One of the first questions homeowners ask is how much a house extension will cost. The honest answer is that it depends on the property, the size of the extension, the specification, and the amount of structural work involved. A simple rear extension with a modest finish will not cost the same as a larger wraparound extension with extensive glazing and high-end finishes.

Core Cost Factors

The main factors that affect the total price include the size of the footprint, ground conditions, structural engineering requirements, and the level of internal finish.

• Foundation & Structure: Excavation, drainage, and steelwork form the backbone of the cost.
• Glazing & Light: Roof lanterns, bifold doors, and architectural glazing are major variables.
• Internal Finish: Kitchen installation, flooring, and bespoke cabinetry vary significantly by specification.

Why Realistic Quotations Matter

A low initial quote often indicates missing items or “budget” materials. At MBT Group, we believe in providing structured, realistic quotations that cover the true scope of work, helping you avoid unexpected costs later.

Get an Accurate Assessment

Rather than guessing, we recommend starting with a professional site visit. Book a free site survey with MBT Group to discuss your project and receive guidance tailored to your property.