Loft Conversion Cost Calculator
Considering a loft conversion? Use our calculator to get a rough estimate of the potential costs involved. This tool provides an indicative figure based on common project parameters. For an accurate quote, always consult with professional builders and architects.
Understanding Loft Conversion Costs
A loft conversion is an excellent way to add valuable living space and potentially increase your property’s value. However, the costs can vary widely depending on a multitude of factors. Our calculator aims to give you a preliminary idea, but it’s crucial to understand what influences the final price.
Key Factors Influencing Cost:
- Type of Conversion:
- Velux/Rooflight: Generally the cheapest and simplest, involving adding windows to the existing roof structure. Minimal structural changes.
- Dormer: Involves adding a box-shaped structure to a pitched roof, creating more headroom and usable floor space. More complex than Velux.
- Hip-to-Gable: Suitable for properties with a hipped roof (sloping on all sides). One hipped side is replaced with a vertical gable wall, extending the roof ridge.
- Mansard: Often the most expensive, typically built at the rear of the property. It involves altering the roof structure significantly to create a nearly vertical wall and a flatter roof.
- Size of the Loft: Larger lofts naturally cost more due to increased materials, labor, and potentially more complex structural work.
- Location: Labor and material costs differ significantly across the UK. London and the South East are typically the most expensive regions.
- Level of Finish:
- Basic/Shell: Might include structural work, windows, and basic insulation, leaving you to complete plastering, electrics, plumbing, and decoration.
- Mid-Range: A completed space with standard quality fittings, plastered, basic electrics and plumbing, and ready for decoration.
- High-End: Premium materials, bespoke fittings, en-suite bathrooms with luxury fixtures, custom joinery, advanced lighting, etc.
- Structural Work: Reinforcing floor joists, adding steel beams (RSJs), or altering the roof structure can add significantly to costs.
- Roof Complexity: The existing roof shape and condition can impact the ease and cost of conversion.
- Stairs: The design and placement of a new staircase are critical and can vary in cost from simple straight flights to custom-made designs.
- Windows and Doors: The number, size, and type of windows (e.g., uPVC, timber, aluminium) and any doors will affect the price.
- Plumbing and Electrics: Adding bathrooms, radiators, new lighting circuits, and power sockets all contribute to the cost. An en-suite bathroom will be a major cost component.
- Insulation and Soundproofing: Meeting building regulations for thermal efficiency and soundproofing is essential and has associated costs.
- Professional Fees: Don’t forget architect fees for design and plans, structural engineer calculations, and potentially party wall surveyor fees.
- Planning Permission & Building Regulations: While many loft conversions fall under permitted development, some (especially in conservation areas or for larger designs) require planning permission. All require building regulations approval, which involves fees and inspections.
How to Use This Calculator
This tool considers the primary factors: loft type, size, location, and desired finish. Select the options that best match your project:
- Loft Type: Choose the structural style of conversion you’re planning.
- Loft Floor Area: Enter the approximate internal floor area you expect the conversion to create. You can enter this in square metres (sq m) or square feet (sq ft).
- Property Location: Select the region where your property is located, as this influences average costs.
- Level of Finish: Indicate whether you’re aiming for a basic, mid-range, or high-end specification.
Disclaimer: The figures provided by this calculator are estimates only and should not be considered a formal quote. Costs can vary based on individual property characteristics, specific design choices, contractor rates, market fluctuations in material prices, and unforeseen complications. Always obtain multiple detailed quotes from reputable local contractors before committing to a project.