By the Golbik GBS team · Blog

Choosing the right builder matters more than almost any other decision in a renovation. A good builder keeps the project safe, on schedule and within budget; the wrong one can cost far more than the price difference between quotes. This checklist covers what to check before you sign.

Key takeaways

• Check the company, its insurance and independent reviews before inviting quotes.
• Ask for registrations that cover specialist work: NICEIC or similar for electrics, Gas Safe for gas.
• Compare itemised written quotes based on the same specification, not just the total.
• Agree a written contract and stage payments linked to completed work, not large sums upfront.
• Be wary of cash-only deals, pressure to decide quickly and quotes far below the others.

Before You Ask for Quotes

• Check the company – a limited company can be looked up on Companies House to confirm its registered address, directors and how long it has traded.
• Read independent reviews – look for a track record on platforms such as Checkatrade and Google, ideally with recent jobs similar to yours.
• Ask about insurance – public liability insurance as a minimum, and ask to see the certificate.
• Check registrations – NICEIC or a similar scheme for electrical work, Gas Safe for any gas work.
• Ask about waste – builders removing waste should hold a waste carrier registration with the Environment Agency.

Questions to Ask Every Builder

Comparing Quotes

Give every builder the same drawings and specification. Compare itemised quotes line by line, check what is described as a provisional sum, and ask about anything that appears in one quote but not another. The cheapest total is often the one with the most exclusions. Our full refurbishment guide explains what a complete scope of work usually includes.

Contracts and Payments

• Use a written contract; for larger domestic projects, standard forms such as the JCT contract for homeowners are widely used.
• Agree stage payments linked to completed work, with a small retention until snagging is finished.
• Record changes in writing, with the cost agreed before the work is done.
• Make sure approvals are in place: planning or permitted development, Party Wall agreements and Building Regulations. See planning rules by borough.

Red Flags

• Cash-only payment or a discount for paying without a receipt.
• Pressure to sign the same day or to pay most of the price upfront.
• No business address, company details or written quote.
• A price far below the other quotes with little detail.
• Reluctance to provide insurance details, registrations or references.

Frequently Asked Questions

How many quotes should I get?

Three is a sensible number for most projects. Give every builder the same drawings and specification so the quotes can be compared like for like.

How much deposit should I pay a builder?

Avoid paying a large sum upfront. A modest deposit for materials or scheduling may be reasonable, with the rest paid in stages as agreed parts of the work are completed.

How can I check an electrician or gas engineer?

Electricians registered with a competent person scheme such as NICEIC can be checked on the scheme’s register, and gas engineers on the Gas Safe Register. Ask to see the relevant card or registration number.

What are my rights if I sign a contract at home?

For contracts agreed at your home, consumers usually have a 14-day cancellation period. Under the Consumer Rights Act 2015, services must also be carried out with reasonable care and skill.

How We Approach Your Project

Golbik GBS Ltd is a registered company (Companies House 12142749), has been on Checkatrade since 2016 with a rating of 9.8 out of 10 from 130 reviews, and our electrical work is carried out as a NICEIC Domestic Installer. Read our customer recommendations, explore our full refurbishment and extension services, or request a quote.

Related Guides

• Full House Refurbishment in London: Stages, Permissions and Timeline
• Loft Conversion Types for London Homes
• Side-Return, Rear or Wraparound Extension?
• Planning a Kitchen Renovation in a London Home
• Bathroom Renovation in London: Wet Rooms, Waterproofing and Safety Zones
• Does Your London Home Need Rewiring?
• Upgrading Heating and Plumbing in an Older London Home
• Party Wall Agreements in London: A Homeowner’s Guide
• Do You Need Planning Permission? Rules by London Borough
• Extending a 1930s Semi in Sutton, Wallington and Mitcham
• Consumer Unit (Fuse Box) Upgrades Explained
• Renovating a Victorian Terrace in South West London

By the Golbik GBS team · Blog

Victorian terraces line the streets of Clapham, Fulham, Wimbledon and much of South West London. They are solid, well-proportioned homes, but they were built with materials and methods very different from today’s. Renovating one well means understanding how it was built. For the overall sequence of a project, see our full house refurbishment guide.

Key takeaways

• Victorian terraces have solid brick walls, suspended timber floors and lime-based materials, which behave differently from modern houses.
• Damp is often caused by cement render, blocked air bricks or high ground levels rather than a failed damp-proof course.
• Original features such as cornices, ceiling roses and fireplaces can usually be restored rather than replaced.
• Old wiring and lead or iron pipework should be renewed while floors and walls are open.
• Conservation area rules in parts of Clapham, Fulham and Wimbledon affect windows, roofs and front elevations.

How Victorian Terraces Were Built

Common Problems to Look For

• Damp – often caused by cement render or pointing, blocked air bricks, leaking gutters or garden levels above the floor, rather than a failed damp-proof course.
• Timber decay in floor joists and window frames where moisture has been trapped.
• Movement – London clay and nearby trees can cause cracking, which should be assessed before redecorating.
• Old services – outdated wiring and lead or iron pipework. See our guides to rewiring and heating and plumbing upgrades.
• Poor insulation – solid walls and single-glazed sashes lose heat; internal wall insulation must be breathable to avoid condensation.

Keeping the Character

Original cornices, ceiling roses, picture rails, fireplaces and sash windows are a large part of what buyers value in a period house. Damaged plasterwork can usually be repaired or re-run, and sashes can be refurbished and draught-proofed.

Clapham, Fulham and Wimbledon Compared

• Clapham – Victorian and Edwardian terraces split between Lambeth and Wandsworth, with conservation areas around the Common. See our Clapham guide and loft conversions in Clapham.
• Fulham – long late-Victorian terraces, many converted into flats, and many conservation areas. See our Fulham guide and plumbing in Fulham.
• Wimbledon – Victorian and Edwardian terraces around South Wimbledon and the Colliers Wood borders, in the London Borough of Merton. Nearby, see our Mitcham guide.

The Right Order of Works

1. Survey, including damp, structure and services.
2. Fix the building fabric: roof, gutters, external walls and ground levels.
3. Structural work and any extension.
4. First fix of electrics, plumbing and heating.
5. Plastering, with lime where walls need to breathe.
6. Kitchens, bathrooms, joinery and restored features.
7. Decoration and final checks.

Check the planning position early in our guide to planning rules by London borough.

Frequently Asked Questions

How are Victorian terraces different from modern houses?

They usually have solid brick walls without a cavity, lime mortar and plaster, suspended timber ground floors and a rear outrigger. These materials need to breathe, so modern impermeable finishes can trap moisture.

Should I use lime or gypsum plaster?

On solid walls that suffer from damp, breathable lime-based plaster is often the better choice. Gypsum plaster is suitable on dry internal walls and new partitions. A survey of each wall helps decide.

Can I replace sash windows in a conservation area?

Often only like for like. In many conservation areas, replacing timber sash windows with a different style or material needs planning permission, so repair or draught-proofing is usually the first option.

What is a butterfly roof?

Many inner London terraces have a V-shaped roof hidden behind a front parapet, known as a London or butterfly roof. Converting it usually means a mansard, which needs planning permission.

Planning a Victorian House Renovation?

Golbik GBS carries out full refurbishments of period houses and flats across London. See our Clapham and Fulham area guides, or get in touch to arrange a survey.

Related Guides

• Full House Refurbishment in London: Stages, Permissions and Timeline
• Loft Conversion Types for London Homes
• Side-Return, Rear or Wraparound Extension?
• Planning a Kitchen Renovation in a London Home
• Bathroom Renovation in London: Wet Rooms, Waterproofing and Safety Zones
• Does Your London Home Need Rewiring?
• Upgrading Heating and Plumbing in an Older London Home
• Party Wall Agreements in London: A Homeowner’s Guide
• Do You Need Planning Permission? Rules by London Borough
• Extending a 1930s Semi in Sutton, Wallington and Mitcham
• Consumer Unit (Fuse Box) Upgrades Explained
• How to Choose a Builder in London

By the Golbik GBS team · Blog

A bathroom is a small room with a lot going on behind the walls: water, waste, electrics and ventilation all have to be right before the first tile goes on. This guide covers the technical decisions that make a bathroom renovation in a London home last, from wet rooms and waterproofing to electrical safety zones and water pressure.

Key takeaways

• Good waterproofing behind the tiles matters more than the tiles themselves, especially in wet rooms.
• Bathrooms are divided into electrical zones; lights and fittings must have the right IP rating for each zone.
• Bathroom circuits need 30mA RCD protection under the wiring regulations.
• Building Regulations require mechanical extraction of at least 15 litres per second in bathrooms.
• Older London homes often have low water pressure, which affects the choice of shower and boiler.

Wet Room, Walk-In Shower or Shower Tray?

In many London flats and terraces, floors are timber joists, which move slightly. Wet rooms are still possible, but the floor needs to be stiffened and a purpose-made former or tray installed beneath the tiles.

Waterproofing: What Goes Behind the Tiles

• Tanking membrane: a liquid or sheet membrane applied to walls and floors in wet areas to stop water reaching the structure.
• Suitable boards: cement-based or waterproof boards rather than standard plasterboard around showers and baths.
• Sealed junctions: tape at corners, joints and around pipes and drains.
• Grout and silicone: good-quality materials that are maintained over time.

Poor waterproofing is the most common cause of leaks into ceilings below, so it is not the place to save money.

Electrical Safety Zones and IP Ratings

The wiring regulations divide bathrooms into zones based on how close a fitting is to water:

All bathroom circuits must be protected by a 30mA RCD. Shaver sockets must be the dedicated, isolated type. Work in bathrooms should be carried out and certified by a registered electrician, as provided by our electrical services.

Ventilation

Building Regulations require mechanical extraction in bathrooms of at least 15 litres per second. A fan with an overrun timer or humidity sensor removes moisture after showering and protects paint, grout and ceilings from mould, a common problem in older London houses with small windows.

Water Pressure in Older London Homes

Many older properties have low water pressure, especially on upper floors or with old gravity-fed systems. Options include a mains-pressure unvented cylinder, a shower pump on a gravity system or a combi boiler where mains flow is good. Hard London water also means scale protection is worth considering. Our plumbing team can test pressure and flow before you choose a shower.

Bathrooms as Part of a Bigger Project

A new en-suite is a popular part of a loft conversion, and bathrooms are often renovated alongside a new kitchen or as part of a full refurbishment.

We renovate bathrooms throughout London, including Clapham, Fulham, Chelsea, Hammersmith, Dulwich and Mitcham.

Frequently Asked Questions

Is a wet room a good idea in a London flat?

It can be, provided the floor can be laid to a fall towards the drain and the whole room is fully waterproofed. In upper-floor flats, timber floors need careful preparation, and the lease may require the freeholder’s consent for changes to waste pipes.

What IP rating do bathroom lights need?

Fittings inside the bath or shower tray (zone 0) need at least IPX7. Fittings in zone 1, directly above the bath or shower up to 2.25 metres, and in zone 2 around it typically need at least IPX4. A registered electrician will confirm the correct rating for each position.

Do I need an extractor fan in my bathroom?

Yes, for a new or renovated bathroom. Building Regulations guidance sets a minimum intermittent extract rate of 15 litres per second. Fans linked to the light or a humidity sensor help prevent condensation and mould.

Can I add a bathroom in my loft?

Usually, yes. A loft bathroom needs a waste route to the soil stack, adequate water pressure on the top floor and enough head height over the shower and toilet. It is often planned as part of a loft conversion.

Planning a New Bathroom?

Golbik GBS renovates bathrooms, en-suites and wet rooms across London, handling plumbing, electrics, waterproofing, tiling and finishing. Find out more about our bathroom renovation service in London or get in touch to discuss your project.

Related Guides

• Full House Refurbishment in London: Stages, Permissions and Timeline
• Loft Conversion Types for London Homes
• Side-Return, Rear or Wraparound Extension?
• Planning a Kitchen Renovation in a London Home
• Does Your London Home Need Rewiring?
• Upgrading Heating and Plumbing in an Older London Home
• Party Wall Agreements in London: A Homeowner’s Guide
• Do You Need Planning Permission? Rules by London Borough
• Extending a 1930s Semi in Sutton, Wallington and Mitcham
• Consumer Unit (Fuse Box) Upgrades Explained
• Renovating a Victorian Terrace in South West London
• How to Choose a Builder in London

By the Golbik GBS team · Blog

A kitchen renovation involves more trades than any other room: plumbers, electricians, joiners, plasterers, tilers and often a gas engineer and a structural engineer. In London homes, where kitchens are often narrow or tucked into a rear outrigger, careful planning makes the space work much harder. This guide walks through how to plan a kitchen renovation from layout to final fix.

Key takeaways

• Choose the layout first: it determines where pipes, drains, sockets and extraction must go.
• Electrics, plumbing and ventilation are installed before plastering, so appliance positions must be fixed early.
• Building Regulations require kitchen extraction and cover new electrical circuits, gas work and structural changes.
• Bespoke cabinets and worktops have lead times, so order them before the strip-out starts.
• Worktops are templated only after the base units are fitted.

Choosing the Right Layout

Many London kitchens are transformed by a side-return or rear extension, which turns a narrow galley into an open-plan kitchen-diner. If you are considering one, design the kitchen and the extension together.

Services: Plumbing, Electrics, Gas and Ventilation

Plumbing and drainage

Sinks, dishwashers and washing machines need water supplies and waste pipes with enough fall to the drain. Moving the sink a long way from the existing drain can mean pumps or new drainage runs. Our plumbing service covers these alterations.

Electrics

Modern kitchens need many more sockets and dedicated circuits for ovens, hobs and other appliances than older houses were built with. New circuits are notifiable work, carried out and certified by a registered electrician. See our electrical services.

Gas

Any work on gas hobs, cookers or pipework must be carried out by a Gas Safe registered engineer.

Ventilation

Building Regulations require mechanical extraction in kitchens: at least 30 litres per second for a cooker hood, or 60 litres per second for a fan elsewhere in the room. Ducting the hood to the outside wall is the most effective solution.

The Order of Works

1. Survey, design and ordering: final layout, appliances and finishes; order cabinets and long-lead items.
2. Strip-out: remove the old kitchen, flooring and damaged plaster.
3. Structural work: remove or open up walls with new beams where required.
4. First fix: new pipework, drainage, cabling, gas and extraction ducting.
5. Plastering and flooring preparation: new or repaired walls and ceilings, level floors.
6. Installation: fit base and wall units, then template the worktops.
7. Worktops, splashbacks and tiling.
8. Second fix: sink, taps, appliances, sockets and lighting connected.
9. Decoration and finishing touches.

Changing the layout after first fix is the most common cause of delay and extra cost, so it is worth taking time over the design.

Kitchens in Period Homes and Flats

Older London houses often have uneven walls and floors, which need extra preparation before units can be fitted. In flats, check the lease before moving the kitchen, as freeholders often restrict placing kitchens above bedrooms in the flat below, and changes to waste pipes may need consent.

If you are renovating in one of our core areas, see our guides to Clapham, Fulham, Chelsea, Hammersmith, Dulwich and Mitcham.

A kitchen is often part of a larger project such as a full refurbishment, and many clients renovate their bathrooms at the same time.

Frequently Asked Questions

How long does a kitchen renovation take?

Once materials are on site, the installation of a typical kitchen takes a few weeks, from strip-out to final fix. Bespoke cabinetry and stone worktops add lead time beforehand, and structural work such as removing a wall adds time on site.

Do I need Building Regulations approval for a new kitchen?

Replacing units like for like does not usually need approval. New electrical circuits, gas appliances, drainage changes, removing a load-bearing wall and new extraction all fall under Building Regulations, and are signed off by registered installers or building control.

How powerful should a kitchen extractor be?

Building Regulations guidance sets a minimum extract rate of 30 litres per second for a cooker hood over the hob, or 60 litres per second for an extract fan positioned elsewhere in the kitchen. Ducting to the outside is far more effective than a recirculating hood.

Can I move my kitchen to another room?

Often, yes, but it depends on getting a waste pipe to the soil stack or drain with enough fall, and on ventilation and gas routes. This should be checked at the survey stage.

Planning a New Kitchen?

Golbik GBS renovates and installs kitchens across London, coordinating plumbing, electrics, structural work, cabinetry, worktops, tiling and decoration. See our kitchen renovation service in London or contact us to discuss your kitchen.

Related Guides

• Full House Refurbishment in London: Stages, Permissions and Timeline
• Loft Conversion Types for London Homes
• Side-Return, Rear or Wraparound Extension?
• Bathroom Renovation in London: Wet Rooms, Waterproofing and Safety Zones
• Does Your London Home Need Rewiring?
• Upgrading Heating and Plumbing in an Older London Home
• Party Wall Agreements in London: A Homeowner’s Guide
• Do You Need Planning Permission? Rules by London Borough
• Extending a 1930s Semi in Sutton, Wallington and Mitcham
• Consumer Unit (Fuse Box) Upgrades Explained
• Renovating a Victorian Terrace in South West London
• How to Choose a Builder in London

By the Golbik GBS team · Blog

A full house refurbishment is the most complete kind of renovation: the property is stripped back, its services renewed and its layout improved before everything is finished again. In London, where many homes are Victorian or Edwardian and often sit in conservation areas or leasehold buildings, good planning makes the difference between a smooth project and an expensive one. This guide explains how a full refurbishment in London works, step by step.

Key takeaways

• A full refurbishment usually follows eight stages, from survey and design to snagging and sign-off.
• Internal work in a house rarely needs planning permission, but Building Regulations, the Party Wall Act and, for flats, the freeholder’s consent often apply.
• Electrics, plumbing and heating are renewed during “first fix”, before plastering, so decisions on layout, lighting and kitchens must be made early.
• As a rough guide, flats take two to three months on site and terraced houses four to six months.
• Keep a 10 to 20 percent contingency and collect all compliance certificates at the end.

What Is a Full House Refurbishment?

A full refurbishment covers the whole property rather than a single room. It typically includes stripping out old finishes, structural alterations such as removing walls, renewing the electrical installation, plumbing and heating, re-plastering, new kitchens and bathrooms, flooring, joinery and complete redecoration. It differs from a cosmetic renovation, which refreshes surfaces but leaves the services and layout largely as they are.

For many London homeowners it is the moment to fix everything at once: outdated wiring, inefficient heating, an awkward layout and tired finishes. Doing it in one coordinated project avoids opening up walls and floors twice. You can see what this involves in practice on our full refurbishment service page.

The 8 Stages of a Full Refurbishment

1. Survey and brief

Every project starts with a survey of the property and a clear brief: what you want to change, how you will use each room, your budget and your timescale. For older homes, this is also when hidden issues such as damp, movement or failing services are identified.

2. Design and specification

Layouts, structural changes, lighting, sockets, kitchens, bathrooms and finishes are agreed and written into a specification. The more decisions made at this stage, the more accurate the quote and the fewer costly changes later.

3. Permissions, notices and approvals

Depending on the work, this can include Building Regulations approval, Party Wall notices to neighbours, a licence to alter from your freeholder and, where relevant, planning permission or listed building consent. The table in the next section shows what usually applies.

4. Strip-out and structural work

Old kitchens, bathrooms, flooring and damaged plaster are removed. For homes built before 2000, an asbestos refurbishment survey before strip-out is strongly recommended. Structural alterations, such as removing load-bearing walls with new steel beams, are carried out to an engineer’s design.

5. First fix: electrics, plumbing and heating

With walls and floors open, new cables, pipework, drainage and heating are installed. This is the stage when the electrical installation is rewired and the plumbing and heating system renewed, so positions for sockets, lights, radiators and appliances need to be final.

6. Plastering, insulation and joinery

Walls and ceilings are plastered or boarded, insulation and soundproofing added where needed, and joinery such as door linings, skirting and staircases repaired or replaced.

7. Second fix, kitchens and bathrooms

Sockets, switches, lights, radiators and sanitaryware are connected, and the kitchen and bathrooms are installed, tiled and finished.

8. Decoration, snagging and sign-off

Flooring and decoration complete the work. A final walk-through produces a snagging list of small defects to be put right, and the compliance certificates are handed over.

Which Permissions and Certificates Do You Need?

Permissions depend on what you change and on the type of property. This overview covers the most common situations in London:

If the refurbishment also adds space, see our guides to house extensions and loft conversions. For domestic projects, the Construction (Design and Management) Regulations 2015 normally pass the client’s health and safety duties to the contractor.

How Long Does a Full Refurbishment Take?

The time on site depends on the size of the property, the amount of structural work and how quickly decisions are made. As a rough guide:

• One- or two-bedroom flat: around two to three months on site.
• Three- or four-bedroom terraced house: around four to six months on site.
• With an extension or loft conversion: add several months, depending on the design.

Before work starts, allow time for design, Party Wall agreements, freeholder consent and the lead time of bespoke items. Changes to the specification once work has started are the most common cause of delay.

Refurbishing a Period Property in London

Most London refurbishments involve Victorian or Edwardian houses, or flats converted from them. These buildings bring particular considerations: original features worth keeping, older wiring and lead or iron pipework, suspended timber floors, lime plaster and, in many streets, conservation area rules on windows and front elevations.

Local rules vary by borough. Our area guides explain what to expect in Clapham, Fulham, Chelsea, Hammersmith, Dulwich and Mitcham.

Budgeting and Living Arrangements

• Fix the specification first. A detailed specification gives comparable quotes and fewer surprises.
• Keep a contingency. Many professionals recommend 10 to 20 percent of the build cost, towards the upper end for older homes.
• Check the VAT position. Renovation work is normally standard-rated, but a reduced 5 percent rate can apply to homes that have been empty for at least two years. Confirm with HMRC or an accountant.
• Plan where you will live. For a full refurbishment, moving out is usually faster, cheaper and far more comfortable than living on site.
• Use one contractor to coordinate. A single point of contact for all trades reduces gaps between stages and responsibility disputes.

Frequently Asked Questions

How long does a full house refurbishment take in London?

As a rough guide, a full refurbishment of a two-bedroom flat often takes around two to three months on site, and a three- or four-bedroom terraced house around four to six months. Design, approvals and lead times for items such as kitchens and windows come on top, and extensions or loft conversions add further time.

Do I need planning permission for a full refurbishment?

Not usually for internal work in a house. Planning permission is typically needed for extensions beyond permitted development, external changes in conservation areas, changes to flats, and any work to listed buildings, which also needs listed building consent. Building Regulations apply to most structural, electrical, drainage and heating work either way.

Can I live in my home during a full refurbishment?

It is possible for some phased projects, but for a genuine full refurbishment most people move out. The kitchen, bathroom, heating and power are disconnected for long periods, and the work moves faster and costs less when the trades have the whole property.

What certificates should I receive at the end?

Typically a Building Regulations completion certificate for notifiable work, an Electrical Installation Certificate for new wiring, a Gas Safe certificate for gas and boiler work, and FENSA or equivalent certificates for replacement windows. Keep them safe, as buyers and their solicitors will ask for them.

How much contingency should I allow?

Many professionals recommend keeping 10 to 20 percent of the build cost in reserve, towards the upper end for older London properties, where hidden issues such as damp, rotten joists or outdated wiring are common.

Planning a Full Refurbishment?

Golbik GBS manages full refurbishments of houses and flats across London, coordinating every trade from strip-out to final decoration. Find out more about our full refurbishment service in London or get in touch to arrange a consultation.

Related Guides

• Loft Conversion Types for London Homes
• Side-Return, Rear or Wraparound Extension?
• Planning a Kitchen Renovation in a London Home
• Bathroom Renovation in London: Wet Rooms, Waterproofing and Safety Zones
• Does Your London Home Need Rewiring?
• Upgrading Heating and Plumbing in an Older London Home
• Party Wall Agreements in London: A Homeowner’s Guide
• Do You Need Planning Permission? Rules by London Borough
• Extending a 1930s Semi in Sutton, Wallington and Mitcham
• Consumer Unit (Fuse Box) Upgrades Explained
• Renovating a Victorian Terrace in South West London
• How to Choose a Builder in London