Civil engineering is the invisible half of every successful build. Done well, you never notice it. Done badly, you spend the next twenty years dealing with cracked slabs, blocked drains and sinking driveways. Here is a plain-English guide to what civil engineering actually covers on a small residential or commercial development in Redditch, Birmingham and the wider West Midlands.
What is “civil engineering” on a small development?
On a one- to twenty-unit housing scheme or a commercial unit, civil engineering typically covers everything that happens outside the four walls of the building:
- Site clearance, cut and fill, levelling and ground preparation
- Foundation design and installation (strip, trench fill, raft or piled)
- Retaining walls where levels change across the site
- Drainage: foul water, surface water and SuDS (sustainable urban drainage systems)
- Service trenches: incoming water, gas, electricity, fibre and ducting
- Access roads, bellmouths, kerbs and shared surfaces
- Final driveways, pathways and hard landscaping
Ground conditions in the West Midlands
Soil varies dramatically across our patch. Redditch and Bromsgrove sit on Mercia Mudstone (soft red clay) which shrinks and swells significantly with moisture. Birmingham and Solihull are a mix of boulder clay, sandstone and glacial deposits. Warwickshire tips into limestone and alluvial deposits closer to the Avon. Each affects the right foundation choice and the required depth.
We commission a site investigation (boreholes or trial pits) on any development of three units or more. For single-plot self-builds we usually get away with trial pit inspection, but the structural engineer makes that call.
Foundations: picking the right type
- Trench fill (mass concrete): Standard for most domestic sites with good ground to 1.2m depth. Fast and economical.
- Deep trench fill: Where tree roots or made ground require 1.8m+ depth. More concrete, more cost.
- Raft foundations: Where ground is uniformly poor or compressible. Spreads load over a wide area.
- Piled foundations with ring beam: For sites with highly variable ground, significant made ground, or where tree influence runs very deep. More expensive but often the only safe option.
Drainage: more than just pipes
Modern Building Regulations now require sustainable drainage on almost all new developments. On a small scheme that typically means attenuation storage (an oversized storm crate under the drive) to hold back surface water, with controlled release to the public sewer. Soakaways are only an option where ground permeability tests confirm they will work.
For foul drainage, you need to confirm there is capacity in the local sewer. Severn Trent will issue a s104 agreement for private sewers being adopted and a s106 for connection to the public network. We handle these approvals as part of our standard service.
Access and highways
Any new access onto an adopted road needs a s184 approval from Worcestershire County Council, Birmingham City Council or whichever highway authority covers your site. This can take 8-12 weeks and is often the pacing item on a small development start.
Who does what
On every CK Construction civil engineering project we work with a chartered structural and civil engineer to produce foundation drawings, drainage layouts and SuDS calculations. We handle the full suite of statutory submissions (Building Regs, s104, s106, s184 highways) so you deal with one team.
Typical cost ranges in 2026
- Groundworks and foundations for a single-plot self-build detached home: £25,000-£55,000
- Site civils for a 4-unit housing scheme (roads, drainage, foundations): £180,000-£320,000
- Commercial unit site civils (small industrial, 300-600 m²): £80,000-£160,000
Planning a development?
CK Construction has delivered civil engineering on small housing and commercial schemes across Redditch, Birmingham, Solihull and Warwickshire for over twenty-five years. Call us on 01527 521835 or use the contact form.