Site Evaluation – What Every Homeowner and Builder Needs to Know

Thinking about adding a conservatory, extending your house, or buying a plot? The first thing you should do is a solid site evaluation. Skipping this step can lead to surprise cracks, unwanted costs, and long delays. This guide walks you through the basics, so you can spot red flags before they become full‑blown problems.

Why a Site Evaluation Matters

A site evaluation tells you how the ground, existing structures, and local rules will affect your project. In the UK, soil types change from chalk to clay in just a few miles, and each behaves differently under load. Knowing the soil helps you choose the right foundation, avoid subsidence, and keep your insurance happy.

Beyond the ground, a quick look at nearby utilities, drainage, and planning restrictions can save weeks of paperwork. If you overlook a hidden service pipe or a tree protected by local law, you’ll end up paying a contractor to redesign the whole thing. A proper evaluation also gives you confidence when talking to structural engineers – they’ll have the data they need to give you accurate advice.

Key Steps for a Thorough Site Evaluation

1. Check the ground. Hire a qualified geotechnical surveyor to take soil samples. They’ll tell you if the soil is stable, if you need a deeper pile, or if a moisture barrier is a must. Most homeowners can get a basic report for under £300, and it’s worth every penny.

2. Look for existing cracks. Walk around the building and measure any foundation cracks you see. Use a simple crack width chart – anything over 0.5 mm could be a sign of movement. Note the location, length, and direction of each crack; this info speeds up the engineer’s assessment.

3. Assess drainage. Poor drainage is a silent killer. Check that ground water flows away from the house, and that gutters and downspouts are clear. If water pools near the foundation, you’ll need to improve grading or install a French drain before any extension.

4. Verify planning permissions. In the UK, many small extensions fall under Permitted Development, but there are limits on height, size, and proximity to boundaries. A quick chat with your local council or a planning consultant can confirm whether you need a full application.

5. Review utility lines. Contact the local utility companies for a ‘one‑line’ diagram of gas, electricity, and water services. Knowing where they run helps you avoid hitting them during excavation and prevents costly delays.

Once you’ve gathered this information, compile it into a short report. Include photos, measurements, and any specialist recommendations. Share the report with your builder, architect, or contractor – they’ll appreciate the clarity and you’ll avoid endless back‑and‑forth questions.

Remember, a good site evaluation isn’t just a checklist; it’s a conversation with the land. Taking the time now means smoother construction, fewer surprise costs, and a finished project that feels right from day one.

Got a specific question about your plot? Drop a comment below or reach out for a quick chat. The more you know about your site, the more confident you’ll feel when the first shovel hits the ground.