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RES022Residential

Official measure title

Rehabilitación de buhardillas o desvanes no habitables de edificios de viviendas.

Download the official PDF sheetView the official MITECO sector page
RES022

What this sheet covers

Sheet RES022 covers “Rehabilitación de buhardillas o desvanes no habitables de edificios de viviendas.”. It is a standardised sheet under Spain’s CAE scheme: it defines the scope of the measure and the official method for quantifying final-energy savings when its conditions are met.

Operational summary

Who it is for

Owners' associations, single-family homeowners and insulation contractors working on the top floor of an existing residential building that has an unoccupied loft or attic above the dwellings.

What is installed

Thermal insulation is laid over the floor slab separating the dwelling from the unoccupied space, usually blown or rolled mineral wool, until the U-value required by CTE DB-HE for the building's climate zone is reached.

Where the saving comes from

The saving comes from lowering the slab's thermal transmittance: fewer heat losses in winter and fewer gains in summer, so the heating and cooling systems run for fewer hours.

How to apply it

Before matching a project to RES022, confirm that the baseline, implemented solution, dates, equipment or areas and evidence fit the scope in the PDF. Then apply its formula using traceable data and collect the required documentation.

Eligibility conditions

  • Existing residential building with a building permit predating the applicable CTE version.
  • Upper space that is unoccupied and unconditioned (loft or attic) above dwellings in use.
  • Initial slab transmittance above the requirement and final transmittance meeting the climate-zone limit.
  • Treated area measured in plan and evidenced by a calculation note or drawing.
  • Work carried out and invoiced within the period accepted by the CAE scheme.
  • The measure must not have received support that is incompatible with CAE generation.

Calculation method

Final energy saving

Saving (kWh/year) = A × (U_initial − U_final) × HDD × 24 / 1000 / η

A
insulated slab area, in m².
U_initial
thermal transmittance before the works (W/m²K).
U_final
thermal transmittance after the works (W/m²K).
HDD
heating degree days for the climate zone.
η
seasonal efficiency of the existing heating system.

Evidence to collect

  1. 01Installation invoice itemising material, area and labour.
  2. 02Proof of payment for the invoice.
  3. 03Insulation datasheet with declared conductivity and CE marking.
  4. 04Calculation of initial and final transmittance with the climate zone used.
  5. 05Photographs before, during and after, with visible thickness.
  6. 06Proof of ownership and the CAE assignment agreement.

Mistakes that get the application refused

These are the most frequent refusal grounds during application review. Avoiding them speeds up CAE validation.

  • Insulating a space that is already conditioned or habitable, outside the sheet's scope.
  • Declaring a larger area than the invoice or drawing shows.
  • Failing to document the initial transmittance, which makes the U-value gap unverifiable.
  • Using the province's climate zone instead of the municipality's, including altitude.
  • Photographs that do not evidence thickness or continuity of the insulation.
CAE calculator · RES022

Estimate your certifiable energy savings.

Three questions to find out the annual saving in kWh that can be certified under this official sheet. No sign-up, no commitment.

Step 1 of 333%

Where is the building?

Province and altitude to determine the climate zone.

Type and pick an address from the list. We use it only to read the official altitude and climate zone.

or

Optional. Retrieves municipality, altitude and, when available, year of construction and surface.

Get your personalised study

An engineer reviews your case, confirms eligibility and tells you the CAE incentive amount.

Indicative, non-contractual estimate. It does not guarantee eligibility, issuance or valuation of CAE.

RES022: frequently asked questions

Can RES022 be used to convert the loft into living space?

No. The sheet applies precisely when the upper space stays unoccupied and unconditioned. If it becomes a dwelling, the project falls outside its scope.

What insulation thickness is required?

There is no fixed thickness: it depends on the material's conductivity and the climate-zone transmittance limit. The calculation sets the thickness needed to meet the required final value.

Can it be combined with other sheets in the same building?

Yes, provided each measure is documented separately and the same saving is not counted twice on the same building element.

Who owns the saving?

The property owner or the owners' association, which can assign the right to generate CAEs through the relevant assignment agreement.

Does the on-page calculator replace the study?

No. It gives a kWh/year estimate using the official methodology, useful for judging the project before commissioning the full study and documentation.

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