Exterior, Interior, or Both

When calculating your renovation budget, distinguishing whether your focus is on the interior, exterior, or both can help clarify overall costs.

Interior renovation

A complete interior renovation, often called an interior refurbishment, includes renewing surfaces (floors, walls, ceilings), updating bathrooms and kitchens, improving plumbing, and modernising electrical systems. This is more comprehensive than merely redecorating. In Hillingdon, many 1930s semis take well to interior refurbishments that combine older layouts with open-plan kitchens, appealing to modern families.

Based on industry data and past projects, smaller interior overhauls might start near £650 per m², while large-scale or higher-end ones can approach £2,000 per m². On average, around £1,100 per m² is a typical figure for the entire job, including materials purchased by the homeowner. Final totals vary substantially, depending on design choices and any on-site complications.

Exterior renovation

An exterior renovation might include:

• Drainage works
• Added insulation
• Re-pointing walls
• Re-rendering or cladding
• Roof renewal or repairs
• Fitting new windows and doors

These costs differ widely, driven by house size, materials, height, location, and repairs needed. Typically, £400–£700 per m² (wall area) is cited. Simpler or smaller undertakings might be £250–£400, while premium or complex ones can surpass £700–£1,200+ per m². Around Hillingdon, many homes exhibit brick or pebble-dash exteriors dating back to mid-century developments, which may require specific approaches to match the original look.

Both Interior and Exterior

Combining interior and exterior renovations raises costs considerably. A dual project usually starts near £1,500 per m², reaching £3,500 per m² for elaborate designs. It nonetheless remains cheaper than a new build, since major structural elements remain. Industry data suggests new-build houses in the UK commonly cost about £2,600 per m² including VAT, a benchmark for comparing full-scale refurbishments.

Complete Home Renovation in Hillingdon

A comprehensive renovation in Hillingdon allows homeowners to fuse the borough’s suburban appeal with modern updates for better comfort and value. Bounded by green spaces and major routes like the M4, Hillingdon offers a mix of 1930s semis, post-war estates, and some Victorian terraces. Renovating these varied properties often means uniting classic layouts (like bay-fronted living rooms) with contemporary kitchens or bigger living zones suited to family life.

Local labour costs generally stay below central London’s highest rates, although they still carry a London premium. If your home is near historical spots such as Uxbridge or in a conservation area like parts of Ickenham Village, external modifications—like new windows or roof finishes—may need council checks. On the other hand, internal refurbishments typically sail through if they avoid structural alterations requiring permission. Installing new insulation or upgrading older boilers can bring significant warmth benefits, particularly in houses from the mid-20th century.

Whether you have a chalet bungalow in Northwood Hills or a terraced home in Hayes, aligning a thorough makeover with Hillingdon’s family-friendly environment can boost both immediate comfort and future resale value. Loft conversions often prove especially popular, turning unused attic spaces into extra bedrooms or work areas. By partnering with builders who routinely tackle Hillingdon’s housing stock, you stand a good chance of securing accurate quotes and an efficient timetable. All in all, a well-organised refurbishment in Hillingdon can effectively combine suburban tranquillity with contemporary design features.

What Drives the Cost in a Complete Renovation?

Though per-square-metre benchmarks are useful, multiple factors can tilt your final bill higher or lower.

Size
How large your home is, or how large a part of it you are renovating, will naturally be decisive for the total cost. Larger homes might achieve marginal savings by spreading out certain overheads.

Complexity
Any home with more bathrooms, unique period features, or intricate design aspects generally costs more to renovate than simpler structures.

Number of bathrooms
Bathrooms or wet rooms remain some of the priciest areas to update. The Federation of Master Builders estimates a full bathroom renovation usually sits between £20,000 and £32,000, depending on style. Kitchens similarly boost average per-m² costs over standard rooms.

Structural modifications
If you’re removing load-bearing walls or making major structural changes, expenses rise beyond straightforward reconfiguration of non-structural parts. Such tasks may need specialist input from engineers, adding to the budget.

Materials
Homeowners can exert significant budget control through material selection—particularly for kitchens or bathrooms. Fundamental building materials don’t vary as dramatically in price, but luxury fittings will expand your outlay.

Choice of contractor
Finally, the builder or firm you pick matters greatly. It’s wise to solicit multiple quotes, cross-check references, and look for accreditations. Organised bodies like the Federation of Master Builders or TrustMark, help you discover reputable professionals.

What's Included in the Contractor's Quote?

Ensuring clarity on what’s included in your contractor’s bid is key from the outset. Typically, it covers all core labour across trades plus standard materials for the renovation. However, “finishing materials” can be left to the homeowner’s discretion.

These finishing materials often comprise kitchen units, bathroom suites, taps, toilets, floor coverings, and tile. As noted, these may vary significantly in cost. A basic kitchen could be £5,000, while premium or bespoke options cost tens of thousands. Kitchen installation normally costs £1,000–£3,000 if arranged via the kitchen supplier.

Likewise, flooring and tiling come under finishing. Monitoring sales or drawing on the contractor’s trade discounts can help. Tile or wood flooring might start at £20 per m², but high-end lines cost more.

Bathrooms similarly see big price spreads. Contractors might have set supplier deals, though it’s sensible to compare. A small bathroom might be fitted out for around £1,000, but most opt for more comfortable designs. Typically, your contractor quote includes the labour.

In Hillingdon, families often balance practical mid-range kitchen and bathroom finishes with touches like heated towel rails or energy-saving appliances.

Cost Breakdown for Individual Elements

Previously, we reviewed the square metre approach for overall budgets. Below is an illustration from a 230 m² detached home that underwent total interior-exterior renovation. Though specifics fluctuate, it offers a broad sense of how costs might be allocated:

Contractor’s quote (labour + materials):

• Windows (20 + delivery): £27,000
• Creating a new external window opening: £3,200
• Replacing cladding + insulation: £33,000
• Roof replacement: £21,500
• Drainage: £12,800
• Bathroom (excl. tiles/fixtures, plumber incl.): £19,000
• WC room 1 (with plumber): £3,600
• WC room 2 (with plumber): £3,600
• Utility room (with plumber): £10,800
• New plumbing: £18,400
• External/patio doors: £4,800
• Balanced ventilation: £9,600
• Interior surfaces (walls, floors, ceilings): £41,600
• Internal doors: £6,000
• Architraves, linings, transitions: £2,000
• Electrical works (entire house): £29,600
• Single garage (attached): £14,400
• Waste handling: £4,800
• Demolition, scaffolding, site setup: £24,000
• Interior designer: £6,000
• Architect: £4,000
  Subtotal (Contractor): £300,800

Client’s separate purchases:

• Tiles (bathroom, WC, utility, hallway): £4,800
• Bathroom fixtures (1 bathroom, 2 WCs): £6,400
• Kitchen units: £24,000
• Flooring: £10,000
  Sum of own purchases: £45,200

Grand total: £346,000

Hence, the job finished at around £1,500 per m², somewhat under the norm for an interior-exterior revamp of this nature.

Building Regulations for a Complete Home Renovation (UK)

Large refurbishment projects must uphold Building Regulations to guarantee safety, energy efficiency, and legal validity. Contact Building Control in your borough before work begins.

When Do You Need Building Regulations Approval?

• Structural changes – Taking out load-bearing walls, chimney breasts, or creating new door/window openings typically requires Part A compliance. A structural engineer’s drawings might be needed.
• Bathrooms & plumbing – Adding a bathroom or relocating drains must meet Part H (drainage) and Part F (ventilation).
• Electrical – Rewiring or circuit additions in kitchens/bathrooms have to follow Part P (Electrical Safety). A registered electrician or building control officer must sign off.
• Heating – Installing or replacing boilers, fireplaces, or radiators must align with Parts J (combustion) and L (efficiency). Gas Safe certification is essential for gas boiler tasks.
• Windows/doors – Replacements must satisfy Part L (thermal) and Part K (safety glazing). FENSA/CERTASS typically cover these.
• Garage/basement conversions – Turning these areas into habitable spaces triggers checks on insulation, damp-proofing, fire safety, and ventilation.

In Hillingdon, garage conversions are a regular way of expanding living areas without a formal extension, yet building control approval remains vital.

Additional Considerations

• Fire Safety (Part B) – Homes with open-plan layouts often need additional fire doors or alarms to maintain safe exit routes.
• Ventilation (Part F) – Bathrooms, kitchens, and utility rooms require extractor systems.
• Insulation & Efficiency (Part L) – Major renovations typically incorporate updated insulation for walls, roofs, or windows.
• Soundproofing (Part E) – Creating new flats or converting existing spaces for living demands meeting acoustic insulation requirements.

Either file a Full Plans application (for pre-approval) or use a Building Notice if more straightforward. A completion certificate is issued upon satisfactory final inspection.

Do I Need Planning Permission?

Planning permission is distinct from Building Regulations. Generally, pure interior overhauls do not require consent, unless:

• Listed buildings – Any works touching a listed home’s essential character (inside or out) call for Listed Building Consent.
• Exterior alterations – Adding new windows, re-roofing, or changing cladding might need permission, especially in conservation areas.
• Change of use – Splitting a house into flats or shifting from residential to commercial usage.
• Extensions or loft conversions – Though internal changes rarely need planning, expanding outward or upward typically does.

Some pockets of Hillingdon, particularly in older wards like Uxbridge or Ickenham, impose extra guidelines, so verifying with the council is prudent.

For standard interior improvements—upgrading kitchens/bathrooms, redecorating, or rearranging non-load-bearing partitions—planning permission usually isn’t required. Nonetheless, verifying with your local planning authority if unsure is best.

How to Find the Right Professionals

Selecting dependable, skilled contractors is key to a problem-free renovation. While a few substandard operators circulate, plenty of reputable firms excel in comprehensive refurbishments. TrustMark and the Federation of Master Builders endorse accredited trades, while TrustedBuilders confirms finances, accreditations, and references to match you with appropriate specialists.

Depending on your background, you may hire individual trades yourself or engage a main contractor to oversee everything. A principal contractor simplifies communication, whereas dividing tasks might save some costs but demands extra coordination on your part.

Hillingdon residents often rely on local community recommendations to locate builders who know typical mid-20th-century houses, smoothing the quote process.

Checklist for Home Renovation

1. Precisely define your project scope
2. Investigate financing or loan options
3. Draft a budget, including contingency
4. Determine relevant Building Regulations
5. Check if you need planning permission
6. Obtain multiple quotes (at least three)
7. Validate references, credit, and accreditations
8. Hire trustworthy, accredited trades
9. Agree on a workable timeline
10. Maintain regular communication with your contractor(s)

Regardless of how you structure the work, comparing several quotes helps you gauge both value and reliability. TrustedBuilders offers a route to contractors who provide fair pricing and verifiable track records, easing the refurbishment process.