How to estimate home renovation Costs (and what most people get wrong)

If you’re thinking about updating your home, whether that’s a full renovation or a single-room refresh, one of the first things you’ll want to understand is what it’s actually going to cost.

It sounds like a simple question. It rarely is.

Most people start with a vague figure in mind, begin looking at sofas and paint colours, and then often realise the number in their head bears very little resemblance to reality. You’re not alone if that happens to you. In fact, in our experience, almost every homeowner underestimates what they’ll need to invest – sometimes by a significant margin.

The good news is that getting to a realistic figure isn’t complicated. It just takes a bit of structure and of course time. This guide walks you through the process step by step, with enough detail to give you genuine confidence in the number you arrive at.

It’s tempting to skip straight to the fun part – browsing furniture, choosing fabrics, pinning images – but without a clear budget, you’re making decisions in a vacuum. You might fall in love with a sofa you can’t afford, or hold back on the flooring when it’s actually the thing that would transform the room.

A well-built budget does three things. It shows you what’s realistic for the results you want. It helps you decide where to invest and where to save. And it gives you control over the timing – because if the total is higher than you’d like, you can phase the work rather than abandoning the project altogether.

Think of it as the foundation of the whole project. Get this right, and every decision that follows becomes easier.

Start by writing down every single item the room will need. Not just the obvious pieces like a sofa or dining table, but everything: flooring, lighting (both overhead and lamps), curtains or blinds, cushions, throws, artwork, rugs, shelving, accessories. Go into detail — for example, “1 x 3-seater sofa, 2 x armchairs, 4 x table lamps, 1 x rug (approx. 3m x 2.5m).”

Be thorough. The items people most commonly forget are window treatments, lighting, and the smaller accessories that actually make a room feel finished. These aren’t afterthoughts, they’re often what pulls a scheme together.

Next to each item, note whether it needs to be replaced, refreshed (perhaps reupholstered or repainted), or can be retained as it is. A spreadsheet works well for this, but a notebook is fine too.

This is where the surprises tend to start.

Put an estimated price against each item on your list. If you’ve recently furnished another room you may have a rough sense of current prices, but if it’s been a few years, it’s worth doing some fresh research.  Prices for furniture and furnishings have risen noticeably over the past couple of years, and what you paid five or ten years ago is unlikely to be a reliable guide.

The purpose here isn’t to choose specific products; it’s simply to understand the realistic price range for the quality level you’re aiming at. Browse at the level you’d actually want to buy at. For solid mid-range furniture, retailers like John Lewis give a reasonable benchmark. For higher-specification pieces, look at brands like Heal’s or Chaplins. If you’re drawn to bespoke or designer pieces, the numbers will be higher again.

To give you a rough idea of where UK room budgets tend to land in 2026:

A living room refresh (redecoration, new curtains, updated soft furnishings and accessories): typically £10,000–£15,000

A full living room redesign (new flooring, furniture, lighting, built-in joinery): £15,000–£40,000+

A bedroom refresh: £3,000–£8,000

A full bedroom redesign (fitted wardrobes, new flooring, all new furniture and soft furnishings): £25,000–£50,000

These are furnishings and finishes only – they don’t include structural work, kitchens, or bathrooms, which sit in a different cost bracket entirely. For a full home renovation across Cheltenham and the Cotswolds, overall investment (including building work, finishes, and furnishings) typically starts from around £150,000 for a substantial project and can reach significantly higher depending on specification and scope.

The figures above are intended as a starting point, not a ceiling. The important thing is to use real, current prices rather than assumptions.

If your project involves any physical work (painting, flooring installation, joinery, electrical changes, upholstery etc) list out the trades you’ll need to involve. Common ones include:

– Painter and decorator
– Flooring contractor
– Upholsterer
– Curtain maker and installer
– Electrician (for new lighting circuits or socket changes)
– Handyman or general contractor
– Joiner or cabinet maker (for bespoke shelving or built-ins)

If you’re doing a more extensive renovation that involves structural changes, plumbing, or heating, the list will be longer and the costs substantially higher.

If you haven’t had work done recently, ask around. Friends, family, and neighbours who’ve had similar work completed can give you a useful steer – though it’s worth checking that their expectations of quality match yours, as trade pricing varies considerably depending on the standard of work.

For the most accurate picture, contact the tradespeople directly for estimates. Some may give a ballpark over the phone or by email for straightforward work, and a home visit and written quote for anything more involved.

Labour costs in the UK have risen notably — skilled tradespeople in the South West and Cotswolds area are in high demand, and 2026 day rates reflect that. It’s better to know this upfront than to discover it mid-project.

If you’re using a spreadsheet, set up columns for the item description, estimated unit price, quantity needed, and line total. Use a simple formula to calculate the overall figure.

If you’re working on paper, the maths is the same, it just takes a little longer.

Once you have a total, add a contingency of 10–15%.  Every project has surprises, whether that’s a flooring issue hidden under the carpet, an electrical circuit that needs upgrading, or simply the discovery that the curtain fabric you wanted has a 12-week lead time and the alternative costs more. Building in a buffer from the start means these things don’t derail the project.

Look at the total. This is your starting budget.

Are you surprised by how high it is? Most people are. It doesn’t mean you’ve done something wrong, it usually means that the cost of quality furnishings and skilled tradespeople is higher than most people realise, particularly if it’s been a while since you last furnished a room from scratch.

If the number is broadly what you expected and you’re comfortable with it – excellent. You have a strong foundation to work from.

If it’s significantly more than you had in mind, don’t be discouraged. You haven’t committed to anything at this stage. This is a plan on paper, and there are practical ways to bring the figure into line.

Go back through your list and rank each item by importance:

1 for things that really matter to you,
2 for things that are important but flexible, and
3 for things that are lower priority.

For example, if you’ll be spending hours on the sofa each evening, comfort and quality matter – that’s a 1. If you have dogs or young children, the rug might need replacing in a few years anyway, so a less expensive option could be perfectly sensible – that’s a 3. Artwork might be prints to start with, upgraded to original pieces over time – that’s a 2.

By assigning priorities, you can adjust the specification for each item accordingly. Invest in the pieces that matter most, and be pragmatic about the rest. This is what designers sometimes call “layering”; mixing higher-quality anchor pieces with more affordable supporting items. Done well, it creates a room that feels considered and cohesive, and most people genuinely can’t tell which pieces cost more and which didn’t.

If the total still doesn’t sit comfortably, consider phasing the project. Tackle the most impactful elements first and plan subsequent phases for later. A well-thought-out phasing plan means you’re not compromising on quality, you’re just spreading the investment over time.

A few things regularly catch homeowners out:

Delivery and installation. Many furniture retailers charge separately for delivery, and pieces like curtains, blinds, and built-in joinery all have fitting costs on top of the product price.

Lead times. Bespoke and made-to-order items often have lead times of 8–16 weeks. If you need temporary furnishings in the meantime, that’s an additional cost.

The “while we’re at it” effect.  Once you start updating one part of a room, everything around it starts to look tired. A new sofa can make the existing curtains look dated. New flooring can highlight that the skirting boards need repainting. Try to anticipate this in your original list, it’s much cheaper to include these items from the start than to retrofit them later.

Contents insurance. Once you’ve invested in new furnishings, check that your contents insurance reflects the current replacement value. It’s a detail that’s easy to overlook, but important to get right.

Going through this process (even if it feels like a lot of work) gives you something invaluable: clarity. You’ll know what’s realistic, what your priorities are, and where you have flexibility. That puts you in control of every decision that follows, and it means you’re far less likely to be caught out by unexpected costs along the way.

It also means that when you do start making selections, whether on your own or with professional help, you’re choosing from a position of knowledge rather than guesswork. And that makes the whole experience more enjoyable, not less.

Whether you’re managing the project yourself or working with an interior designer, a clear budget is the starting point for everything. It’s the single thing that keeps aspirations and reality aligned — and it’s how the best projects stay on track from beginning to end.

Putting together a detailed room inventory and building a realistic budget is something we do with our clients at the very start of every project. It’s part of our foundation stage, and it’s where a lot of the most important decisions get made – before any designing begins.

We’re also able to source from trade-only suppliers, which means access to a wider range of products, greater customisation, and often better value than retail pricing for the same quality.

If you’d like to talk through your plans — even if you’re just at the early thinking stage — you’re welcome to tell us about your project. There’s no obligation, and it helps us understand your situation so we can point you in the right direction.

Julia Murray

Founder & Senior Designer, The House Ministry