How to read the building specifications (memoria de calidades)
The memoria de calidades is the developer's written description of how your home will be built and finished. Read it line by line, compare it with other projects, and make sure it is attached to your contract.
By Investidad advisory team · Last reviewed 16 Oct 2026
What the memoria de calidades is
When you buy Off-plan, you cannot inspect the finished home. What you can inspect is the Memoria de calidades: the developer's document listing the structure, materials, installations and finishes of the building and of each home. Together with the plans, it is the main evidence of what you are paying for.
Spanish consumer rules support you here. Real Decreto 515/1989 requires the seller of a home to have available, among other things, the plans of the home and a reference to the materials used in its construction, including thermal and acoustic insulation. It also provides that information about construction, services and installations given in offers and advertising can be enforced even if it is not repeated in the contract. That is a useful backstop, but a specification attached to the contract is far easier to rely on than a brochure.
What a good specification covers
Specifications vary from a single page of adjectives to a detailed technical schedule. A useful one names systems, materials and, where it matters, brands or performance values. Use this as a checklist:
- Structure and foundations
- WHAT TO LOOK FORType of structure (usually reinforced concrete), reference to the geotechnical study and to the building code
- WARNING SIGNSNo mention at all; structure described only as 'high quality'
- Façade and insulation
- WHAT TO LOOK FORFaçade build-up (outer leaf, insulation, inner leaf), insulation type and thickness, ventilated façade or external insulation system if any
- WARNING SIGNSInsulation not specified; 'according to regulations' with no detail
- Windows
- WHAT TO LOOK FORFrame material (aluminium with thermal break, PVC), double or triple glazing, low-emissivity glass, shutters or blinds and whether they are motorised
- WARNING SIGNSNo thermal break; glazing type missing
- Heating, cooling and hot water
- WHAT TO LOOK FORSystem (for example aerothermal heat pump), how heat is delivered (underfloor, ducted, fan coils), cooling included or only pre-installed, ventilation system
- WARNING SIGNS'Pre-installation' of air conditioning presented as air conditioning
- Kitchen
- WHAT TO LOOK FORCabinet and worktop material, which appliances are included and their brand or energy class
- WARNING SIGNSAppliances listed as 'optional' or not listed
- Bathrooms
- WHAT TO LOOK FORSanitary ware and taps (brand or range), shower trays or baths, tiling heights, furniture and mirrors
- WARNING SIGNSNumber of bathrooms in the plans differs from the specification
- Flooring and interior
- WHAT TO LOOK FORFloor material and format in each room, interior doors, wardrobes (fitted and lined or not), ceiling finishes
- WARNING SIGNSSame finish described differently in different documents
- Electrics and telecoms
- WHAT TO LOOK FORElectrical grade, number of sockets, telecom infrastructure, home automation if promised, electric vehicle charging provision in the garage
- WARNING SIGNSSmart home features named only in marketing
- Communal areas
- WHAT TO LOOK FORPool (heated or not), gardens, gym, lifts, access control, garage and storage rooms, solar installation
- WARNING SIGNSAmenities in renders but absent from the specification
| ELEMENT | WHAT TO LOOK FOR | WARNING SIGNS |
|---|---|---|
| Structure and foundations | Type of structure (usually reinforced concrete), reference to the geotechnical study and to the building code | No mention at all; structure described only as 'high quality' |
| Façade and insulation | Façade build-up (outer leaf, insulation, inner leaf), insulation type and thickness, ventilated façade or external insulation system if any | Insulation not specified; 'according to regulations' with no detail |
| Windows | Frame material (aluminium with thermal break, PVC), double or triple glazing, low-emissivity glass, shutters or blinds and whether they are motorised | No thermal break; glazing type missing |
| Heating, cooling and hot water | System (for example aerothermal heat pump), how heat is delivered (underfloor, ducted, fan coils), cooling included or only pre-installed, ventilation system | 'Pre-installation' of air conditioning presented as air conditioning |
| Kitchen | Cabinet and worktop material, which appliances are included and their brand or energy class | Appliances listed as 'optional' or not listed |
| Bathrooms | Sanitary ware and taps (brand or range), shower trays or baths, tiling heights, furniture and mirrors | Number of bathrooms in the plans differs from the specification |
| Flooring and interior | Floor material and format in each room, interior doors, wardrobes (fitted and lined or not), ceiling finishes | Same finish described differently in different documents |
| Electrics and telecoms | Electrical grade, number of sockets, telecom infrastructure, home automation if promised, electric vehicle charging provision in the garage | Smart home features named only in marketing |
| Communal areas | Pool (heated or not), gardens, gym, lifts, access control, garage and storage rooms, solar installation | Amenities in renders but absent from the specification |
Reading between the lines
- 'Or similar quality': most specifications let the developer substitute a material or brand 'or similar'. That is normal, but ask for the clause to require equivalent or higher quality and written notice of any change.
- Pre-installation is not installation: 'preinstalación de aire acondicionado' means ducts or conduits, not working equipment. Check exactly what you will have on the day you get the keys.
- Upgrades and options: if the developer offers a choice of finishes or paid upgrades, get the chosen options and their prices in writing, signed by both parties.
- Compare with the energy certificate: the insulation, windows and heating described should be consistent with the project's energy rating. See energy ratings and running costs.
- Compare projects line by line: two homes at similar prices can differ greatly in windows, heating and kitchen equipment. The specification is where that difference shows.
Attach it to the contract
The specification and the plans should be signed annexes to the private purchase contract, not documents you were shown once. If the reservation agreement or deposit contract is signed first, ask for the version of the specification in force on that date to be attached as well. Your lawyer should check that the contract sets out what happens if the developer changes a material: notice, equivalent quality and, for substantial changes, your right to object.
Questions buyers ask
- Can the developer change the materials after I sign?
- Most contracts allow substitutions of equivalent quality, often for technical or supply reasons. They should not allow lower quality. Ask your lawyer to tighten the clause before you sign and to require written notice of any change.
- Is the brochure part of the contract?
- Under Real Decreto 515/1989, information on construction, services and installations in offers and advertising can be enforced even if the contract does not repeat it. In practice, a dispute is far simpler if the specification is a signed annex to the contract.
