Renovate to add value: the improvements with the highest return

Buy a flat, renovate it and sell or rent it for more than you invested. The idea is simple. The execution, not so much. The return on a renovation depends on which improvements, in what order, with what budget and in what area. This article ranks improvements by their real impact on property value, with concrete figures and the mistakes that cost the most money.

How much does a renovation add in Spain?

According to Spanish appraisers and property portals, a quality mid-to-high renovation can add between 10 % and 30 % to a property's pre-renovation value. In high-demand areas like Alicante, Valencia or the coasts, the range is 15-25 %. In areas with less demand pressure, the return can be lower than the renovation cost — and that is an expensive mistake.

The key is not how much you spend, but where you spend it. Some improvements have an ROI of 80-120 % (they return nearly all or more than the investment in added value). Others have an ROI of 30-50 % — they add value, but do not recoup the outlay.

The improvements that add the most value, ranked by ROI

1. Kitchen — ROI: 80-120 %

The kitchen is the number-one value driver. A buyer or tenant walks into the kitchen and decides in seconds whether they like the flat. An outdated kitchen with 1980s tiles can devalue an otherwise decent property. A modern, bright, functional kitchen transforms it.

Typical budget in Alicante: €6 000-15 000 (full renovation: units, worktop, appliances, lighting, floor, tiling). Mid-range kitchens with quartz worktop and integrated appliances offer the best balance between cost and perceived value.

What maximises return: light colours, LED under-cabinet lighting, quartz or composite worktop, integrated appliances, continuous flooring with the living room. What does not: luxury brands the buyer does not recognise, islands in small kitchens, exotic materials.

2. Bathroom — ROI: 70-100 %

The second most influential space. A bathroom with yellowed tiles, an old bathtub and rusty taps says 'old flat' more than anything else. Replacing the bath with a walk-in shower, renewing sanitary ware, modernising the tiling and adding a large mirror transforms the perception of the entire property.

Budget: €3 000-8 000 per bathroom. If the flat has two, renovate at least the main one.

What maximises return: flush-level shower tray, frameless glass screen, vanity unit with storage, simple-design taps in matte black or chrome, mirror lighting.

3. Energy efficiency — ROI: 60-90 %

The energy certificate is now mandatory in Spain for selling or letting. A flat rated E, F or G is perceived as a future expense; one rated B or C is perceived as a smart investment. Energy improvements not only add value — they reduce bills.

Best cost-to-impact actions:

• Double-glazed windows with thermal break: €3 000-6 000 for an 80 m² flat (4-6 windows). Improve the certificate by 1-2 grades and reduce noise.
• Facade or cavity insulation: €2 000-5 000 if done internally (blown-in). More expensive externally.
• Heat pump / aerothermal: €3 000-7 000 installed. Replaces old boilers and improves efficiency dramatically.

Grants for energy rehabilitation in the Valencian Community (Next Generation EU funds) can cover 40 to 80 % of these improvement costs. Check IVACE or your local council.

4. Layout redistribution — ROI: 50-80 %

Many 1970s-80s flats have layouts with long corridors, closed kitchens and small rooms. Opening the kitchen to the living room, removing a partition to create a spacious living-dining area or converting a service room into a walk-in wardrobe can transform an 80 m² flat that 'feels small' into one that 'feels large'.

Budget: €2 000-6 000 (demolish partition, reinforce if needed, level floors). If plumbing or electrics need moving, it rises to €4 000-10 000.

Caution: never touch a load-bearing wall without a technical report. Demolishing a structural partition without a permit is not only illegal — it can compromise the building's safety.

5. Flooring — ROI: 40-70 %

1970s terrazzo or worn ceramic tiles age the entire flat. Replacing them with laminate, vinyl or large-format porcelain updates the aesthetics with immediate impact.

Budget: €2 000-5 000 for 80 m² (material + installation). SPC vinyl is the most popular option for its water resistance, ease of installation and competitive price (€15-30/m² installed).

6. Paint and finishes — ROI: 200-400 %

The highest ROI on the list, but on a very small investment. Painting an 80 m² flat costs €1 000-2 500 and can completely transform the first impression. Neutral colours (off-white, light grey, soft beige), white ceilings and painted skirting boards.

It is the mandatory improvement in any renovation — there is no excuse not to paint.

Improvements with low return

Not everything that costs money returns it:

• Private pool: cost €15 000-30 000, return 20-40 %. Only justified in high-value villas where the buyer expects it.
• Full home automation: interesting but not recoverable. The average buyer does not pay more for a system they do not know how to use.
• Ultra-luxury materials: imported marble, designer taps, exotic wood. In a €2 000/m² area, nobody pays a premium for €5 000/m² materials. Luxury must be proportional to the zone.
• Illegal extensions: enclosing a terrace without a permit or extending without permission. Illegally gained square metres cannot be registered, cannot be mortgaged and can trigger planning sanctions.

Order matters

If your budget is limited, prioritise in this order:

1. Paint (always, it is the first expense)
2. Kitchen (if over 15 years old)
3. Main bathroom (if over 15 years old)
4. Flooring (if deteriorated or dark terrazzo)
5. Windows (if aluminium without thermal break)
6. Layout (only if the current layout penalises the perception of space)

With a budget of €15 000-20 000 you can tackle the first three improvements. With €30 000-40 000 you can do a full renovation that transforms a €100 000 flat into one worth €130 000-140 000.

Mistakes that destroy the return

• Over-specifying for the area: investing €50 000 to renovate a flat whose post-renovation market value is €130 000 leaves a margin that does not justify the risk and time.
• Working without a permit: any structural modification, change of use or facade alteration requires a municipal licence. Illegal works not only fail to add value — they can devalue if the buyer detects the irregularity.
• Choosing materials that do not match the local market: a flat in Torrevieja does not need the same quality finishes as one in Jávea. Match the renovation to the buyer or tenant profile of the area.
• Not controlling timelines: every month the flat is under renovation is a month without rent. If the renovation stretches from 2 to 4 months, you have lost €1 500-2 000 in uncollected rent.
• Renovating without a sale or rental plan: renovating 'just because' without knowing at what price you will let or sell is investing blind. Calculate the expected return before signing the budget.

Frequently asked questions

Is it better to renovate before selling or sell as-is?

It depends on the margin. If you can invest €15 000 and that raises the sale price by €25 000-30 000, renovate. If the margin is €5 000-8 000, it does not justify the risk and time. Also, many investor-buyers prefer to buy unrenovated to control the renovation to their own taste — offering a competitive unrenovated price can be equally effective.

Do I need a permit to renovate?

For cosmetic renovations (paint, flooring, kitchen units, sanitary ware) you do not need a permit — a prior notice to the council suffices. For works affecting the structure, layout or main services, you need a minor works licence. For works altering the building envelope or its use, you need a major works licence and a technical project signed by an architect.

How long does a full renovation take?

A full renovation of an 80-100 m² flat (kitchen, bathroom, flooring, paint, electrics, plumbing) takes 6 to 12 weeks on the Costa Blanca. The factors that stretch it most: municipal permits (2-4 weeks), material delays (especially imports) and coordination between trades (electrician, plumber, builder, painter).

Are energy rehabilitation grants accessible?

Yes, but the bureaucratic process can be slow. Next Generation EU grants for energy rehabilitation in the Valencian Community cover 40 % to 80 % of costs depending on the improvement in energy certification. Resolution times vary and it is advisable to apply before starting works, not after. Check with your council or IVACE for current programmes.

Is renovating an old flat better than buying new build?

Financially, it can be. An old flat in a good location bought at €1 500/m² and renovated with €300-500/m² can have a total cost of €1 800-2 000/m² — below new build in the same area (€2 500-3 500/m²). The difference is the investor's margin. But new build offers legal guarantees (10-year structural, 3-year systems), factory energy efficiency and modern communities that old flats lack.

If you are thinking of buying to renovate on the Costa Blanca, explore our available properties or contact us for a personalised consultation.