Attic Conversion Cost: What You’ll Actually Pay in the UK
Thinking about turning that dusty loft into a bedroom, office or playroom? The first thing on everyone’s mind is the price tag. While the headline figure can swing wildly, understanding where every pound goes makes the project less scary and helps you stay on budget.
Breakdown of the Main Cost Drivers
1. Planning and Design: Even if most attic projects fall under permitted development, you’ll still need a structural engineer’s report and a designer’s drawings. Expect £500‑£1,200 for basic plans, but complex roof shapes or heritage homes can push the cost to £2,000.
2. Structural Work: Reinforcing joists, adding new floor beams or installing a stairwell are the biggest bite. A typical reinforcement job runs £1,500‑£3,500, while a full‑scale stair addition (including landing) can cost £2,000‑£4,000.
3. Insulation & Ventilation: A warm attic needs proper insulation to avoid cold spots and condensation. Spray foam or rigid board insulation runs about £15‑£30 per square metre, so for a 20 m² loft you’re looking at £300‑£600.
4. Windows & Rooflights: Skylights are popular for natural light, but they’re pricey. A standard roof window starts at £600, with larger dormer‑style units reaching £2,000 plus installation.
5. Finishes: Dry‑lining, plastering, flooring, and decoration add the finishing touches. Budget £30‑£50 per square metre for plaster and finishing, and £40‑£80 per square metre for flooring, depending on material.
Hidden Costs You Might Forget
Many homeowners underestimate the extra €‑effects. Plumbing for bathrooms, electrical wiring for lighting, and fire safety measures (like fire‑rated doors) can each add £500‑£1,500. If your loft has limited headroom, you may need to raise the roofline – a major structural change that can cost £5,000‑£10,000.
Permitted development checks, waste removal, and contractor insurance also eat into your budget. A safe rule of thumb is to add a 10‑15% contingency to cover those surprise expenses.
Regional differences matter, too. London‑area projects tend to be 15‑20% higher than those in the North West because of labour rates and material availability.
To keep costs down, consider these simple tips:
- Get at least three quotes from reputable builders – price comparisons reveal hidden fees.
- Reuse existing windows or doors where possible.
- Choose a DIY‑friendly finish like laminate flooring instead of hardwood.
- Plan your staircase early; a prefabricated stair kit can save £500‑£1,000.
- Schedule work in the off‑season (autumn/winter) when contractors may offer lower rates.
In a nutshell, a standard attic conversion in the UK usually lands between £15,000 and £30,000, including design, labour, and finishes. Luxury conversions with dormer extensions or high‑spec finishes can top £50,000.
By mapping out each cost component, adding a modest contingency, and hunting for savings, you’ll turn that loft into a livable space without blowing your budget.
