Investment approach
How to compare two flats: weights, full cost and risks
First impressions depend on the weather and staging, not on the flat. A table with weights, full cost per usable metre and a count of risks show where feeling and calculation part ways.
Two flats are compared by one scheme: criteria with weights, full cost per usable metre and open risks, all written down before the viewings. Usable area in Spanish valuation rules is the floor inside the outer walls without partitions, columns and outdoor spaces such as terraces (art. 4 of Orden ECO/805/2003), so the metres in listings are first brought down to it. The decision remains the buyer's, but errors of perception become visible.
Why the first impression deceives
The first impression describes the conditions of the viewing, not the flat. Flat A was seen on a sunny morning with flowers on the table, flat B on a rainy evening when tenants were living in it. Light, staging and the order in which rooms are shown work on the impression, while the flat itself does not change.
There is a reverse effect too: after a long search one wants to finish, and the faults of the last option seem small. Against both distortions one thing helps: a structure written down in advance.
Which criteria to write down before the viewings
The criteria are drawn up before both flats are seen, otherwise they adjust to the one that was liked. It is convenient to divide them into three groups.
- Red lines. Without which an option drops out at once: the number of bedrooms, a lift for an elderly parent, the time to school.
- Important. Light, noise, layout, outdoor space, the condition of the building.
- Nice to have. View, a neighbourhood for walks, the style of the building. It counts but does not decide.
Five to seven criteria are enough. Twenty items turn the comparison into bookkeeping, in which the main thing drowns.
How to calculate scores and full cost: a worked example
Worked example, not a forecast. Flat A costs 480,000 €, has 75 m² of usable area, needs light refurbishment and the owners' association has already approved a derrama (special assessment) for the facade. Flat B costs 450,000 €, 80 m², but needs new wiring and plumbing. Both cost less than 600,000 €, so ITP (transfer tax) in Catalonia is 10% (ATC). The refurbishment sums are assumptions.
| Item | Flat A | Flat B |
|---|---|---|
| Price | 480,000 € | 450,000 € |
| ITP 10% | 48,000 € | 45,000 € |
| Refurbishment, assumed | 10,000 € | 60,000 € |
| Approved derrama | 6,000 € | 0 € |
| Full cost | 544,000 € | 555,000 € |
| Per usable m² | about 7,253 € | about 6,938 € |
Flat B is cheaper in the listing but dearer in total, and per usable metre it is cheaper again. No single figure decides for the buyer, but both show that comparing by listing price misleads.
Scores are calculated just as simply. Each important criterion is given a weight from 1 to 3, each flat is scored on a scale of 1 to 5, the score is multiplied by the weight and the results are added. If the table says "B" and the feeling says "A", it is worth working out which criterion has been undervalued. Filling in the scores is convenient for two people, but separately: the disagreements between partners are the most useful part of the exercise.
How to compare the risks of two flats
Price and convenience are half of the picture; the other half is what can go wrong. For each flat note:
- Documents: nota simple (land-registry extract), debts to the community, cédula (habitability certificate), discrepancies between the area and the listing.
- The building: age, ITE (technical building inspection), recent works, minutes of meetings.
- The technical side: damp, wiring, pipes, windows.
- Legal particulars: a tenant, an inheritance, several owners.
- Price relative to the market: a flat above comparable transactions may turn out dearer even if its price is lower than the other flat in the table.
A flat with fewer comfort points but clean documents sometimes beats a prettier one with three open questions. How to check the price against transactions is covered in the article on valuation by real transactions, and how to read metres and rooms in the article on the floor plan.
How to check daily life and resale
A table does not replace living in a flat, but a few checks come close. The second visit is made at a different time: in the evening on a weekday, when the bars downstairs are open. The route to work and school is driven at rush hour. And a sale a few years out is imagined: which of the two flats will find a buyer sooner.
For that last question a market guide is useful: according to idealista, in Q2 2026, 36% of housing sold through the portal in Spain spent from three months to a year in listings, and 11% more than a year (idealista). How to measure the liquidity of a specific property is described in the article on property liquidity.
When this comparison does not work
The table does not work if one of the flats fails a red line: comparing further is pointless. It also does not help when an option has a big question open, for example a change of layout without a licence or an unclear source of damp: that is first closed by the abogado (lawyer) or the technician, and only then are the points counted.
And finally, comparing two flats does not answer the question of whether the price of either is good. If both are listed above the market, the one with more room for haggling wins. DNPI carries out an independent valuation of both flats against transactions as part of a value analysis.
Questions and answers
How do I choose between two flats if I like both?
Write down five to seven criteria with weights, score the flats separately and calculate the full cost with tax, refurbishment and charges per usable metre. If the difference is minimal, risks and resale decide.
What matters more: price or location?
Price can be partly changed by negotiation and refurbishment; location cannot. So options are first screened by district and commute, and prices are compared among the suitable ones afterwards.
Which area should be compared in listings?
The usable one. Under Orden ECO/805/2003 it is the floor inside the outer walls without partitions, columns and outdoor spaces, while listings often show the built area including common parts.
Can a second flat be kept in reserve while negotiating over the first?
Yes, and it is useful: a real alternative strengthens the negotiating position. But in an active segment the reserve option may go to another buyer.
Does tax need to be counted when comparing flats?
Yes, if the prices fall on either side of a threshold of the ITP scale or one of the flats is a new-build with IVA (VAT). For resale housing up to 600,000 € in Catalonia the rate is the same, 10%.
