How to Do Your Own Measured Survey (And When to Call a Professional)

If you’re planning a house extension, loft conversion, or renovation, one of the very first steps is a measured survey. This survey forms the foundation of all architectural drawings, planning applications, and building regulations submissions.

Some homeowners choose to carry out a basic measured survey themselves to save time or budget at the early feasibility stage. In this guide, we’ll explain how to do a simple measured survey, what tools you’ll need, common mistakes to avoid, and when a professional measured survey is essential.

What Is a Measured Survey?

A measured survey is an accurate record of your property’s existing layout and dimensions, including:

• Room sizes

• Wall thicknesses

• Door and window positions

• Ceiling heights

• External dimensions

• Ground levels (where required)

These measurements are used to create existing floor plans, elevations, and sections, which are required for:

• Planning permission

• Permitted Development drawings

• Building Regulations drawings

• Structural calculations

Without accurate measurements, drawings can be rejected or lead to costly redesigns later.

Can You Do a Measured Survey Yourself?

Yes — for early design or feasibility purposes, you can carry out a basic measured survey yourself if:

• The property is straightforward

• You only need internal layouts and approximate dimensions

• The survey is not being used for complex planning or construction

However, DIY surveys are not suitable for:

• Planning applications with tight constraints

• Building control approval

• Structural design

• Party wall matters

• Listed buildings or conservation areas

We’ll explain why later.

Tools You’ll Need

To complete a basic measured survey, you’ll need:

• 📏 Laser distance measurer (recommended for accuracy)

• 📐 Tape measure (for checks and small details)

• 📋 Clipboard or notebook

• ✏️ Pencil & eraser

• 📱 Smartphone (photos & reference)

• 📄 Graph paper (optional but helpful)

Step-by-Step: How to Measure Your House

1. Start with a Rough Sketch

Draw a simple outline of each floor:

• Ground floor

• First floor

• Loft (if accessible)

Don’t worry about scale yet — this is just a guide for recording dimensions.

2. Measure Room by Room

For each room, record:

• Length and width (wall to wall)

• Ceiling height

• Position of doors and windows

• Chimney breasts or structural walls

💡 Tip: Measure each room in at least two directions to catch inconsistencies.

3. Measure Wall Thicknesses

Wall thickness is critical for architectural drawings:

• Internal walls: usually 100–120mm

• External cavity walls: typically 300–325mm

If unsure, note it clearly — assumptions can cause errors later.

4. Measure Doors and Windows

Record:

• Width

• Height

• Distance from adjacent walls

• Sill height (for windows)

Take photos and label them — this helps your designer interpret the data correctly.

5. Measure the Overall Building

Externally, measure:

• Total width and depth of the house

• Rear projection depth

• Side access width (important for extensions)

If access is limited, note this clearly.

Common DIY Measured Survey Mistakes

❌ Missing wall thicknesses❌ Inconsistent measurements❌ No ceiling heights recorded❌ Forgetting structural elements❌ Guessing dimensions❌ No external measurements❌ No reference photos

These errors often result in:

• Redrawn plans

• Planning delays

• Additional fees

• Site issues during construction

Can I Send My DIY Measurements to an Architect?

Yes — and we often review client-provided measurements for early feasibility studies. However, if inaccuracies are found, we may recommend a professional measured survey before proceeding to planning or building regulations.

This approach saves you money upfront without risking approval issues later.