Whole Home Renovation Scenario: 85 sq m High-End Refresh

The Project

James and Emma bought a 1980s two-bedroom flat needing complete modernization. At 85 sq m (915 sq ft), it's a decent size but felt cramped due to dated layout and finishes. They planned a comprehensive high-end renovation including knocking through to create open-plan living, completely refitting the kitchen and bathroom, rewiring, new flooring throughout, and premium finishes.

This is a significant project requiring careful planning, multiple trades, and substantial budget. They approached it methodically, understanding that whole-home renovations always encounter unexpected issues.

Using the Calculator

James and Emma started with the calculator to understand the scale of investment:

1. Room type: Whole home
2. Size: 85 sq m
3. Finish level: High-end
4. Contingency: 15% (higher than default—wise for whole-home projects with structural work)

The calculator estimated £127,500-212,500 for the complete project (£1,500-2,500 per sq m). This sobering figure helped them understand that "high-end whole home" means substantial investment. They secured a renovation mortgage and moved in with family for the duration.

The Detailed Breakdown

Here's how their actual project broke down:

1. Structural Work (£12,000)

Removing the wall between kitchen and living room required:

• Structural engineer survey and calculations: £1,200
• Building control application and inspections: £800
• Steel beam supply and installation: £4,500
• Wall removal, making good, and finishing: £3,500
• Temporary supports and safety measures: £2,000

This single change transformed the flat's feel but represented 7% of the total budget before any actual room improvements.

2. Complete Rewiring (£6,500)

Original 1980s wiring didn't meet modern standards and couldn't support their electrical needs:

• Full rewire with new consumer unit
• Recessed LED spotlights throughout
• Data points in living areas and bedrooms
• USB sockets in key locations
• Building control certification

Rewiring required lifting floorboards and chasing walls—messy but essential. They timed this before plastering to minimize disruption.

3. New Central Heating (£8,500)

Replacing the old boiler and upgrading to a modern system:

• New combi boiler with 10-year warranty: £2,500
• Underfloor heating in kitchen/dining area: £2,500
• New designer radiators in bedrooms and bathroom: £1,800
• Complete system upgrade and flush: £1,200
• Smart thermostatic controls: £500

4. Kitchen (£28,000)

A significant portion of the budget went to the open-plan kitchen:

• High-end handleless units with soft-close: £12,000
• Quartz worktops and splashback: £4,500
• Integrated appliances (oven, hob, dishwasher, fridge-freezer): £6,000
• Sink, taps, and waste system: £1,200
• Installation, plumbing, and electrics: £4,300

They sourced cabinets directly from a mid-tier manufacturer rather than using a kitchen showroom, saving around £5,000 vs showroom prices for equivalent quality.

5. Bathroom (£14,500)

Complete bathroom refit with premium fixtures:

• Walk-in shower with glass screen and rainfall head: £2,800
• Freestanding bath: £1,600
• Wall-hung toilet and concealed cistern: £800
• Designer sink and vanity unit: £1,200
• Large format porcelain tiles (walls and floor): £2,500
• Underfloor heating mat: £800
• Mirror cabinet with integrated lighting: £600
• Installation (plumbing, tiling, electrical): £4,200

6. Flooring Throughout (£8,500)

They chose continuous engineered oak flooring in living areas and bedrooms (65 sq m at £80/sq m installed) plus large tiles in entrance and utility areas. Continuous flooring makes open-plan spaces feel larger and more cohesive.

7. Plastering and Decoration (£9,500)

After structural and electrical work, extensive making-good was needed:

• Replastering walls affected by electrical and structural work: £4,500
• Coving and finishing details: £1,200
• Complete redecoration in premium paints: £3,800

8. Doors and Joinery (£7,200)

• Five new internal doors with modern frames and architraves: £2,500
• Built-in wardrobes in both bedrooms: £3,500
• Shelving and alcove storage in living room: £1,200

9. Windows and Bi-Fold Doors (£9,500)

Replacing old double-glazing with modern units plus adding bi-fold doors from living space to balcony—a major feature that adds value and desirability.

10. Project Management and Design (£8,000)

They hired a project manager to coordinate trades, order materials, and manage the schedule. For a project this complex, the 5% fee (typical range is 10-15% but they negotiated) saved them stress and likely prevented costly mistakes or delays.

11. Miscellaneous and Sundries (£5,000)

Light switches and sockets, door handles, curtain rails, touch-up materials, waste disposal (three large skips), cleaning, and dozens of small items that accumulate on large projects.

12. Contingency Used (£18,000)

Their 15% contingency covered several unexpected issues:

• Asbestos removal from old floor tiles: £2,500
• Additional structural support required above steel beam: £4,000
• Bathroom plumbing more complex than expected (concrete floor): £3,500
• Extra electrical points requested during work: £1,500
• Extending screed in kitchen area for underfloor heating: £2,200
• Delays requiring additional interim accommodation: £1,800
• Change of mind on kitchen handles (upgraded to integrated): £2,500

They ended up using most of their contingency—not unusual for whole-home projects with structural changes. Without it, they'd have faced difficult compromises or emergency borrowing.

Timeline and Living Arrangements

The project took 14 weeks from first trade on site to final completion:

• Weeks 1-2: Strip out, structural work, first-fix electrics and plumbing
• Weeks 3-4: Rewiring, heating system installation, asbestos removal
• Weeks 5-6: Windows and bi-fold doors, plastering begins
• Weeks 7-8: Kitchen and bathroom installation
• Weeks 9-10: Flooring, tiling, second-fix electrics
• Weeks 11-12: Joinery, decoration, built-in furniture
• Weeks 13-14: Finishing touches, snagging, deep clean

James and Emma moved back in after 14 weeks. They'd budgeted for 12 but delays (waiting for building control inspection, asbestos removal, and kitchen units arriving late) extended the timeline. They stayed with Emma's parents, saving on rental costs but adding stress.

What They Learned

• High-end doesn't mean premium brands everywhere: They saved thousands sourcing kitchen units and bathroom fixtures online rather than showroom prices, achieving similar quality.
• Whole-home projects always find surprises: Asbestos, structural issues, poor original installation—budget generously for contingency.
• Project management was worth it: The £8,000 fee saved them countless hours, prevented several costly mistakes, and kept trades coordinated.
• Living elsewhere adds hidden costs: Even staying with family meant extra travel, eating out more, storage costs—budget £2,000-3,000 for lifestyle disruption.
• Phasing wasn't realistic for them: Once you've moved out and opened up the flat, you might as well complete everything. Phasing works better when you can live in parts of the property.
• The result adds significant value: Estate agents valued the renovated flat at £60,000-70,000 more than purchase price—not a profit after renovation costs, but substantial added equity.

Would They Do It Again?

Despite the stress and cost overruns, James and Emma are thrilled with the result. The flat feels like a different property—open, modern, and exactly to their taste. Key takeaway: "Whole-home renovations are enormous undertakings. We're glad we did it, but we massively underestimated the stress and disruption. Budget more time and money than you think you need."