What to check in the reservation agreement and the off-plan purchase contract
An off-plan purchase usually runs through two documents: a short reservation agreement and the private purchase contract. The contract fixes the price, payments, specifications and delivery date, and must carry the guarantee details. Here is what to read for in each.
By Investidad advisory team · Last reviewed 16 Oct 2026
Two documents, two jobs
The reservation agreement takes a unit off the market for a short period while your lawyer checks the project. The private purchase contract is the binding sale: it sets out what you are buying, for how much, when you pay and when the home will be delivered. Ownership passes later, when you sign the title deed.
Resale homes are more often bought with an Arras contract. New-build sales normally use the reservation and purchase contract instead, so read the clauses on withdrawal rather than assuming the arras rules apply.
The reservation agreement
- The unit: the exact home, parking space and storeroom, with the price and the payment plan the developer is offering.
- The fee: how much, into which account, and whether it counts towards the price.
- Refund conditions: whether you get the fee back if your lawyer's checks raise a problem or you decide not to proceed, and by when you must sign the purchase contract.
- What happens if the developer withdraws the offer or changes the price before the contract is signed.
Before you reserve, your lawyer should already be checking who owns the plot and what is registered against it with a Nota simple, and whether the building licence has been granted; see checking the licences.
The private purchase contract: the key clauses
- Description of the home
- WHAT TO LOOK FORUnit, floor, useful and built area, annexes (parking, storage), and the plans attached.
- Specifications
- WHAT TO LOOK FORThe Memoria de calidades attached to the contract, and how changes to materials are handled.
- Price and payments
- WHAT TO LOOK FORTotal price, IVA shown separately, each stage payment and its date or milestone. See payment plans.
- Guarantee and account
- WHAT TO LOOK FORThe bank or insurer guaranteeing your payments and the special account, as the LOE requires.
- Delivery date
- WHAT TO LOOK FORA specific date or period, any grace period, and what counts as delivery. See delays and handover.
- Termination
- WHAT TO LOOK FORYour rights if construction does not start or the home is not delivered on time, and the developer's rights if you miss a payment.
- Costs
- WHAT TO LOOK FORWho pays which completion costs, and your right to choose the notary.
- Developer's mortgage
- WHAT TO LOOK FORWhether the developer's construction loan will be cancelled on your unit or whether you may take it over (subrogation), and on what terms.
| CLAUSE | WHAT TO LOOK FOR |
|---|---|
| Description of the home | Unit, floor, useful and built area, annexes (parking, storage), and the plans attached. |
| Specifications | The Memoria de calidades attached to the contract, and how changes to materials are handled. |
| Price and payments | Total price, IVA shown separately, each stage payment and its date or milestone. See payment plans. |
| Guarantee and account | The bank or insurer guaranteeing your payments and the special account, as the LOE requires. |
| Delivery date | A specific date or period, any grace period, and what counts as delivery. See delays and handover. |
| Termination | Your rights if construction does not start or the home is not delivered on time, and the developer's rights if you miss a payment. |
| Costs | Who pays which completion costs, and your right to choose the notary. |
| Developer's mortgage | Whether the developer's construction loan will be cancelled on your unit or whether you may take it over (subrogation), and on what terms. |
Rules that protect you as a consumer
- The contract must mention the guarantee: under the LOE, it must state that the developer will repay your payments with interest if construction does not start, the home is not finished on time or the first-occupation licence is not obtained, and must name the guarantor and the special account.
- Advertising is binding: under Real Decreto 515/1989, specific information in the brochure or advertising about the building, location, services, installations and payment can be enforced even if it is not repeated in the contract. Keep copies.
- The seller's title costs are not yours: on a first sale, a clause making you pay costs that legally fall on the seller, such as declaring the new building or dividing it into units, is not permitted under Real Decreto 515/1989.
- You may choose the notary, and one with no reasonable connection to the property cannot be imposed on you.
- No references to documents you have not received: the contract should not rely on texts that are not given to you before or with it.
Questions buyers ask
- Is the reservation fee refundable?
- Only if the reservation agreement says so. Read the refund conditions and the deadline for signing the purchase contract before you pay.
- Can the developer change the specifications?
- Changes should be governed by the contract and the memoria de calidades attached to it. Under Real Decreto 515/1989, extra charges must correspond to real additional services that you freely accept, and the exact amount of any change for unforeseeable reasons must be communicated and accepted by you.
