Interior, Exterior, or Both

When calculating possible expenses, it helps to keep interior and exterior renovations separate at first, then see how combining them might influence your overall budget.

Interior refurbishment

A full interior refurbishment involves more than new paint or swapping a few fittings. It generally covers all flooring, walls, ceilings, plus the renovation of kitchens, bathrooms, plumbing, wiring, and more. Many properties in Barnet—whether Edwardian or 1930s semis—can benefit from internal updates that modernise layouts and utilities.

Typical Costs

Industry statistics suggest that a smaller, simpler interior upgrade might land close to £650 per m², while higher-end projects could exceed £2,000 per m². A ballpark median is around £1,100 per m². These rates include labour, materials, and overheads, though the ultimate figure varies by project scope and finishes.

Exterior renovation

Exterior works range from modest updates to major structural repairs or aesthetic improvements, such as:

• Adjusting drainage or guttering
• Boosting insulation
• Repointing or rendering walls
• Changing roof coverings
• Putting in new windows or doors

Cost Indicators

Standard external renovations often fall between £400 and £700 per m² of wall surface. Straightforward tasks might come in near £250 per m² if minimal materials are needed, while more intricate or upscale approaches can push past £700–£1,200 per m².

In Barnet, older brick facades often require careful repointing to maintain their original character, especially in conservation areas like those near High Barnet.

Both interior and exterior

Working on the interior and exterior in tandem typically multiplies costs, starting from around £1,500 per m² for smaller projects and rising to £3,500 per m² where details are complex. Even so, it is generally cheaper than building new, as existing foundations and structural components remain. Industry data shows an average of roughly £2,600 per m² for new builds in the UK, giving a reference point against which a large-scale renovation can be compared.

Complete Home Renovation in Barnet

If you are renovating a home in Barnet, you have likely seen how diverse the local property market is, from period residences in places like High Barnet and East Barnet to more modern estates near the North Circular. 

One of the main attractions of this North London borough is the ample space many properties offer, sometimes with substantial gardens or lofts ripe for conversion. This flexibility allows you to explore creative changes, such as rear extensions or open-plan living areas, without feeling too cramped. Homeowners in Barnet frequently upgrade lofts into extra bedrooms, an ever-popular choice that can add both space and value.

Local Renovation Costs

When it comes to local renovation costs, Barnet typically falls into a moderate-to-high bracket compared with other Greater London boroughs. While labour rates here may not be as high as central London, the area’s popularity and property values push quotations above the national average. If you plan to extend or alter the exterior in a more historically sensitive part of Barnet, be sure to consult the planning department early. Barnet Council often puts stricter limits on the facade if you are in or near a conservation area.

Typical projects

Besides external modifications, many families in Barnet invest heavily in kitchen expansions or new en-suite bathrooms, making day-to-day life more convenient. If you want to maintain or attain a more traditional look, you might replicate original timber sash windows, common in older Barnet homes, but factor in the higher cost for bespoke joinery.

 Another frequent upgrade is improved insulation—ideal for older builds that might be drafty in colder months. 

Regardless of the type of refurbishment, be prepared to find the odd surprise, like outdated wiring or older pipework. However, if carefully planned and budgeted, a complete renovation can significantly raise a Barnet property’s sale price and deliver a home fit for modern standards while preserving the borough’s characteristic charm.

What Drives the Cost in a Complete Renovation?

Even though per-square-metre guidelines are a decent starting reference, costs can vary hugely depending on these factors:

1. Property size
   The greater the area, the more labour, materials, and time are required, although larger builds may achieve minor economies of scale.
2. Complexity
   A high number of wet rooms, complex layouts, or integrated technology all push costs up. Straightforward rectangular designs or standard ceilings/walls often hold them down.
3. Bathrooms
   Due to plumbing, tiling, and fixtures, bathrooms are regularly the priciest parts of a home renovation. A total bathroom overhaul can lie between £20,000 and £32,000, as per trade organisations.
4. Structural alterations
   Adjusting a property’s main load-bearing elements escalates costs, as structural engineers and planning permission might become essential.
5. Material quality
   Finishes range widely in price. There is a big gap between generic tile choices and high-end stone or custom items.
6. Contractor selection
   Getting quotes from multiple reputable builders and verifying credentials is key. A cheap quote can disguise hidden charges or corner-cutting, so always compare thoroughly.

In Barnet, going for mid-range but durable materials often aligns well with the borough’s typical property values and buyer expectations.

What’s Included in the Contractor’s Quote?

Usually, the contractor’s formal estimate includes the main tasks needed for the renovation, as well as general building materials. But it is vital to confirm details early on:

• Labour: For structural, electrical, plumbing, and finishing trades.
• Coordination: Overall management or coordination of trades might be in the main bid.
• Raw materials: Timber, plasterboard, piping, cables, adhesives.

Homeowners normally handle “finishing materials” personally, or they appear under an allowance:

• Kitchen and bathroom suites: You could pick out the designs and pay directly, while your contractor installs them.
• Flooring and tiling: Costs vary from low-cost laminates to premium hardwood or imported tiles, each with different labour intensities.
• Fixtures and fittings: Sinks, taps, showers, and decorative lighting are often sourced separately.

A number of long-standing contractors in Barnet have specialised in upgrading 1920s–1930s semis, so searching locally can streamline the building process.

Cost Breakdown for Individual Elements

As an example, take a 230 m² detached home that underwent a thorough interior and exterior overhaul. The contractor’s quote (labour + essential materials) looked like this:

• Replace 20 windows + delivery: £27,000
• Cut new window opening: £3,200
• New cladding + insulation: £33,000
• Roof rework: £21,500
• Drainage work: £12,800
• Main bathroom, excluding tiles/fixtures (plumber included): £19,000
• WC room 1 (plumber included): £3,600
• WC room 2 (plumber included): £3,600
• Utility area with plumbing: £10,800
• All-new plumbing: £18,400
• External door and patio door: £4,800
• Balanced ventilation: £9,600
• Internal surfaces (floors, walls, ceilings): £41,600
• Internal doors: £6,000
• Architraves, linings, transitions: £2,000
• Electrics for entire house: £29,600
• Single attached garage: £14,400
• Waste management: £4,800
• Demolition, site setup, scaffolding: £24,000
• Interior designer: £6,000
• Architect: £4,000

Contractor sum: £300,800

Homeowner’s separate purchases:

• Tiles (for bathroom, WC, utility, hallway): £4,800
• Bathroom fixtures (1 bath + 2 WC): £6,400
• Kitchen units: £24,000
• Additional flooring: £10,000

Subtotal (Owner items): £45,200

Grand Total: £346,000

At 230 m², this finished around £1,500 per m²—somewhat below typical figures for combined interior-exterior jobs.

Building Regulations for a Complete Home Renovation (UK)

Large-scale improvements must conform to Building Regulations, ensuring building integrity, electrical safety, and energy efficiency. To comply, contact Building Control at your local council:

When Do You Need Building Regulations Approval?

• Structural modifications: Removing supporting walls or inserting new beams.
• Wet rooms and plumbing: Adding or relocating bathrooms, WCs, or kitchens.
• Electrical works: Rewiring or adding circuits, particularly in ‘special locations’ like bathrooms.
• Heating upgrades: Fitting or replacing boilers, fireplaces, or flues, checked by qualified engineers.
• Windows/doors: Replacements must satisfy safety and thermal standards.

Additional Considerations

• Fire safety (Part B): Fire doors, alarms, or sprinklers might be necessary in certain designs.
• Ventilation (Part F): Ensures air circulation is adequate in kitchens, bathrooms, utility areas.
• Insulation & efficiency (Part L): Demands improved insulation if feasible in a major refurbishment.
• Soundproofing (Part E): Dividing a home or building flats triggers requirements for acoustic separation.

Once works pass final inspection, you receive a completion certificate stating compliance.

Do I Need Planning Permission?

Planning consent is separate from Building Regulations. Generally, internal changes alone require no planning permission unless:

• Listed building: Even internal alterations to a listed property need Listed Building Consent.
• External appearance: Adding windows, altering roof shapes, or re-cladding can trigger permission.
• Change of use: Converting from a single home to flats or turning residential space commercial.
• Extensions or loft conversions: Large expansions or roof modifications might exceed Permitted Development allowances.

Certain sectors of Barnet are conservation areas—like parts of Hampstead Garden Suburb—where even modest external tweaks may need official permission.

How to Find the Right Professionals

Selecting dependable, skilled individuals is vital to ensure that the renovation proceeds smoothly and meets quality standards.

• Accreditations: Look for contractors with membership in reputable bodies, e.g., TrustMark or the Federation of Master Builders.
• References & track records: Request evidence of past similar projects and confirm the firm’s creditworthiness.
• Project management approach: Hiring a main contractor to oversee everything is typical, although you could supervise separate trades if you have adequate knowledge and time.

In Barnet, word-of-mouth can be powerful—local forums or community groups may help identify established tradespeople.

Checklist for home renovation

1. Plan what you want to achieve, researching ideas thoroughly.
2. Evaluate financing or loan possibilities.
3. Budget realistically with a contingency buffer.
4. Ascertain whether Building Regulations apply.
5. Check if planning permission is needed.
6. Obtain three or more quotes.
7. Verify references and accreditations.
8. Secure reliable tradespeople or a seasoned main contractor.
9. Agree on a workable timeline.
10. Maintain open communication to keep everything on track.

By adhering to these steps, you set the stage for a smoother, more controlled renovation. Having multiple quotes, checking references, and carefully planning each phase minimise financial and logistical mishaps.

A comprehensive renovation project in Barnet can modernise your living space while elevating the overall property value. With a measured plan, reputable contractors, and clear knowledge of local regulations, you will be able to carry out extensive works in line with 2025 guidelines. Good luck with your Barnet home transformation!