Quick answer: The most reliable way to budget for a kitchen renovation is to divide your spending across three separate buckets, the kitchen itself, appliances, and the surrounding building works, then apply a contingency of 15–20% to the combined total. Most overspends happen in the third bucket, not the cabinetry, and most of them are entirely predictable if you account for them from the start.

Kitchen budgets rarely stay still. You settle on a figure, receive a quote that looks solid, and then find the total creeping as the project develops, not dramatically, but enough to cause genuine stress. In most cases this isn’t the kitchen supplier’s fault. It’s a planning structure problem: most homeowners budget the whole renovation as a single line item, without separating out the building and services work that almost always runs alongside it. This guide sets out a practical framework for budgeting accurately, including the specific costs that reliably surface late – and how to plan for them before they arrive.

The Three-Bucket Method, and Why It Works

The most common kitchen budgeting mistake is treating the project as one cost. In practice, there are three distinct categories of spend, and they behave quite differently.

Bucket 1 – The kitchen itself. Cabinetry, worktops, handles, sinks and taps. This is the number you receive from a showroom quote, and it’s typically the most predictable of the three.

Bucket 2 – Appliances. Oven, hob, extractor, fridge-freezer, dishwasher, and any wine cooling or warming drawers. Sometimes included in a kitchen quote; often not. A basic integrated set costs £2,000–£4,000. A considered selection of Siemens, Neff or Bosch built-in appliances for a mid-range German kitchen typically runs £6,000–£12,000, and is frequently budgeted as an afterthought.

Bucket 3 – Works around the kitchen. Gas engineer, electrician, plumber, plasterer, tiler, flooring contractor, waste removal, and any building control fees where structural work is involved. This is the bucket that expands.

The table below shows how these three buckets typically split across a £40,000 German kitchen renovation.

For a worked example of how these figures break down in detail, see where the money actually goes in a £30,000 kitchen. And for the broader context on what drives German kitchen pricing at each tier, our full guide to German kitchen costs in 2026 covers the complete picture.

Why 10% Contingency Isn’t Enough

The standard “add 10%” advice is borrowed from general building work and doesn’t reflect how kitchen renovations actually behave. In a kitchen project, the contingency needs to absorb items that are not random, they follow predictable patterns.

Service relocation is one. Moving a gas point, adding a dedicated socket circuit, or rerouting a waste outlet each typically cost £300–£800 in isolation. Combined, they regularly reach £1,500–£2,500 on a mid-size project.

Making-good after the old kitchen comes out is another. Removing fitted units almost always exposes uneven wall sections, patches of missing plaster or areas of old adhesive that need full re-skimming before the new kitchen goes in. Plastering a typical kitchen’s walls runs £400–£900.

Worktop upgrades are the third common source. Many clients move from laminate to quartz between design and order sign-off. That single decision can add £1,500–£3,000 on a mid-size kitchen.

A 15% contingency on the combined three-bucket total is realistic for a straightforward renovation. Where any service relocation, gas certification or extension work is involved, 20% is the appropriate figure. On a £40,000 project, that means keeping £6,000–£8,000 in reserve, not the £4,000 that 10% on cabinetry alone would suggest.

The Costs That Arrive Late, and Why They’re Predictable

Some costs are entirely predictable but routinely left off early plans. Others emerge once the old kitchen is out and the wall behind it is visible for the first time. Either way, they tend to arrive when the budget is already committed.

Building control fees. If your renovation involves structural changes or forms part of an extension, local authority approval is likely required. Fees typically run £200–£800 for domestic kitchen work.

Gas Safe certification. Any modification to the gas supply requires a registered engineer and a signed certificate. Budget £100–£250 per visit.

Electrical first-fix. Relocating a kitchen layout almost always means moving socket positions and ceiling light points before plasterboard, the electrician needs to be on site early, not after plastering is done. Budget £500–£1,500 depending on scope.

Flooring transitions. New kitchen flooring rarely meets adjacent rooms at the same height. A transition trim plus any levelling compound adds £100–£400 and is regularly forgotten until the very last day on site.

Research from Which? consistently shows that unexpected costs affect the majority of home renovation projects. A three-bucket budget, written out before you approach a showroom, moves most of these from “unexpected” to “planned for”.

A Budget-Discipline Framework That Actually Works

Knowing the costs is the first step. Keeping control of them as the project progresses is the harder part. Four disciplines that hold kitchen budgets together:

Lock appliance choices before the manufacturing order. Appliances specified after the kitchen enters production are the most common source of late cost creep. Changing the list after sign-off can trigger revision fees and, in some cases, cabinet-size amendments that ripple through the design.

Get written quotes for each trade separately. A single turnkey installation price can look efficient, but separate trade quotes let you compare line by line and identify where estimates have been set loosely.

Set a decision deadline and keep it. Clients who postpone worktop or handle choices past the manufacturing sign-off frequently find themselves upgrading under time pressure, and last-minute changes nearly always carry a premium over the scheduled price.

Track spend against each bucket once work begins. A simple spreadsheet: bucket, budget, committed, remaining – takes ten minutes a week and prevents the slow accumulation of small overruns that adds up to a significant overspend by the end.

Can You Phase a Kitchen Project to Spread the Cost?

Phasing is sometimes possible but more constrained than it first appears. The core cabinetry and worktop installation is difficult to split across time: the trades sequence – plumber in, worktop template taken, worktop fitted, plumber completes – doesn’t offer natural pause points. Breaking it typically leaves the project with services capped off and a kitchen that isn’t usable for months.

Where phasing tends to work: deferring some appliances. Fitting a standard integrated oven now and upgrading to a steam oven in 12 months is feasible, provided the cabinetry and extract are designed around the final spec from the start. Deferring an island addition can also work if the floor and services are roughed in during the main project.

If budget is a genuine constraint, the time to discuss phasing is at the planning stage – not after the quote is agreed and the manufacturing schedule is set.

Common Mistakes to Avoid

• Treating the kitchen showroom quote as the total budget – without accounting separately for appliances and surrounding building works.
• Applying a 10% contingency to cabinetry only – rather than 15–20% on the combined three-bucket total.
• Delaying appliance choices past the manufacturing sign-off – which triggers revision fees and potential cabinet amendments.
• Overlooking building control fees and Gas Safe certification – both are mandatory where they apply and neither can be skipped.
• Not obtaining separate written trade quotes – making it harder to identify where the budget is running loose.
• Planning flooring, lighting and electrical first-fix as afterthoughts – rather than costing them in from the beginning.

Frequently Asked Questions

What’s a good contingency for a kitchen renovation?
15–20% of the combined three-bucket total is realistic for most kitchen renovations. 10% is widely quoted but rarely sufficient once service relocation, making-good and worktop upgrades are factored in. For projects involving gas, drainage or structural work, 20% is the safer figure. On a £40,000 project that means keeping £6,000–£8,000 in reserve – not £4,000.

Why do kitchen prices go up after the original quote?
Most post-quote increases come from the building and services work around the kitchen, not the cabinetry. Service relocation, plastering after the old kitchen is removed, and worktop upgrades are the most common causes. Changing appliances or finishes after the manufacturing order is placed can also trigger revision fees and lead to cabinet-size amendments.

How do I keep a kitchen renovation on budget?
Divide your budget across three separate buckets before setting a total. Lock all material and appliance decisions before the manufacturing order is placed. Get written quotes from each trade separately. Track spend against each bucket weekly once site work begins. The discipline is more effective than simply setting a larger contingency.

What hidden costs catch people out most often?
The most predictable hidden costs are: service relocation (gas point, additional sockets, waste rerouting), making-good walls after the old kitchen is removed, building control fees where applicable, Gas Safe certification, electrical first-fix, and flooring transitions. None of these are unusual – they are avoidable surprises once you know to plan for them from the start.

Can I phase a kitchen project to spread the cost?
Core cabinetry and worktops are difficult to phase because the trades sequence doesn’t allow natural pause points. Deferring some appliances – fitting a standard oven now, upgrading to a better model in 12 months – is feasible if the cabinetry is designed around the final spec. Deferring an island also works if services and flooring are roughed in during the main project.

Is the appliance cost separate from the kitchen showroom quote?
It depends on the supplier. Some include appliances in their headline figure; others price them separately or leave the selection to you. Always clarify this at the outset. A considered built-in appliance selection for a mid-range German kitchen – Siemens, Neff or Bosch – typically adds £6,000–£12,000 on top of cabinetry and worktops, and is worth planning for as its own budget line.

Wherever you are in your kitchen plans, a short conversation with one of our designers can save weeks of second-guessing. Chat with a designer no pressure, no sales pitch, just practical guidance grounded in real installation experience.

Written by Danil Sugakov, Director, Suga Küchen. Last updated 8 May 2026.