The cost of constructing a 100m² flat in London

The cost of constructing a 100m² flat in London in 2024 can vary significantly based on a number of factors, including location, specification, and design complexity. Here’s a detailed breakdown of the potential costs involved:

Basic Construction Costs
Per Square Meter Cost:
The cost of constructing a residential building in London typically ranges between £1,750 and £3,000 per square meter. For high-end specifications and finishes, this cost can increase to £4,000 or more per square meter​ (Urbanist Arch)​​ (Homebuilding & Renovating)​.
Therefore, for a 100m² flat, the basic construction cost would range from £175,000 to £300,000, potentially rising to £400,000 or more for luxury finishes.
Additional Costs
Professional Fees:

Architect Fees: Architects usually charge between 7% and 15% of the total build cost. For a mid-range project, this could be around £12,250 to £45,000​ (Homebuilding & Renovating)​.
Structural Engineer: Approximately £600 to £1,000.
Other Consultants: Including services consultants, party wall surveyors, and approved inspectors, these can add several thousand pounds to the overall cost​ (Architecture for London)​.
Planning and Regulatory Fees:

Planning Application Fees: £462 per new dwelling plus an additional fee for the planning portal.
Building Regulations Fees: These can range from £1,000 to £3,500 depending on the complexity of the project​ (Homebuilding & Renovating)​.
Utilities and Site Preparation:

Utility Connections: Connecting to water, electricity, and gas services typically costs between £15,000 and £25,000.
Site Preparation: Including demolition and site clearance, this can add £10,000 to £15,000​ (Homebuilding & Renovating)​.
External Works and Landscaping:

Landscaping and external works often constitute around 15% of the total build cost, which could be approximately £26,250 to £60,000​ (Homebuilding & Renovating)​.
Contingencies and Additional Considerations
Contingency Fund:

A contingency fund of around 10% to 15% of the total build cost is advisable to cover any unexpected expenses, adding another £17,500 to £45,000​ (Urbanist Arch)​.
VAT:

New build homes in the UK are zero-rated for VAT on construction costs, but VAT will apply to professional fees and other services.
Project Management:

Employing a main contractor or project manager to oversee the build can significantly affect costs. Project management fees might add an additional 10% to 15% of the construction cost​ (Urbanist Arch)​.
Example Calculation
For a mid-range 100m² flat with standard finishes:

Basic Construction Cost: £250,000 (at £2,500/m²)
Architect Fees (10%): £25,000
Structural Engineer and Other Consultants: £3,000
Planning and Regulatory Fees: £4,000
Utility Connections: £20,000
Site Preparation: £12,500
External Works and Landscaping: £37,500
Contingency Fund (15%): £37,500
Project Management: £25,000
Total Estimated Cost: £414,500

This is a rough estimate, and actual costs can vary based on specific project requirements, location, and market conditions. It’s advisable to engage with local contractors and professionals to get more accurate and tailored estimates.