with site size, complexity and number of adoption agreements required. Always obtain at least two quotes and confirm the scope includes liaison with the highway authority.
Qualifications to look for
The primary qualification for civil and infrastructure engineers in the UK. Requires a recognised BEng or MEng degree, a minimum of four years' supervised professional experience, and a rigorous professional review. Check membership at ice.org.uk.
Many civil engineers working on development sites also hold MCIHT, particularly those leading on highway adoption and transport assessment work. Recognised by highway authorities across the UK.
How to find a reputable civil engineer
Frequently asked questions
What is the difference between a civil engineer and a structural engineer?
A structural engineer focuses on the structural integrity of buildings - beams, columns, foundations and load-bearing elements. A civil engineer focuses on infrastructure - roads, drainage, earthworks, bridges, retaining walls and site-wide civil works. Both hold CEng status, often through the Institution of Civil Engineers (ICE). On larger projects both disciplines are typically required.
What does infrastructure design for a housing development include?
Infrastructure design for a housing development includes road layout and geometry, drainage network, earthworks and cut-and-fill strategy, utility corridor design, retaining structures, street lighting design, and liaison with statutory authorities for adoptions under Section 38 (roads) and Section 104 (sewers). The civil engineer coordinates all these elements into a single infrastructure design package.
What is a ground model?
A ground model is a three-dimensional digital representation of existing ground levels across a site - produced from topographic survey data and used as the basis for earthworks design, infrastructure layout and drainage modelling. The civil engineer uses the ground model to calculate cut-and-fill volumes, design road gradients and position drainage structures.